Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Compact Battery Switch with Dual Sense VSR

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Compact Battery Switch with Dual Sense VSR
jimh posted 05-25-2011 08:34 AM ET (US)   Profile for jimh   Send Email to jimh  
BEP has an interesting product which will be useful on a single-engine small boat due to its compact size. It's their model 714-100A - SINGLE ENGINE, TWO BATTERY BANK battery distribution switch with dual sense voltage sensitive relay. The assembly combines a 701S battery selector switch and a 710-125A Dual Sensing voltage sensitive relay (VSR)

The switch is the familiar two-battery distribution switch that allows the load to be switch to either battery. The voltage sensitive relay is a dual sense design. In this way it will combine the two batteries in parallel whenever either one of them is being charged.

701S Switch

710-125A Dual Sense VSR dual-sense-voltage-sensitive-relay-125amp-vsr-

714 Cluster 714-100a-single-engine-two-battery-banks

jimh posted 05-25-2011 08:40 AM ET (US)     Profile for jimh  Send Email to jimh     
Because the VSR is dual sensing, the off-line battery will always be charged whenever there is excess charging current available, that is, when the on-line battery voltage is above threshold (13.7-Volts). The wiring of the VSR is very compact due to its integration into an assembly with the switch. Only a single extra lead (a small gauge wire for the battery negative) is required, and otherwise the device is no more complex than a normal battery switch. This will provide for a very simple and clean installation, which is welcomed on a small boat.
jharrell posted 05-25-2011 11:18 AM ET (US)     Profile for jharrell    
The most direct competitor to the BEP kit is the Blue Sea System "Add a Battery" kit:

I considered both for my Montauk when adding a second battery to it.

The main difference between the two is [described incorrectly the difference because the comparison was being made to a different BEP product, not the one under discussion--jimh].

The BEP kit also has short (#6 I believe) wires preconnected to the VSR from the switches underneath the cluster. With the Blue Sea you must provide those leads yourself.

I choose the Blue Sea kit over the BEP offering for my Montauk primarily because the single switch design allows me to turn the boats electrical system on and off with one switch instead of two. [Actually, the BEP model 714 is a single switch. Again, there is some confusion in the comparison because the wrong BEP product is being compared--jimh]

The BEP design allows easier installation while the Blue Sea offers easier operation in my opinion.

The Blue Sea ACR also has optional leads for an external status LED and ignition isolator(which forces the ACR to disconnect when the engine is starting) which I don't believe the BEP VSR has. I am however not currently using these optional leads.

jharrell posted 05-25-2011 11:56 AM ET (US)     Profile for jharrell    
I have read elsewhere that the BEP VSR can be prone to chatter when the voltage fluctuates as when one battery is significantly discharge when the charging source is applied.

BEP's own literature discusses this behaivor:

"Q: Why does my VSR ‘chatter’?
A: Because the charging system is too small for the batteries and
this is not allowing the VSR to work properly. Instead, once the
starting battery has reached the right voltage and the house battery
is connected the systems voltage is ‘caving down’ below 2.7 volts
and the relay is automatically disconnecting. The voltage then rises,
the relay re-engages; then the voltage drops the relay disengages
and the ‘chattering’ sound is heard as the relay quickly switches in
and out. Refer to battery sizing chart on next page."

Blue Sea's ACR seems to be equipped with a pretty agressive Hysteresis ciruit to prevent chatter:

"Blue Sea Systems’ 120A SI ACR (7610) is programmed to prevent cycling when combining battery banks. It will remain closed and keep the battery banks combined usually long enough for the system voltage to recover. When two battery banks are combined, if the secondary battery bank draws down the system voltage, the 7610 will remain closed if the system voltage rises to at least 12.35V within ten seconds and at least 12.75V within 30 seconds. If the system voltage rises to these levels, the battery banks will remain combined. The 7610 recognizes rising voltage between 12.35V and 12.75V as a signal that charging is occuring even though the voltage is still below the normal drop out voltage of 12.75V."

This may be an advantage to the Blue Sea's ACR over the BEP. I have never seen the Blue Sea ACR chatter or cycle on my boat. It would be interesting to hear if anyone with the BEP VSR has experienced this.

jimh posted 05-25-2011 01:17 PM ET (US)     Profile for jimh  Send Email to jimh     
I think jharrel is talking about a different BEP product than the model 714 I am talking about. Perhaps a review of the links I mention above will help identify the model 714. It is a single switch, not a three switch. The compact nature of the 714 is the attraction for the small boat.
jimh posted 05-25-2011 01:51 PM ET (US)     Profile for jimh  Send Email to jimh     
The BEP VSR contains a hysteresis feature as has been attributed to other brands of battery combiner devices. For those not familiar with the term, hysteresis refers to the operation of a control circuit in which there is a dead-band range intentionally built into the control in order to suppress chatter or ON-OFF oscillation of the control system. Just about all control system have hysteresis incorporated; if they did not their operation would be prone to oscillation between states.

