Starting battery for genset.

My Generator Starting battery died. It was a CAT Maint free 5760.

I'm looking to replace and need some rudder.

Generator is a 8.5 Westerbeke

Want a wet battery Maint free and a starter battery.

Recommendations? Size? CCA?

Figure out the case size ( car 24, 27 ,31 ----,4D, 8D ) whatever and go to sears.

Should be about $100 if its car sized

Hmmm. . . . Seems like this topic was just recently discussed on another thread??

As I recall the point was, it doesn't take much to start a small generator. Just about any full sized car battery will do. A good suggestion which I agree with was, to put in a larger starting battery that also could be used in an emergency to start your main engines, if you have the space?

I had the space, took out the smaller battery and put an Interstate wet 4D which is now my backup for starting the mains.

Just about any of the major brand batteries will give you good service. I've used many different brands with good success. However, I've standardized all my batteries on Interstate only because of availability, price and excellent performance. I get a bulk discount and they deliver. In the boat I use Interstate Batteries 4D wets and cycle them out at seven years. Even after I cycle them out, I bring them back to the shop and as long as they're kept up, will usually last another 3 or 4 years in other equipment. I hope I am answering your question.

IMHO
Larry B

Have a 20 year old 8kw Westerbeke and a regular old Group 24 starting battery spins her up fine.

Best I can determine from the complicated conversions between amp hrs and CCAs and what American Diesel told me...a decent Group 24 should be fine for a Lehman also...I find it hard to justify going that small...but that's as near as I can figure.

I am too new to know if this a useful suggestion, but I figure it couldn't hurt and if it isn't helpful then you can ignore me easily enough.

I have had a lot of success over the years, in high stress application, with Optima batteries.

They run from the low one hundred dollar range to the high two hundreds.

The main advantage they have is that instead of flat plates in a single enclosure they use spiral wound wires in an individual cell. They actually look sort of like a "six pack".

I've used them in drag cars pulling up to 2g's (more impressive than it sounds) and off-road vehicles that duplicate the effect of a moderately enthusiastic brawl in a standard military drinking establishment.

I am ASSUMING that this would imply good durability in marine conditions.

Here's what one looks like. Hope you find the info useful:

I use a group 27 12v I bought at WalMart for $65 about 4 years ago. So far so good...no problems starting my 8kW Kohler.

It is probably a group 57 battery. You could get one at most auto supply stores, NAPA, Carquest, etc. Take your old one with you just to be sure, plus you will need to turn in a old one for the exchange.

Edelweiss, I started the prior thread. Onan specified a 150 ah battery for my Onan 6.5 genset. Seemed huge for a little 3cyl diesel (?Kubota) but I did it anyway, the new one is 1150CCA, unsurprisingly it pre heats and starts impressively. It also has its own 25w solar panel, with regulator to keep it fit and healthy.

All, thank you for the great info. Psneeld, I was thinking along your lines and appreciate the info.

As for the prior thread, it was more about amperage and alternators then a segment on Starting battery for a genset. If my question offended anyone (Edelweiss..) or seemed like I was ignorant to a prior thread that was similar but not really, mea culpa.

Batteries Plus - Some 500++ Stores – “Xtreme” wet cell batteries... manufactured by East Penn Co. http://www.dekabatteries.com/ . Much battery equipment... reasonable prices and good service! I always use wet cell and make sure "sealed" batts still have way to check and fill w/ distilled water. Keep em filled and they keep on chugging!

BTW, just for S&G, thought I might mention – I’ve a 1999 NAPA 27 batt still starting my 7.5 kw Koehler gasser just fine. Batt is sulfating on + terminal after 14 yrs service, but, plenty power still. Guess I should change – however it is fun to see just how long she'll stay alive! I keep a new 27 isolated and fully charged on board at all times! Just in case - LOL

Good Luck - Art

BruceK said:

Edelweiss, I started the prior thread. Onan specified a 150 ah battery for my Onan 6.5 genset. Seemed huge for a little 3cyl diesel (?Kubota) but I did it anyway, the new one is 1150CCA, unsurprisingly it pre heats and starts impressively. It also has its own 25w solar panel, with regulator to keep it fit and healthy.

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Bruce, I'm surprised Onan specified a 150ah battery for your 6.5 unit. As luck would have it I have just replaced my Onan gen battery today. I have a 7KW model and the specs show a minimum CCA rating of 360amps. I went for a 100amp(CCA 720amp) to be on the safe side. Your 1150 CCA battery would give your 6.5kw generator the shock of its life.

