Engine Cranking Battery

[jimh]

WHAT TO BUY

I am in the market for a new cranking battery to start my 225-HP outboard engine. The engine specifications call for a battery with a rating of 1,000-MCA. For several years the engine cranking battery on my boat was an INTERSTATE BATTERY model 24M-XHD. See the specifications at

http://www.interstatebatteries.com/p/interstate-batteries/interstate-batteries-24m-xhd-24m-xhd

The INTERSTATE 24M-XHD can deliver 1,000-Amperes of cranking at the usual marine rating of 32-degrees-F (the "marine cranking Ampere or MCA rating.) That is a very substantial amount of cranking Amperes, and just about any outboard engine should be able to be cranked over and started with this battery. The 24M-XHD is a BCI case size Group 24, so it fits in practically any battery box, including the classic Desert Tan Boston Whaler OEM battery boxes. One of the more outstanding features of the INTERSTATE 24M-XHD is the price: only $118 at retail from an Interstate store or dealer. In these days of 12-Volt batteries that cost $250 to $400, the 24M-XHD looks like a bargain.

The 24M-XHD is a classic lead-acid, vented, flooded-cell battery. There should not be any problems charging this battery from an outboard engine with the usual simple charging output with only voltage regulation. The only disadvantage of vented batteries is the electrolyte level may become low, either due to evaporation or perhaps from over-charging, but cells can be easily refilled with distilled water to replace any lost electrolyte.

If you want to avoid having to worry about checking the electrolyte level, a sealed battery will eliminate that chore. In the INTERSTATE line there are sealed batteries with absorbed glass mat (AGM) construction that have a rating of 1,000-Amperes of cranking. The model 34M-AGM battery is rated for 1,000-Amperes. See the specifications at

http://www.interstatebatteries.com/p/interstate-batteries/interstate-batteries-34m-agm-34m-agm?dsNav=N~4165663998-2147384903

The AGM construction comes at a price; this battery retails for $300. That is almost three times the price of the 24M-XHD.

For the last six years my outboard engine has been getting cranked over by a SEARS DIEHARD PREMIUM MARINE battery, a very nicely rated AGM battery that used to sell for about $220 and was often on-sale at a reduced price, sometimes as low as $180. This battery was widely believed to be a private-label version of the ODYSSEY AGM battery, which sold for a higher price. Unfortunately, it appears that the arrangement SEARS had with ODYSSEY to sell their AGM battery at a substantially lower price must have ended, and SEARS no longer offers that product.

I believe the equivalent product from ODYSSEY is labeled as their 34M-1500 battery. That battery is rated for 1,050-Amperes. The specification can be found at

http://www.odysseybattery.com/marine_battery_specs.aspx

The ODYSSEY 34M-1500 has a retail price of $302. (See http://shop.odysseybattery.com/p/34m-pc1500st) This model has dual terminals; it has the usual automotive posts, and it has 3/8-inch positive and 5/16-inch negative threaded SS stud terminals.

If you don't need the dual terminals, there is a less expensive version with only the automotive type posts, the 34-PC1500T that sells for $276. If your boat is rigged with conductors for terminal posts--as mine is--the extra $26 for the marine version will be a good investment.

Both the ODYSSEY batteries are BCI Group 34, which will fit in a standard battery box, but the battery is not as tall. To compensate you can buy a plastic riser plate for $4. See http://shop.odysseybattery.com/p/spacer-for-group-34-batteries?referring_products=%7Cdfaf9aed24f729642a834e76f380e305

WHERE TO BUY

Distribution of INTERSTATE flooded cell batteries is a bit of a problem because they cannot be shipped. You have to go to a dealer and buy the battery. Presumably INTERSTATE delivers the batteries to their dealers on their own trucks, as I doubt you can ship a flooded cell battery with electrolyte in the cells by any common carrier. Finding a dealer can be a problem, particularly for a marine battery. Generally the INTERSTATE marine batteries are sold at marine stores--that's where I first found out about the 24M-XHD, at my own marine dealer. They are also sold through many automotive shops, but I suspect it might be hard to get a marine battery from a place like Midas Muffler, an INTERSTATE dealer.

I recently discovered that INTERSTATE has their own retail store in my area, just a short distance away, and I can walk in and buy the 24M-XHD battery from them at the retail price and during some promotion periods, like during parts of Spring when boaters are fitting out, at an even lower price.

ODYSSEY sells their batteries on their shopping website. The prices include free shipping in most instances. This is one of the great advantages of the AGM construction: the vendor can ship the battery to you. The shopping site includes a possibility to enter promotion codes, so there might be a promotion or discount available at some times. ODYSSEY batteries are also sold by dealers with retail stores, like BATTERIES+BULBS.

