Killed my battery

[scottybm1]

So I haven't started my boat in months, went out today to see if it would and you know it, dead battery. It's a pretty new deep cycle 75 amp hour. My problem is that my big charger died and all I have now is a 1 amp motorcycle battery charger. The voltage on the battery now reads about 10.5. Will my little 1 amper put some juice back in it or do I need to spring for a new charger now rather than later?

 

[NYBo]

Re: Killed my battery

With voltage that low, the battery has probably been damaged. Throw the motorcycle charger on it if you can't get a new regular charger very soon. It will be better than nothing.

 

[scottybm1]

Re: Killed my battery

With voltage that low, the battery has probably been damaged. Throw the motorcycle charger on it if you can't get a new regular charger very soon. It will be better than nothing.

That's what I was afraid of. Guess I'll charge it and see. I have a gel-cell for my camper that I'll throw in there for now, I'm going to get another large charger and a couple of tenders so this doesn't happen again.

Thanks.
Scotty

 

[bassman284]

Re: Killed my battery

AS NYBo says, the battery is probably shot. In any case, the 1 amp charger isn't going to do anything. You need a 10 amp automatic charger, preferably 3 stage.

 

[Silvertip]

Re: Killed my battery

Be aware that it will probably take several days to charge that battery with a 1 amp unit.

 

[swl]

Re: Killed my battery

Also (someone correct me if im wrong) I dont think you are supposed to use gel cells for starting batteries.???

 

[fishin west]

Re: Killed my battery

You are correct gel cell batteries are usally glass mat, lending themselves to slow steady discharge at lower rates of amperage. Cold cranking amp's can be very high with starters for motors. Recharge times with the gel cells are usally similar to the discharge rate, slow and steady. When your voltage get's down that low on a 12 volt system it is a 50/50 proposition that the battery is still good. If you can get it charged back up, load banking the battery will tell you if it is good. I think most auto part's stores have battery load bank's.

 

[scottybm1]

Re: Killed my battery

Took it into work today and threw it on a bigger charger. Hit it on a 12 volt low for about 2 hours. After really stopped drawing any amperage, I took it off and popped the caps off of the cells. I used a hydrometer but the indicator for specific gravity didn't even read. I did put a load tester that we have on it, it connects to neg and pos and you pull a trigger. It heats a coil and you hold it for 15 seconds. It read green but the specific gravity test worries me. I think I'll be taking a spare battery with me for a while until I trust it or it fails completely. I'm a Coast Guard coxswain and have towed countless boats that had electrical failures caused by a dead battery. Aint gonna be me!
Thanks everyone.
Scotty

 

[scottybm1]

Re: Killed my battery

Also (someone correct me if im wrong) I dont think you are supposed to use gel cells for starting batteries.???

Aren't Optima red and yellow tops gel cells? Recommended for maximum performance!

 

[seabob4]

Re: Killed my battery

My recommendation. Install a good onboard charger. Guest, ProMariner, Charles, whatever. Wire the charger 120VAC input to a charger inlet. Get home? Plug it in. Leave it. Go back out? Unplug it, have good batts. Repeat the process. Your batts will thank you, as well as the wallet and the Admiral...

Keep in mind, if you have gel cels, you need to change the charge setting on the charger...AGMs and wet cells can charge at the same rates/voltages...

 

[Chris1956]

Re: Killed my battery

Scotty, Charging batteries slowly is good for them. A 1A charger is a bit on the slow charge side, but is fine for this use. Figure about 3 days to fully charge that battery. A fully charged battery should last a long time(6 months or more), as long as there is no short or parasitic drain on the battery.

I recommend you check for shorts in the electrical system. Put an ammeter in series with the Pos pole of the battery and the pos battery cable of the engine. Make sure you start with a 10A Ammeter, so you don't blow the meter, and work your way do read the exact drain (if any). Track it down and fix it.

Is it possible you left something (FF?) turned on for those months?

 

[bruceb58]

Re: Killed my battery

Scotty, Charging batteries slowly is good for them.

Its no better than charging them at 10A. You are actually better to get them back up to charge quicker than letting them sit longer at an undercharged condition. The 1 amp charger may also not go into float mode when it finally does get a full charge and will cook the water right out of your battery.

 

[scottybm1]

Re: Killed my battery

I pulled the battery and am going to keep it in the garage for the rest of the winter. I have a cutoff switch that was off so there was not a drain on the battery. We've had some very cold snaps here and I figure with the lack of use it just drained it. I figure I'll throw it in the boat this spring, install a maintainer and hope for the best.
Thanks to all.
Scotty

 

[cityboy]

Re: Killed my battery

get a smart charger from wal-mart for about 50 bucks , it is small and easy to keep mounted in ur boat . after i get back i charge over night on my trollin battery . i never have to charge my starting battery but the first time of the season !!!

 

[cribber]

Re: Killed my battery

Aren't Optima red and yellow tops gel cells? Recommended for maximum performance!

Optima batteries are AGM. Gel cells are an older technology that uses a silica based gel to hold it's charge and is the predecessor to AGM technology.

http://www.batterystuff.com/tutorial_battery_gel_agm.html