Fried 8D Battery

[solanderi]

On our 1985 45C
I noted that on the starboard battery bank (12 system consisting of 4 x 8D's), one battery was warm but the second one was hot and the stickers on it were discolored from the obviously shorted battery. Last week, when servicing the batteries with distilled water, this same battery was significantly low on water. All 4 batteries were new 3 years ago.

So my action tonite was to turn off the oem Sentry battery charger. Do I need to turn off the battery isolation switches or any other action for safety reasons ?

I did read the threads about recommended replacement batteries and will probably call Interstate or the like tomorrow here in Miami. It may be time to finally bite the bullet and purchase a "smart " charger with a temperature sensor. I'll check out the Charles Line and would consider any recommendations. Thank you for any help.


Greg

 

[Trojan]

Disconnect all the batteries in the group asap. Get your meter out and measure the voltage on each battery. The boiled battery is most likely shot and may show dead, If the other batteries check OK on the meter and they probably won't. They should check low.Try charging each one by its self and see if they will hold a charge. If they hold a charge the battery is most likely good. If the boiled battery is shorted it will prevent the other batteries from charging and ruin them.

Bill

 

[solanderi]

Thank you. Will do. Actually the battery charger is a Raritan Crown 2 Automatic Marine Converter. It looks old. Anyone with an opinion about this equipment ?

 

[Trojan]

Old does not make it bad. But any time you have 4 batteries in parallel and one is shorted it's going to try like hell to bring that shorted battery up up 13.5 volts and the other batteries are going to suffer from an over charge. It's going to just keep pushing voltage into the bad battery.



BILL

 

[q240z]

I have a Magnum 2012 inverter charger on my 12v bank (eight 6v golf carts). You sometimes see them on ebay for extremely cheap. I paid $400 for one from an RV outfitter that was going belly up. Even with heavy use each summer, the entire battery bank is healthy, and that includes three batteries date stamped 2003. I highly recommend upgrading to a smart charger. With the Magnum, you need a remote panel to be able to equalize and do other fancy stuff. Still, given the cost of batteries it's a wise investment.

 

[Mike36c]

Check the specific gravity of each cell in each battery, it's cheap, easy and eliminates the guessing game.

 

[Pascal]

Ideally batteries in a bank should always be replaced together. If they are fairly recent (1 to 2 years) you can replace just one but at 3 years old you are probably better off replacing the bank

 

[REBrueckner]

All advice above; 3 years is not that long for a wet cell lead acid battery...could be a battery problem or a charger problem or (gulp) both....most likely a battery gone bad, it happens.

After replacing the battery(s), when all loads are off and the battery(s) in a static stable state, check the voltage from the charger to the battery several different and separate times and make sure it is within manufacturer spec.

 

[solanderi]

Thank you all.
The way I understand my system, 1985 45C 12v with 4 x 8d where one bank of batteries (2 of the 8D's) are "house" batteries while the other side are the batteries that are for starting the motors. Does that sound right ? In my case it is the Starboard, stern most battery that got cooked. It is piggy-backed to another starboard 8D.

Is there a down side to to using the acid glass mat batteries for all four positions ? Are they REALLY maintanance-free ?

Thank you for any help.

Greg

 

[REBrueckner]

AGM's are potentially very useful for deep discharge use. Downside: they are a lot more expensive and offer little advantage I can figure for start applications. They also require their own charge setting on battery chargers.

 

[rsmith]

I thought AGM's would be great but I've had a lot of problems with them in my cars and trucks.Even with the correct charger they are very hard to get fully recharged. I had a problem with one the in my truck and my whaler where they would bleed down if not run for a week. And then you cant just jump it and let the alt charge it up you need to put it on a charger to top it off. Google "AGM problems" and you will see.

 

[solanderi]

Follow - up

After considering all of the options, I ended up replacing all 4 batteries with essentially what I had previously, 4 flooded 8D's. The price I got on the AGM's (Glass Mat) was 545 per battery, which is double the price of the flooded batteries and would have required me to change out the charger at the same time. I still have the charger upgrade on my list but I can shop it and buy it at my convenience. Its hard to change out the flooded battery technology that have served me without a hiccup for a technology that introduces a shred of doubt. IMHO.

Thank you to all that contributed.

Greg

 

[REBrueckner]

"I thought AGM's would be great but I've had a lot of problems with them in my cars and trucks.."

Do the regulators have an "AGM" setting...or are they fixed set for wet cell batteries???