Curiously, I just tried to find the ODYSSEY 34M-1500 at BATTERIES+BULBS. In that search I came across their house-branded X2 battery, model SLI34AGMDPM. The specifications and appearance are quite similar to the ODYSSEY or SEARS batteries, and the price is more attractive, about $235, or around the price that the SEARS version was selling at when not on promotion. Compare at

https://www.batteriesplus.com/battery/marine-and-boat/starting/bci-group-34m/sli34agmdpm

The specifications only give cold-cranking Amperes (at 0-degree-F or CCA rating), but with 880-CCA that is generally the equivalent of 1,000-MCA.

BATTERIES+BULBS does sell the OYDESSY 34M-1500ST battery, but their price is a bit higher, $346 retail. See

https://www.batteriesplus.com/battery/marine-and-boat/starting/bci-group-34m/heppc1500mst

MY NEXT BATTERY

This spring on my boat the SEARS-ODYSSEY battery will on its eight season of use, and I will probably demote it to the house battery, and look for a new battery for engine starting. Right now the first-place candidate is the INTERSTATE 24M-XHD. I like the price. Because of its location in my boat, to check electrolyte level and add distilled water is not very difficult, so I don't see a problem with the flooded-cell vented design. Now that I have found a dealer just a few miles away, I can easily get this battery. (My marine dealer that sold me the original one about ten years ago no longer carries INTERSTATE.)

Next in line would be that house-brand X2 version of the ODYSSEY. It is about double the price of the flooded-cell battery, but I may talk myself into spending more to stay with the sealed AGM construction.

If readers have any alternative suggestions for a good quality, good price cranking battery rated at 1,000-MCA, please mention your choice in a reply to this thread.

[Tom Hemphill]

If you can't easily get the Interstate battery you describe, based on personal experience I recommend NAPA Auto Parts 8304 Marine Starting Battery -- Group 24M 800 CCA (1000 MCA), currently offered for $108.

[RichS]

I purchased two Exide Edge FP-AGM24DP AGM batteries for my 1988 Outrage 18 with a new Suzuki 140 and paid $150 each (free shipping) from LM Fleet Supply. I see they are out of stock now, but they are available from others for a little more. Rural King has what I believe is the same battery with their own label for $130 in store only. They are dual purpose, so they can be deep-cycled. The trade-off is that they have a little lower MCA rating of 930-Amperes.

I haven't installed them yet so can't comment on performance, but they do get good reviews. They'll be installed with a Blue Sea Add-A-Battery kit.

[porthole]

My local Costco carries Interstate. My curiosity will have me check to see what they have in marine battery choices.

So Jim, are you to run a new battery along with an 8 year old battery on the same charging system?

[jimh]

ASIDE to PORT' on the sidebar topic of having batteries of different types or ages in the primary power system of a boat:

I don't worry about mixing two batteries of different age. The boat's outboard engine (2010 E-TEC 225) has two charging outputs, main and auxiliary, and the boat's two batteries are not wired in parallel, except in an emergency to start the engine. (I gave more details on the primary power distribution wiring, battery charger wiring, and fuse and circuit breakers in an earlier article.)

The outboard engine on my boat is typical of outboard engines: its battery charging output is just regulated to a particular voltage, and the engine tries to maintain that voltage at the charging output. The amount of current that will flow is determined by the load on the charging output, that is, by the battery, its state of charge, and its ability to accept charging current. Each output has roughly 25-Amperes of current available.

The HOUSE battery on my boat for the last four years has been a big 78-Ampere-hour AGM battery. That battery was probably four-years-old when I put it on the boat. It came out of a big uninterruptible power supply (UPS) that had 40 batteries (in series). When we are on a cruise we might be seven to ten days without shore power. I want to be sure the engine can start in the morning.

[jimh]

I purchased two Exide Edge FP-AGM24DP AGM batteries for...$150 each (free shipping) from LM Fleet Supply.

I see the Exide Edge FP-AGM24DP Flat Plate AGM Sealed Marine Battery on Amazon at $205

https://www.amazon.com/Exide-FP-AGM24DP-Sealed-Marine-Battery/dp/B00HAIGJF0

At $150 they'd be quite attractively priced.

[jimh]

...based on personal experience I recommend NAPA Auto Parts 8304 Marine Starting Battery -- Group 24M 800 CCA (1000 MCA), currently offered for $108.

That looks like a nice option. Here is the link to the on-line store:

https://www.napaonline.com/p/NBD8304

[jimh]

Generally the price of the battery is quoted without the "core charge" or the deposit you pay for the lead in the battery to encourage you to recycle it. Some retailers have a core charge of $18. I usually keep at least one extra lead-acid battery around so I can use it as the "core charge" exchange core. I remember when the core charge was $4.

If you buy a battery on-line and have it shipped to you, I don't think you can avoid the core charge; it must be built into the battery price. You really can't exchange an old core for a new one if buying on-line and receiving the new battery by direct shipment. That extra cost--perhaps $18 now--is a consideration for buying the battery at an actual brick-and-mortar store, or at least to pick-up the battery at a real store and exchange the core with them.