BEP literature explains their VSR hysteresis in their literature.

The OFF threshold (12.8-Volts) is lower than the ON threshold (13.7-Volts).

Since the BEP is intended for use with outboard engines, the charging capacity of the engine should be able to meet the recommended current for the charging source.

jharrell posted 05-25-2011 03:04 PM ET (US)     Profile for jharrell    
Yes I was too hasty in replying, the 714 only has a single selector switch which does not allow house loads to be run off the house battery and turned off unless a separate switch is introduced. With the 714 the entire electric system is switched between one battery or the other, with the VSR keeping the other battery charged but unused.

This is contrast to the 716 which has 3 switches and allows house and engine circuits to be isolated without additional components. 716-sq-100avsr-dual-battery-charging-cluster

Again the Blue Sea single switch does not flip flop between batteries, position 1 makes two independent connections for starting and house, position 2 combines both circuits. It is physically like the BEP 714 but functions more like the BEP 716.

As far as the hysteresis of the BEP VSR, it seems to only be voltage based not voltage AND time based like the Blue Sea.

This would still cause oscillation, cycling, or chatter in the scenario you described in the other thread where the VSR engages and the charger cannot supply the required current to keep the voltage above 12.8 volts. This is described in BEP's literature right after they describe their hysteresis: "A buzzerlike sound can be heard as the relay quickly switches in and out. Disengagement can occur at idle (low amps out due to slow speed of alternator) or if the house battery is at a low charge. An increase of the engine’s RPM will increase the alternator output and hold up
the voltage."

In contrast the Blue Sea ACR introduces a time component in it's hysteresis allowing voltage to be any value for the first 10 seconds after engaging, and can be between 12.35v and 12.75v for the next 20 seconds. This effectively eliminates chatter, and give the system time to equalize.

jimh posted 05-25-2011 06:05 PM ET (US)     Profile for jimh  Send Email to jimh     
The dual-sense VSR of the BEP model 714 is an important feature. No matter which battery is chosen as the on-line battery, the off-line battery can be charged as soon as there is excess charging current available.

The BEP model 714 eliminates a great deal of external wiring and external components needed with other devices. As I mentioned, the only additional component of the model 714 is a small-gauge wire which is run to the negative bus. Other than this there is no further complexity to the model 714 than there is to just a plain battery switch. In contrast, other battery management devices require a significant number of additional components, such as fuses, cables, connectors, terminals, and so on. Their cost will often be as great as the automatic relay device, and on an open boat it can be difficult to find a good place for all of those extra components.

The BEP model 714 seems to be very well suited for use on a small boat where a single engine and two batteries are employed.

It is not difficult to turn the primary power distribution system and battery management automation devices into rather complicated systems with many options and features, but on the small boat there is something to say for simplicity and compact size. I think the BEP model 714 fits those criteria.

jharrell posted 05-25-2011 06:50 PM ET (US)     Profile for jharrell    
The Blue Sea "Add-a-battery" system only requires a single fuse, not multiple fuses, and the same small gauge wire for negative.

It also requires two #6 or larger wires from the positive leads on the switch to positive leads on the ACR. These #6 wires still exist in the BEP 714, they are simply installed at the factory, which does save some cost and installation time.

I am not sure why the BEP system does not require a small fuse on the negative lead like the Blue Sea does, as this is a potential path to negative from the high current battery leads through the VSR and a fire danger if that where to occur. Perhaps the have an internal one time use fuse or are very confident in their internal relay design and deem it unnecessary.

The negative lead with inline 10 amp fuse cost less than $10 at West Marine, I would recommend this be used even with the BEP kit.

