Batteries dead as a doornail ??

[potbuilder]

The new rig has a pair of 8D batteries both were nice and snappy when i loaded the boat on the trailer in Mass but when i picked up the boat yesterday in whittier they were stone dead, my meter showed 4 volts in one and 7 volts in the other. My question is if the throw them on a charger will they come back to life or are they junk?? I checked one tonignt after being on the charger all night and all day today and it showed 13.5 volts maybe a good sign or will that go away quickly after being off the charger.
Thanks for the help.

[avidflyer]

It is a crap shoot. I have had them come back and work great for years. Other times they were gonners. Did a switch or a light get left on?

[potbuilder]

I had the main switch turned off but maybe one of the float switches got hung up and drained both batteries.

[bcriverhunter]

I had the main switch turned off but maybe one of the float switches got hung up and drained both batteries.

hi steve!..those 8d's must be expensive, sure hope you can get them back up to snuff!!....13.5 volts sounds to me like you have it on a smart charger??....does your charger have an equalizing mode on it?....i would follow the chargers directions and "equalize' them as soon as possible so mabey you can salvage them?........15 volts+ to get the chemical back in the solution!!........how long was it between the time of full charger in Mass to when you got home?......

as far as battery drain, does your boat have a "hot" panel as well?....our wooldridge has one additional panel that is wired "hot", that the main battery switch wont shut off...this is for the furnaces, so they cant be shut down in cool down mode!....perhaps you have some other "phantom" load from this 'hot panel'---if you have one?)....good luck larry

[potbuilder]

hi steve!..those 8d's must be expensive, sure hope you can get them back up to snuff!!....13.5 volts sounds to me like you have it on a smart charger??....does your charger have an equalizing mode on it?....i would follow the chargers directions and "equalize' them as soon as possible so mabey you can salvage them?........15 volts+ to get the chemical back in the solution!!........how long was it between the time of full charger in Mass to when you got home?......

as far as battery drain, does your boat have a "hot" panel as well?....our wooldridge has one additional panel that is wired "hot", that the main battery switch wont shut off...this is for the furnaces, so they cant be shut down in cool down mode!....perhaps you have some other "phantom" load from this 'hot panel'---if you have one?)....good luck larry

I charged them one at a time disconnected from each other on just a regular charger, It was aprox 2 1/2 weeks from mass to alaska so i don't know how long they were dead or being drained. Only thing i can think of is that the 2 bilge pump/float switches and 1 bilge high water alarm somehow got stuck and ran the batteries dead. I think i had them shut off but don't remember for sure.
I have another charger that is a smart charger(forgot i even had it??) i'll try using that one and see what happens. It charges up to 15amps and has a digital diagnostics panel so maybe that will tell me if the are shot or not. Thanks for the help.

[JOAT]

If they didn't reach "zero" volts, they should charge up and work just fine.

Good lesson on why you should completely disconnect batteries during out-of-water storage and transportation. A master disconnect switch (or battery selector when you have 2 batteries) is an easy way to go for trailered boats.

[homer]

the bilge pumps may be wired direct to the batteries, so they work with the battery switch off.

[Paul H]

On the upside, you know it'll be worth finding out where the stray current is going. Much better to find out the problem before heading out to a remote location and finding dead batteries.

As far as weather or not they'll come back, hard to say. You might consider changing out one of the them for piece of mind, or carry and extra battery for emergencies.

[JOAT]

Actually, it's pretty easy to say. Once they are charged back up to 13VDC+, disconnect them and let 'em sit for a day or two. Check the voltage. They shouldn't have dropped below 12VDC. If they did, there is internal damage. If they hold the charge, they are good.

Another thing you'll want to do is shut off everything, disconnect one terminal of the batteries and place an ammeter inline between the battery and the main feed to the boat. See how much draw there is with everything off. If it is more than zero, you have something using power that you need to isolate. The easy way to do that is to start pulling fuses or circuit breakers at your power distribution panel. Remove them one at a time to see if it changes the current draw. Put each one back in before moving to the next. You'll usually be able to narrow it down to a singlular item or distribution this way.

[potbuilder]

Hey thanks for all the info guys. Went back yesterday and the one i had charged up here shower 11.75 volts and the meter jumped to 12 a few times, hooked up the batteries this morning and hit the start button, instant start of the John Deere on one battery the other which i charged with my generator running a battery charged didn't have enough juice to turn the engine over so i brought it home for a long good charge. I will take another battery with me on the first trip so if they puke at least i'll have something to start her up with.

[alaskapiranha]

A good thing to do if your charger is not a pulse type and most are not is to sit a switch the switch to start mode or high amp and back to 2 amps. This is what a pulse charger does auto type. It cleans the lead plates.
Told to me by a US Navy Battery Tech
I do mine once a year no matter what.

[dipnet]

Good luck with your batteries! I`m just hoping you enjoyed some lobstah and fried clams whilst you were there.

[skydiver]

If you are coming into Anchorage anytime soon, take both batteries to Batteries Plus (I think) on International Airport Road. They can test them the right way and I don't think it costs anything.

[jrogers]

Steve,

Do you not have a different battery for starting vs. house batteries? Typically 8D batteries are house batteries, which means they are designed for lighter current draw and a deeper cycle. The starter is a pretty high current draw, and I am not sure of the issues starting off of a house battery.

[JR2]

Another vote for pulling them and taking them to batteries plus in Anchorage. Ask for Larry and tell him John Rathert sent you. Larry will load test them, test the acid and give you a straight answer. He just tested my two 6 volts for my camper after I had a similar problem. Make sure you charge both of them good before you take them in as it just makes for a better test.