Dry battery

[sagablu]

Good day all,

So my issue: Had some problems cranking the engine (3GM30F) with the battery switch to "both". I have two FLA deep cycle Deka Marine batteries. I have 13.3V at the posts, they are being charged with a 50W panel controlled by a Victron 75/10 and a Xantrex ACR.


The problem it seems is one battery needs water, the plates are exposed. The other is low but the plates are covered. So my question, should I add the water now? I am concerned it may not mix well with the boat in the slip and may freeze. Would I be better off waiting until warmer weather to add water?


Appreciate the advice.

[Bill Seal]

A battery with exposed plates will probably sulfate and die.

[GrowleyMonster]

Cover the plates!!!!!!!!!!! Cover them and add more water (assuming full charge) until the level is just under the bottom of the fill/vent tube, maybe by 1/4" or according to the manufacturer, actually. You want to leave room for gassing to avoid burps. Now with the batteries at proper electrolyte level, either (preferably) equalize, or else just use them, with a nice big load like maybe 1/7 or so of rated AH capacity until the State Of Charge is down to around 60%, then recharge. You should get enough gassing to stir up the electrolyte. The sulfuric acid solution will have to get plenty cold before it freezes. 32f will not even come close to freezing a battery, just reduce its performance until warmer weather. With sub zero temps inside the boat, you might well be concerned. Most boats in the water do not get far below freezing point of water, down below. If you are really worried, take them home with you and keep in the basement on trickle charge, or out in the garage on a smart charger.


Honestly I don't know how cold a FLA battery has to get before it can freeze. I have never seen it happen and my old Subaru was out in the open in 13f temps while I was working offshore in the oil patch I think around New Years Eve 1989/1990, and Atchafalaya Bay and Vermillion Bay were sporting a nice sheet of ice. There were 14' icesicles hanging from Vermillion 141. Coldest I have ever seen in S Louisiana. When I went back to the car the freeze plugs were still in the block and the battery started the motor just fine. No cracks or bulges in the case. So a cheap starter battery up in the air can survive 13f temps. Below the waterline in your boat would need much colder weather to get that cold. Maybe some of those Yankees up there in the land of ice and snow can relate their experiences. Usually the coldest I get is when I stick my hand in the cooler for another icewater-cold PBR.

[john61ct]

Already damaged most likely.

Ideally refill, then Full charge via endAmps, then a heavy equalize session.

Resolve to treat them better, and the replacement bank, in future.

[Calif.Ted]

Add the water (distilled, I use a ketchup type squeeze bottle), if it's being charged probably can't freeze regardless. The battery is probably toast, when I can't start my 3gm30 on the one battery I've been using all day to keep beer cold and have to switch to both I know it's time for new batteries.
You may be able to get them to show full voltage but they won't stand up to a load and die quickly in use.

[Wotname]

Not related directly to the OP's question however if low battery charge is preventing starting with a 3GM30 engine (or any other engine with decompression levers), try decompressing all cylinders and spin the engine over with the starter motor. It will spin easily with an almost flat battery when decompressed. After a couple of seconds of spinning, drop the decompression lever on one cylinder, if that cylinder fires, then bring in the remaining cylinders (one at a time).

It will get you out of trouble!

[Bill Seal]

If your battery is toast and won't take a charge, in an emergency you can try charging it as much as you can, and then "crowbar" it (short it out) using heavy jumper cables, -or an old wrench you don't like- which may break up some of the sulfation. Do this several times and if you're lucky, the third time your cables will start smoking.

[Calif.Ted]

Originally Posted by Bill Seal

If your battery is toast and won't take a charge, in an emergency you can try charging it as much as you can, and then "crowbar" it (short it out) using heavy jumper cables, -or an old wrench you don't like- which may break up some of the sulfation. Do this several times and if you're lucky, the third time your cables will start smoking.

That must be exciting, I've used jumper cables and a 4D battery to weld fence posts in a pinch.

[sagablu]

Thanks all,

I will fill them and see what happens. I was planning when time allows to change the two batteries for one bank of two gold cart batteries and adding a third start battery. This incident may move this project ahead of re-bedding the stantions.

[JPA Cate]

Originally Posted by sagablu

Thanks all,

I will fill them and see what happens. I was planning when time allows to change the two batteries for one bank of two gold cart batteries and adding a third start battery. This incident may move this project ahead of re-bedding the stantions.

Nah, a dry boat is a happy boat. If the stanchion bases are leaking to below decks, do them first. Just add water and re-charge the batteries. Deal with them afterwards, when you can be dry below.

Ann

[Zil]

Jumping across a lead acid battery is disaster going to happen. Don't do it.