I see the Blue Sea kit as slightly more complicated and expensive to install while providing advantages over the 714 such as a more advanced relay less prone to chatter and the ability to have house loads run off a separate battery from the engine while still only having one switch to turn the whole system on and off.

jimh posted 05-25-2011 08:32 PM ET (US)     Profile for jimh  Send Email to jimh     
According the technical literature from BLUE SEA SYSTEMS, their Add-A-Battery system requires five or six additional fuses. See the diagram contained in their technical literature at

I think BLUE SEA SYSTEMS has some great products. I actually use their battery switch on my boat. But for the application in a small open boat with a single engine and two batteries, the BEP model 714 is a simple and compact device. Again, it is simple, compact, and requires few additional components.

jharrell posted 05-25-2011 10:10 PM ET (US)     Profile for jharrell    
I stand by my statement the only "required" fuse is a 10amp inline fuse on the negative lead, and this is one more fuse than the BEP design, which has no overload protection. This information comes from someone who discussed the issue with Blue Sea technical support.

Of 5-6 fuses number that you say are required, two of them in the diagram are on optional circuits, the remote LED and ignition disable. How can fuses be required when those whole circuits are optional, circuits which by the way are not available on either BEP kit?

They also show two 150amp fuses on the house power circuit, this obviously has nothing to do with the ACR's presence, and simply their recommendation for house circuit fusing.

Whats left are the 3 fuses tied directly to the ACR operation, a 50amp on each positive lead and a 10amp on the negative. Obviously the 10amp fuse will blow and protect against a short to ground long before the 50amps, so what could the 50amp fuses possibly be for if the the ACR and switch next to each other and the ACR is tied to the switch posts instead of battery post as is the case with the BEP setup? Nothing, the 50amp fuses are recommend only if the leads going to the ACR travel some distance through the boat risking some other possible short to ground.

The only other possibility you could argue is the 50amp fuses protect against some sort of catastrophic battery short, which is true it might mitigate such an event from propagating to the other battery, in that case the BEP's fuseless design would also suffer from having no protection and suffer the same fate.

jharrell posted 05-25-2011 10:16 PM ET (US)     Profile for jharrell    
Correction the large fuses recommend by Blue Sea are 80 amps, not 50.
jimh posted 05-26-2011 04:14 AM ET (US)     Profile for jimh  Send Email to jimh     
jharrell--If you wish to turn this thread into a debate about BEP and BLUE SEA SYSTEMS recommended installation practices, perhaps you could start a new thread for that topic. I did not intend that my mention of the compact battery switch with dual-sense VSR embodied by the BEP model 714 would become such a discussion. I think such a discussion would be an interesting topic, and if you want to investigate it further, please start a new thread.
jharrell posted 05-26-2011 01:18 PM ET (US)     Profile for jharrell    
I did not intend for this to turn into a debate, I simply wanted anyone interested in the topic "Compact Battery Switch with Dual Sense VSR" to have access to information another manufacturers solution to the topic.

I did not realize this topic should be limited to a single manufactures solution, perhaps the topic should read "BEP Marine Compact Battery Switch with Dual Sense VSR".

I honestly think there is very little more to be fleshed out, I know I would have found the information concentrated in this thread very useful when I was comparing BEP to Blue Sea's offerings and I am sorry you don't see it that way, but otherwise I have nothing to add.

jimh posted 05-27-2011 08:55 AM ET (US)     Profile for jimh  Send Email to jimh     
I don't see any mention that the Blue Sea Systems device is a dual sense device. Not being completely familiar with the Blue Sea Systems device, I don't know if it is or isn't. Perhaps we could have some clarification.

jharrell mentions:

"I choose the Blue Sea kit over the BEP offering for my Montauk primarily because the single switch design allows me to turn the boats electrical system on and off with one switch instead of two."

This decision would not apply to the BEP model 714 because the BEP model 714 is also a single switch. The comparison is not appropriate.

I don't have any objection to mention of similar products. I do find it confusing to introduce comparisons to different BEP switch assemblies other than the model 714.

As I said, you can turn the primary power distribution and automatic battery charging management into a relatively complicated system, if you like, but the BEP model 714 is a simple, compact alternative that requires almost no additional circuitry compared to a standard battery switch. The pre-assembly of the components of the model 714 into a single unit is attractive. On a small boat I would judge this to be advantageous to having to install two or more devices and then interconnect them using large gauge fused conductors. BEP's assembly of their components into a single device seems like good design to me. I am not aware of any similar device where the manufacturer has pre-assembled the components into a single unit. If there are other units, I would be pleased to hear of them.