Andy G said:

Bruce, I'm surprised Onan specified a 150ah battery .. .Your 1150 CCA battery would give your 6.5kw generator the shock of its life.

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Andy,the Onan has accepted its new friend and is no longer "spilling its seed". The old battery had similar dimensions, maybe CCA increased with technology. It is overkill, but is Onan specified, and the original IG battery box is the right size. It would start the Lehmans no sweat, so is good back up. Some PO had it running the 12v fridge, not so good if you flattened it and needed the genset, though the beer would be cold.
Art, that battery maker might give you free one if you tell them how long it has lasted. Amazing performance.

AH is frequently a measure of the battery ability to discharge slowly over time , as used to compare deep cycle batts.Usually at a 20hour (till dead ) rate.

CCA or the bogus MCCA is cold cranking amps , the real measure of a battery used to start engines.

Almost every car engine will have the CCA to start a noisemaker just fine.

Art said:

Batteries Plus - Some 500++ Stores – “Xtreme” wet cell batteries... manufactured by East Penn Co. http://www.dekabatteries.com/ . Much battery equipment... reasonable prices and good service! I always use wet cell and make sure "sealed" batts still have way to check and fill w/ distilled water. Keep em filled and they keep on chugging!

BTW, just for S&G, thought I might mention – I’ve a 1999 NAPA 27 batt still starting my 7.5 kw Koehler gasser just fine. Batt is sulfating on + terminal after 14 yrs service, but, plenty power still. Guess I should change – however it is fun to see just how long she'll stay alive! I keep a new 27 isolated and fully charged on board at all times! Just in case - LOL

Good Luck - Art

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Thanks Art. Always good info.

FF said:

CCA or the bogus MCCA is cold cranking amps , the real measure of a battery used to start engines.

Almost every car battery will have the CCA to start a noisemaker just fine.

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All of this discussion about CCA gets me laughing.:lol:

Does anybody remember the Sears Die-hard battery commercials done during the winter in International Falls, Minnesota? That is where CCA makes a difference - When it's too cold for the chemical reaction in a battery to produce electricity.

Boating during times when CCA counts is a bit dificult, as the water is way too solid - don't need a boat, we just drive a truck across the water.

Anytime a battery is above +20degF, CCA does not much matter. When the temperature is -10degF or colder, we keep a spare battery available in the heated garage for jumping vehicles parked outside. It is also extremely important to keep the batteries charged, otherwise they will freeze, wreck the plates and crack the case.

theran5317 said:

All of this discussion about CCA gets me laughing.:lol: Does anybody remember the Sears Die-hard battery commercials done during the winter in International Falls, Minnesota? That is where CCA makes a difference - When it's too cold for the chemical reaction in a battery to produce electricity. Boating during times when CCA counts is a bit dificult, as the water is way too solid - don't need a boat, we just drive a truck across the water. Anytime a battery is above +20degF, CCA does not much matter. When the temperature is -10degF or colder, we keep a spare battery available in the heated garage for jumping vehicles parked outside. It is also extremely important to keep the batteries charged, otherwise they will freeze, wreck the plates and crack the case.

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Theran, it is an industry accepted standard. It has nothing to do with the conditions the battery will be used it.

BUT...I would like to recommend the Sears Die Hard Marine Group 31 AGM...which, coincidently, has 1150 CCAs. Not cheap...but made by Odyssey which is considered one of the best batteries on the planet.

Baker said:

Theran, it is an industry accepted standard. It has nothing to do with the conditions the battery will be used it..

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CCA, is an automotive industry standard test SAE J537, that measures how long a battery can sustain a measured current draw at either 0degF or -20degF, before dropping below 7.2volts. Something very important to those of us that live under these conditions.

Although CCA might useful for comparitive purpose, batteries in boats are kept at a much higher ambient temperatures, and will exhibit different characteristics under these much warmer conditions, and it is definitely only used for high current draw applications.

theran5317 said:

CCA, is an automotive industry standard test SAE J537, that measures how long a battery can sustain a measured current draw at either 0degF or -20degF, before dropping below 7.2volts. Something very important to those of us that live under these conditions.

Although CCA might useful for comparitive purpose, batteries in boats are kept at a much higher ambient temperatures, and will exhibit different characteristics under these much warmer conditions, and it is definitely only used for high current draw applications.

