Replace Battery Switch

Electrical and electronic topics for small boats
padrefigure
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Joined: Sun Oct 18, 2015 9:26 pm
Location: Texas, Hill Country

Replace Battery Switch

Postby padrefigure » Mon Apr 25, 2022 3:01 pm

I plan to upgrade the electrical system on my Outrage 18. It currently has [a mechanical battery switch that has positions] OFF 1-BOTH-2 selector for two batteries. I believe there is oxidation in the contacts causing a poor conductive path.

When I did this on another project boat, I installed a Blue Sea Systems ACR (Automatic Combinrt Relay) and selector switch. I do not recall the exact model numbers.

Given advancements in technology, do you think [a selector switch and ACR] is still the preferred system to use on an outboard powered boat with minimal house loads?

If not, please offer suggestions on alternate systems.

jimh
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Re: Replace Battery Switch

Postby jimh » Mon Apr 25, 2022 4:08 pm

See prior discussions at

Dual-circuit Battery Switches
https://continuouswave.com/forum/viewto ... Acr#p14966

and

BLUE SEA SYSTEMS Automatic Combiner Relay
https://continuouswave.com/forum/viewto ... ?f=9&t=912


For a boat with two batteries, the traditional switch used to connect the batteries to the engine has been a specialized switch with positions OFF-1-BOTH-2. This switch has only one output circuit, and it simply selects which battery--NONE, Battery 1, BOTH Batteries, or Battery 2--will be connected to the engine and to all other electrical loads in the boat

For boats with modern electronics and other non-engine-starting loads, a more common and perhaps more useful arrangement is to have a switch that has two poles; one pole handles the engine and the second pole handles all other non-engine loads, usually called the HOUSE loads. A switch of that type is made by BLUE SEA SYSTEMS and is called the e-Series Dual Circuit Plus Battery Switch. See

https://www.bluesea.com/products/5511e/ ... ery_Switch

These battery switches have only three positions: OFF--ON--COMBINE BATTERIES.

The COMBINE BATTERIES is generally never uses unless there is a problem with the engine cranking battery, and the cranking battery alone cannot start the engine. The second battery or HOUSE batter is put in parallel for the engine starting.

Keeping the HOUSE loads--mainly electronics--separate from the engine cranking helps to keep voltage sags or transients out of the electronics.

I use a Model 5511e switch on my boat. I have never had to use the COMBINE BATTERIES position to get an engine start.

jimh
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Location: Michigan, Lower Peninsula
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Re: Replace Battery Switch

Postby jimh » Mon Apr 25, 2022 4:40 pm

If a two-pole switch is used, the engine battery charging output will not be charging the HOUSE battery. There are two solutions:
  • if available, equip the engine with an auxiliary battery charging cable that provides a second, isolated battery charging output and connect that output to the HOUSE battery, or
  • use an automatic combiner relay to parallel the batteries when the starting battery has been fully recharged.

If available from the engine, the second battery charging output is a much preferred solution. It will be simpler, and the HOUSE loads will never be in parallel with the engine cranking load as long as the battery switch is not put in the COMBINE BATTERY position.

If the engine does not have the option for a second isolated charging output, the ACR is the only solution to charge the HOUSE battery from the engine. The drawbacks are a much more complicated installation, and whenever the ACR relay is closed, the HOUSE loads will be running off the combined batteries, so the engine cranking could generate sags or transients into the HOUSE power distribution.

jimh
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Location: Michigan, Lower Peninsula
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Re: Replace Battery Switch

Postby jimh » Tue Apr 26, 2022 10:11 am

If planning to install an ACR please see this article on the Blue Sea Systems 7610 Combiner so that you can understand the total cost of the installation:

Blue Seas 7610 Automatic Combiner [Most recent update]
https://continuouswave.com/forum/viewto ... 357#p41357

The typical "kit" or bundle sold by BLUE SEA SYSTEMS omits many additional components necessary to perform a proper installation, such as added wiring, fuses, switches, LED indicators, terminal strips, ring connectors, and so on.