K Albus posted 05-27-2011 09:26 AM ET (US)     Profile for K Albus  Send Email to K Albus     
If you use the BEP model 714 cluster, and both of your batteries are low, with the cluster allow you to combine the batteries?
jimh posted 05-27-2011 09:51 AM ET (US)     Profile for jimh  Send Email to jimh     
Kevin--That is a good question. From the literature I could not find an explicit answer. I assume their battery switch is of the usual OFF-1-BOTH-2 design, but BEP seems a bit dodgy about clearly saying that.
jimh posted 05-27-2011 09:56 AM ET (US)     Profile for jimh  Send Email to jimh     
The TITLE box in this drawing says "ONE, TWO, BOTH SWITCH." Sounds to me like the 701S switch does combine batteries:

K Albus posted 05-27-2011 09:59 AM ET (US)     Profile for K Albus  Send Email to K Albus     
Jim - There is some mention in the "Trouble Shooting" section of the PDF relating to the 714 cluster of "starting the engine with the emergency parallel," but neither the pictures of the cluster nor the description indicates that the switch includes a "Both" position.
K Albus posted 05-27-2011 10:04 AM ET (US)     Profile for K Albus  Send Email to K Albus     
The description of the 701-S Battery Switch includes the following: "Operation: 1-2-Both-Off". 701s-mini-selector-battery-switch

jimh posted 05-27-2011 11:20 AM ET (US)     Profile for jimh  Send Email to jimh     
Kevin--It actual says " 1-2-Both_Off" which you might read as meaning either "1" or "2" or "Both 1 and 2 off." Or, it could be sloppy typing on the webpage, which may be more likely.
K Albus posted 05-27-2011 12:17 PM ET (US)     Profile for K Albus  Send Email to K Albus     
Jim - I saw the "Both_Off" and figured it was a typo. I guess that was probably not a safe assumption.

It would be nice if they had a nice clear picture of the face of the switch.

andygere posted 05-27-2011 02:52 PM ET (US)     Profile for andygere  Send Email to andygere     
This is a nice option for a small boat, and takes up less room than the BEP 3 switch cluster. The trade-off seems to be that the house loads and the start load are not separated, but instead will draw off whichever battery is turned on. In theory, this seems fine, so long as there is always a battery that is isolated for starting if the "on" battery is drawn down by house loads. The key may be for the operator to manually shut down house loads during an emergency start condition so that the "preserved" battery is only used to power the starter motor until the engine is running. This seems like a reasonable compromise, and will simplify wiring particularly for someone who is adding a second battery to a single battery system.

I agree that it's unclear if there is a battery combine function, and the photos and descriptions are indeed vague on that feature. If it does in fact have a combine function, the lack of house and start separation by battery becomes even less important in my mind.

jharrell posted 05-27-2011 08:32 PM ET (US)     Profile for jharrell    
The Blue Sea ACR is a dual sense device. I can't find specific mention of it in the documentation, they do mention being to attach the charging source to either side.

I personally have my engine tied to one side and my charger tied to the other, and either charging source engages the ACR confirming it's dual sense design.

The BEP 714 does not have a combine, and I assumed you realized this fact. This is obvious by it's 3 terminal design, the 714 simply redirects it's common terminal between the a and b terminals or both off. The switch simply allows you two switch between one battery or the other, while the second battery becomes disconnected.

This is why I said you could not isolate your house circuit and turn it off with a single switch using the 714 kit, you would instead have to tie house directly to the house battery bypassing the 714 and add a separate house switch. This would be similar to the 716 design.

The Blue Sea switch on the other hand has 4 terminals, 2 for each circuit. position 1 connects the two terminals on each side independently keeping them isolated, position two connects all 4 terminals together for emergency combine. This allow one switch to turn off the entire boat while turning on house and starting circuits independently.

jharrell posted 05-27-2011 09:01 PM ET (US)     Profile for jharrell    
Ok I was wrong about the combine, the BEP 701s switch does have a combine position. It is not shown in their pictures or schematics, but I did find a head on photo here: 310531-bep-701-s-compact-battery-selector-switch.html[

What it does not do is keep house and starting isolated, this the 3 terminal design vs 4 for the Blue Sea.

jharrell posted 05-27-2011 09:04 PM ET (US)     Profile for jharrell    
Fixed link: 310531-bep-701-s-compact-battery-selector-switch.html
pcrussell50 posted 05-28-2011 12:13 AM ET (US)     Profile for pcrussell50  Send Email to pcrussell50     
This "feud" between Jim and jharrell has been the benefit of the rest of us. Keep it up, guys. :)


jimh posted 05-28-2011 08:34 AM ET (US)     Profile for jimh  Send Email to jimh     
The BEP 714 is a simple, compact single-assembly switch. It has only one output, so there is no question, debate, or issue about whether or not it maintains any separation between HOUSE and START loads; it does not. No one--not me, BEP, or the Astronauts that went to the moon--ever said it did.