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It is probably better than boasting about the quality of the plastic in the casing of the battery??????
My point being(and that of the manufacturer as featured in that Die Hard commercial) is that if they can perform in those conditions well, then they will likely perform better in more favorable conditions. I don't believe it to be as arbitrary as you are suggesting....hence my plastic quality remark above....that really would be arbitrary....in case you missed my point up there.

Baker said:

I don't believe it to be as arbitrary as you are suggesting....hence my plastic quality remark above....that really would be arbitrary....in case you missed my point up there.

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And speaking of the quality of battery "plastic". . . . It's been a while since I bought a battery box. We used to toss them when they got gunked up with crud and oil. Maybe not anymore.

Just priced some 4d boxes, cheapest was $65 . . . up to $175. . . the cheapy was made of a hard plastic that wouldn't have lasted 2 minutes if a wrench was dropped on it.

I'll be breaking out the degreaser and Brillo pads.

A question. My battery box(solid fibreglass unit, came with the boat) is too big for the genset battery so I have book ended the battery with some polystyrene packing to keep it from moving.

Would this cause any potential issues?

As long as the batteries are secure and don't allow the terminals to short, you should be good-to-go.

I had the same situation with my mains. Boat had built in fiberglass double 8D sized box and I swapped the 8D's years ago for 4D batteries. I cut two blocks out of hardwood to take up the extra space and it's been that way for years, no problem.
LB

Andy G said:

A question. My battery box(solid fibreglass unit, came with the boat) is too big for the genset battery so I have book ended the battery with some polystyrene packing to keep it from moving.

Would this cause any potential issues?

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No.

Edelweiss said:

As long as the batteries are secure and don't allow the terminals to short, you should be good-to-go.

I had the same situation with my mains. Boat had built in fiberglass double 8D sized box and I swapped the 8D's years ago for 4D batteries. I cut two blocks out of hardwood to take up the extra space and it's been that way for years, no problem.
LB

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The P.O of my boat had a great idea, they made a rack out of wood to take up the extra space in the battery box that was built for 8d's that has a 4d in it... the wood was drilled to hold extra downrigger balls. The balls are heavy and can make a big mess if they get loose in the hull
HOLLYWOOD

Please explain why a single starting battery isn't sufficient for the main propulsion engines as well as the genset. It isn't obvious to me why the genset needs its own starting battery.

markpierce said:

It isn't obvious to me why the genset needs its own starting battery.

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It is ultimately a matter of redundancy. You want your generator battery fully isolated so if you run down all the rest of the batteries, you still have a battery to start the genset...and hence have the battery charger available.

markpierce said:

Please explain why a single starting battery isn't sufficient for the main propulsion engines as well as the genset. It isn't obvious to me why the genset needs its own starting battery.

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Redundant safety strategy! As in: If main propulsion’s battery fails there is gen set batt as back up - or vice versa!

Personally... I always carry a triple batt safety hedge aboard, i.e. main bank of four (4) deep cycle 31’s that also are used for propulsion starter batts / one (1) gen set 27 starter batt / one (1) isolated, never used and fully charged 27 batt (in black box hooked up to nothing, with its own low amp charger that activates when AC power is on). And, of course, I also have a 27 batt on our runabout that also might or might not go kabloeeee!

Sooo I feel confident that chance for unmanageable batt problems are very limited in our case while out and about!

PS: Did I mention the fully charged 31 deep cycle we always load and leave in SUV when we go to boat for fun-time!! LOL

So, you fellows believe at least three engines (not counting thrusters) and at least three, four, or more battery banks are needed to feel comfortably safe? Do you also have double hulls?

markpierce said:

So, you fellows believe at least three engines (not counting thrusters) and at least three, four, or more battery banks are needed to feel comfortably safe? Do you also have double hulls?

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Just douple/triple batt protection! Inexpensive safety - Try it... You'll like it!

BTW - Tolly hull is 3/4 to 1 1/4 inch thick FRP throughout its bottom. Could be called a double thick hull!

Have found two sets of batteries, a single engine (with anchor and towing insurance not yet required), as well as a steel hull, to be sufficient.

IF the weight and maint of multiple batterys are aboard the option of using them for multiple redundancy for the price of a switch or two makes good sense.

Of course this assumes the boat operator understands the setup.

YRMV