The BEP 714 appears to be the classic OFF-1-BOTH-2 type of switch, a style we are all familiar with.

There are only one or two models of Blue Sea Systems battery switch which are designed to keep the HOUSE and START loads separate. Most of the battery distribution switches Blue Sea Systems make do not keep the loads separate. Their model 5511e does this, and maybe one other variation, but most of their switches do not. If you want the specialized switch from Blue Sea Systems, you have to get the special model. Don't be mislead into thinking all Blue Sea Systems switches do this; they do not. Most work just like the BEP 701S.

If you want to maintain separation between HOUSE and START loads, BEP makes an assembly that does this which uses three switches. I find the BEP approach is actually more flexible and gives more control than is offered by the single switch design of Blue Sea Systems. For example, the BEP three-switch assembly can keep the HOUSE loads ON while the START loads are OFF, or vice-versa. I probably would have purchased the BEP switch assembly for my own application, but I got the Blue Sea Systems 5511e primarily because it would fit into existing holes the bulkhead where the old switch was mounted and I did not want to make more holes.

As for the "feud", I can't say much, except to note that lately if I say something as simple as "The first letter of the alphabet is A," it seems to prompt an investigation into the concept of alphabetical order. Maybe everyone needs to go boating.

davej14 posted 05-28-2011 09:24 AM ET (US)     Profile for davej14  Send Email to davej14     
I agree that the first letter of the alphabet is "a". As to boating, the weather has been so lousy here in Upstate NY that my boat is still in storage. Every day a thunderstorm and another 1/2 inch of rain.
jimh posted 05-30-2011 10:12 AM ET (US)     Profile for jimh  Send Email to jimh     
Readers should recall that the primary purpose of CONTINUOUSWAVE is to collect and organize articles with high information content on its various subjects. As long as there is information contributed, I welcome all participants to the discussion.
jharrell posted 05-30-2011 12:09 PM ET (US)     Profile for jharrell    
I wouldn't call this a feud only a friendly debate, I hope jimh see's it that way as well. As far as debating alphabetic order, I would say jimh brings it out at least in me with his pedantic style in post and moderation.

Don't think that I am complaining. This site is an extremely valuable resource full of years high quality content easily searchable. This is no doubt because of jimh's moderation and attention to detail, so thank you.

Now back to the debate. I am not sure why the BEP 701s even has a combine position. Since it's single output can be switched between either battery, the combine seems to serve no purpose.

The Blue Sea 5511e provides all functions of the BEP 701s with the added benefit of keeping house and starting circuits isolated. It does all of this with one less switch position than the BEP.

When choosing a system for my Montauk one of my goals was running all electronics and jack plate off of the house battery, while keeping the starting dedicated only to the engine. This would not be possible with the BEP 714, which is why I only compared the Blue Sea with the BEP 716.

It is true the BEP 716 has some added flexibility with separate switches for house and starting and combine. I preferred the simplicity and ease of use of the single switch design. I already had a breaker on my house circuit which could be used to turn off house if needed.

As far as price, the Blue Sea add a battery kit is similar in cost to the BEP 714 while having the features of the more expensive BEP 716 and a more advanced relay than either BEP offering. However the BEP kits are assembled at the factory with leads ore made between switch and relay, the Blue Sea requires one to provide their own leads, this obviously adds to cost. In my install the total cost for the Blue Sea kit was similar to the price for the BEP 716.

jimh posted 05-30-2011 12:20 PM ET (US)     Profile for jimh  Send Email to jimh     
The purpose of the "BOTH" or "1+2" or "EMERGENCY" position on the various battery switches discussed here is all the same: to parallel the two batteries in order to create more battery power for situations that need more battery power than a single battery can provide. Most typically the situation which needs more battery power will be cranking over an engine for starting with an electric motor.
jharrell posted 05-30-2011 12:43 PM ET (US)     Profile for jharrell    
So if parallel is important for for emergency starting, then the number two position seems unnecessary, why would one switch over to the second battery if not for emergency starting?

As for your suggestion that we need to get out and boat, I agree. I just got back in from a overnight at a cabin near the gulf only accessible by boat. All this talk of electronics and batteries and engines is really all for this in the end: 7JomqfGcNGc/s1024/1000000011.JPG

pcrussell50 posted 05-30-2011 02:13 PM ET (US)     Profile for pcrussell50  Send Email to pcrussell50     
For the time being, while the "feud" rages, (please guys, it's a fun word, and I used quotes), I'm using this very basic setup, exactly as depicted:

I have a cheap, single sensing ACR sitting unused on the shelf, because I do not know how it will behave when the only charging source is a float/maintenance charger, which is how I like to leave my Alert, when not in use. The single float charger is working the batteries, paralleled through the BOTH position. I don't _like_ storing the boat with the switch in other than OFF, but for the time being, BOTH is what I've got, if I want to float charge. Thankfully, both batteries are the same age and model and one is never much more discharged than the other.

I may eventually decide to go Jim's way or Jharrell's, or some other way. It remains to be seen. In the mean time, I have to go "manual" and try not to leave the battery switch in BOTH while anchored, beached, or drifting.

Do some boating on your time off, guys. I'm all the way across the country, on a Pittsburgh layover.


jimh posted 05-30-2011 02:58 PM ET (US)     Profile for jimh  Send Email to jimh     
It actually is quite easy to find situations where a primary power distribution switch with an arrangement of OFF-1-BOTH-2 would be useful to running the electrical system on the second battery. For example, if there is a problem with the first battery. It is often seen that a battery will fail by having a cell short circuit. When this happens, the battery terminal voltage becomes about 2-Volts lower than it should. Leaving a battery with a short cell connected will create a drain on the electrical system. With a switch with OFF-1-BOTH-2 connection arrangement, it is a simple matter to isolate the bad battery.

There are other situations in which one might need to isolate one of the batteries from the electrical power distribution. For example, if one of the battery has been removed due to damage.

Switches with OFF-1-BOTH-2 connection arrangements like the BEP 701S are more flexible than the Blue Sea Systems switches (like the 5511e) that are being proposed as alternatives. With a Blue Sea Systems OFF-ON-COMBINE switch, a bad battery cannot be isolated. The remedy for that situation will be to temporarily disconnect the bad battery and carefully insulate the battery cable positive lead against accidental contact with anything else. This lack of flexibility is a significant drawback to the Blue Sea Systems OFF-ON-COMBINE switches which are being touted here.

The BEP battery distribution system with three switches which is intended for use in power distribution schemes were there is isolation between HOUSE loads and START loads is also more flexible than the Blue Sea Systems OFF-ON-COMBINE switch.

In designing electrical power distribution controls there are many possibilities. There is not a single design which fits all situations. As I began my comments, I will again observe that the BEP model 714 compact battery switch with dual sense VSR seems like a good design for application in a small boat because of its compact size and extremely simple installation.

jimh posted 05-30-2011 03:14 PM ET (US)     Profile for jimh  Send Email to jimh     
Re my so-called "pedantic" moderation: I suppose you could call using the proper spelling for important key words in discussions to be pedantic, but I just call it useful information. Information content is the most important goal for CONTINUOUSWAVE. We will leave bad spelling, bad grammar, bad capitalization, and bad information content for other websites to take full advantage.
jharrell posted 05-30-2011 06:01 PM ET (US)     Profile for jharrell    
It is true that in the rare event of a cell short while on the water the BEP will allow one to isolate the bad battery, where as with the Blue Sea one would need to pull out a wrench and disconnect the leads fro the bad battery.

Unfortunately to gain this flexibility for a relatively uncommon occurrence one does not get the ability to isolate the house from the starting circuit, leaving one battery completely unused running all devices off only the starting battery. To have a true house circuit one must go with the 716 which also lacks the 714's ability to isolate a bad battery.

Jefecinco posted 05-30-2011 07:31 PM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     
Except for larger boats with unusual power needs a dedicated "house" battery is a pretty unusual requirement. That is probably why the 714-100A is now being marketed.

For me a redundant battery is for back up in case the primary battery fails or otherwise has insufficient power to start my single engine.

Even when I had a cabin boat with an I/O V8 for power and heavier electrical loads redundancy was the purpose of the second battery.

I like what I'm reading about this new BEP product. You do not appear to be enamored but that does not mean many others are not.

I believe there is a place for both BEP and Blue Seas and the market place appears to agree.


RobP posted 05-31-2011 07:14 AM ET (US)     Profile for RobP  Send Email to RobP     
I have been looking at installing one of the VSR on our 2009 Boston Whaler 220 Outrage.

It came with a Blue Seas 6011 switch wired so that both the house and engine runs off of and charges the starboard battery while in the "ON" position. According to the Owners Manual you put it into the "Combine" position only if the starboard battery does not have enough charge to start the motor. The problem I have is the port battery does not charge unless you have the switch on the Combine setting.

I was thinking about the set up shown in the site, it uses the larger (but similar) Blue Seas OFF-ON-COMBINE switch and the BEP VSR that a lot of people (including VOC) recommend. Not to fire up the debate again but is this the best of both setup (Blue-sea vs BEP)?

bluewaterpirate posted 05-31-2011 08:08 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
I've installed 30 + of these two items. I prefer the BEP system because you can isolate the batteries. My install ratio is about 70 to 30 % in favor of the BEP systems. Both work as advertised. I've had a BEP 716 on my Whaler for over 5 years and it's never missed a beat. Two%20of%20a%20Kind%20Electronic%20and%20Fishing%20Upgrades/6-1. jpg?t=1306843587 Two%20of%20a%20Kind%20Electronic%20and%20Fishing%20Upgrades/11-1. jpg?t=1306843639


jharrell posted 05-31-2011 10:13 AM ET (US)     Profile for jharrell    
I don't think a dedicated house circuit is unusual if you already have a second battery in the boat. In fact it seems rather unusual to me to have a second battery sit unused only there in case of emergency starting.

I wanted a dedicated house circuit on my Montauk so I could run the electronics/lights on my boat without worrying about discharging the starting battery. Probably one of the more common occurrences of starting problems.

The BEP 714 kit would still protect against this situation but one would have to manually switch over to the unused battery and hope it is still good and the VSR has been keeping it charged. With the Blue Sea setup it is fully hands off and since both batteries are regularly used, you know if they are in proper working order.

As far as combining the Blue Sea 5511e switch with the BEP VSR, there should be no problem doing so. In my opinion the Blue Sea ACR is superior to the BEP VSR, is has more advanced hysteresis to prevent chatter, extra optional leads for remote status led and ignition disconnect and seems more physically robust from my inspection of both. But I only have experience actually using the Blue Sea, it would interesting to hear what advantages either has from someone who has experience with both.


You mentioned you like the BEP because of the ability to isolate a battery, but from what I can tell the 716 does not have this ability, it seems to function just like the Blue Sea switch? Looking at their wiring diagram, I guess you could reverse the leads and perhaps rewire the VSR to make the emergency parallel tie bars go on the load side instead of battery side?

Jefecinco posted 05-31-2011 11:03 AM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     

I find it interesting that you have a dedicated battery for the house loads on a little Montauk. But it's your boat so good for you. Perhaps if I used my boat for all night fishing at anchor while using electric down riggers and blasting the waters with highly amped music I too would desire a dedicated house battery.

I kind of like redundancy. I have a second anchor and rode stored in the RPS which has never been used. I don't see any reason to use it if I don't need to. I do like to use the redundant battery every few weeks just because I'm [especially careful] and I want to "really know" it's up to par.

I can't wait for the rebuttal.


bluewaterpirate posted 05-31-2011 11:34 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
As to isolating the batteries with the BEP 716. In the event my start battery goes bad I would turn the Emergency Parallel Switch to the ON position turn the start batery to OFF and switch the house battery to ON.

I can also place my Emergency Parallel switch to ON and place both my start/house batteries to ON. In this configuration I can use both batteries to start my motor if the need ever arises.

I can monitor the the condition of my house battery one of two ways:

1. Using an external battery monitor or

2. Using one of my two chartplotters or my FF. I have power readouts that reflect just the house battery. Pretty simple.

I've never had to replace any of these devices I've installed for clients (Blue Sea Systems or BEP). My BEP is put to the test everytime I boat running to and from the fishing grounds offshore NC.

To me neither is superior--they both work as advertised under less than good conditions.

jharrell posted 05-31-2011 06:26 PM ET (US)     Profile for jharrell    

So given the choice between two single switch solutions that cost nearly the same, I choose the one that does allow a true house circuit, and this is considered [obsessive behavior]?

Or is it [obsessive behavior] to have a second battery at all in my lowly Montauk?


From the wiring diagram of the BEP 716 it looks like turning off the starting switch and turning on emergency parallel would simply combine batteries for the house loads? Their diagram show batteries tied to the same lugs as the emergency parallel tie bars. Did you reverse the leads from their diagram and then move around the VSR leads to compensate?

This is the diagram I am talking about:

Jefecinco posted 05-31-2011 07:47 PM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     

Please brush up on your reading skills. My post said nothing about you being [obsessively behaved]. It did say that I am [especially careful]. I don't think I said anything to infer that a Montauk is "lowly". I believe the word I used was "small". Matter of fact, my boat is a Montauk which is a step up from my previous little Dauntless 16 which also had dual AGM batteries.

Like I said, it's your boat and if you want to rig the electrical system in a particular way you should do so and good for you. That does not mean your opinion is any better than my opinion or anyone's opinion. Your boat--your way!!

Good luck.


jimh posted 05-31-2011 08:44 PM ET (US)     Profile for jimh  Send Email to jimh     
There is some value in isolating the HOUSE and START loads, even on a small boat, because of the nature of modern electronic devices to be sensitive to voltage sags or voltage transients. Modern marine electronic devices vary in their tolerance to fluctuation in their supply voltage; some are rather sensitive. If the electronics don't like voltage sags or voltage transients, they will often blank out and need to be restarted. The restart can take too much time, particularly in the case of a position locating device like a GPS receiver, which might take a minute or two--or longer--to re-establish solid position information. To this end, isolation of the HOUSE and START loads is a good feature for a boat electrical system.

It is somewhat ironic, however, that the use of automatic combining relays or voltage sensitive relays to create automatic charging of the off-line battery (usually the HOUSE battery) can lead to a defeat of the principal purpose of the isolation of HOUSE and START. If the voltage of the START battery is quite high, it may cause the ACR or VSR to parallel the HOUSE battery to the START battery even when the engine is not running. Then, on engine start, the electronic devices on the HOUSE circuit may be affected because their battery is still in parallel with the START battery.

Blue Sea Systems recognized this problem and provides a circuit to prevent it from happening. But adding this circuit add complexity to the system. As we have seen from jharrell, many people do not connect this added circuit. As a result, they lose one of the most important benefits of isolation of the HOUSE and START loads.

bluewaterpirate posted 06-01-2011 08:34 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
Here you go ...... 4892322_2160096_31023115_WebLarge_4/ Image-4892322-31023115-3-WebLarge_0_d24fdc94f039163c83cd8cad988a7611_1 4892322_2160096_31023107_WebLarge_4/ Image-4892322-31023107-3-WebLarge_0_215779539cb5dd7522225e92edb49d6f_1

To it's prudent to have a dedicated start and house battery especially if you already have have two batteries.


bluewaterpirate posted 06-01-2011 08:36 AM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
Second link is bad. 4892322_2160096_31023107_WebLarge_4/ Image-4892322-31023107-3-WebLarge_0_215779539cb5dd7522225e92edb49d6f_1


jharrell posted 06-01-2011 12:04 PM ET (US)     Profile for jharrell    

Again unless I am missing something, the emergency parallel is tied directly to the battery terminals A & C, this would make it impossible to isolate a bad battery and then use the emergency parallel switch to tie the good battery in.

You said: "As to isolating the batteries with the BEP 716. In the event my start battery goes bad I would turn the Emergency Parallel Switch to the ON position turn the start batery to OFF and switch the house battery to ON."

Again this would simply parallel the batteries and turn off the starting circuit, leaving the house circuit running off both batteries, no isolation at all.

jharrell posted 06-01-2011 12:23 PM ET (US)     Profile for jharrell    
One other thing I noticed on the BEP 716 is that it does not come with the dual-sense relay whereas the 714 does.
bluewaterpirate posted 06-01-2011 12:59 PM ET (US)     Profile for bluewaterpirate  Send Email to bluewaterpirate     
Funny how we got this far ....... the 714 is a newer product, with that said I've got 5 + years of flawless use out the 716 funny haven't had a single battery issue. Next time on the water I'll do a video for ya.

jharrell posted 06-01-2011 05:12 PM ET (US)     Profile for jharrell    
I am not questioning the reliability of the BEP cluster. I was just curious as to how the 716 allows battery isolation, I honestly didn't think it could, and the pictures and schematics confirm that, however you say it can isolate batteries, I am interested in how it accomplishes this.
jimh posted 06-01-2011 05:24 PM ET (US)     Profile for jimh  Send Email to jimh     
The BEP model 714 is a compact and simple device that will be a good choice for a small boat. Its installation is no more complex than a standard battery switch, and it provides automatic battery charging management. I have no idea how this topic became so controversial.

As I have now said perhaps three or four times in this thread, you can turn the design of your primary power distribution system and your battery charging management into a more complex system, if you want, but adding complexity and features does not take away from the BEP model 714's primary attractions: simple, compact, and a good choice for a small boat.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.