CRAP! Killed the New Battery Bank

[capngeo]

So in a classic Homer Simpson DOH! moment, I left the boat last week, and left the damned 12V fans running. Fast forward a week, I come back aboard and the house bank (4 @T-105) was flat arse dead... ZERO volts. I charged them back up and ran through a discharge cycle of ~60AH which they "seemed" to handle fine, staying over 12V. Ran a full charge cycle utill the charger stopped. I shut down every circuit but the bilge pumps, and I'll check voltage over the next few days.

What's the consensus? Should I scrap the 2 month old bank and buy new, or did I dodge the bullet?

[cheoah]

I would not buy new batteries unless I saw a significant decrease in performance. Just keep using 'em, keep them topped up, filled (if applicable), and try not to fully discharge them again. They are designed to be discharged and recharged over and over, so I would not worry about it.

[DeepFrz]

You need more time to really know. Dockhead did a similar thing a few yrs. ago and his bank is still going strong. I don't remember all the details but that was just after replacing his bank too. Can you do an equalization charge?

[Ex-Calif]

Relatively slow discharge rate. One time occurrence, newer batts.

You didn't do them any favors but it isn't the first time in history someone let a battery go flat...

"Party on, Garth..."

[Jim Cate]

As I understand typical golf cart usage, they are frequently run flat and left for dead on the golf course... and they recover just fine. A good equalizing charge would help get them back on their feet, but just charging them to the recommended 14.8 volts will likely be enough.

Cheers,

Jim

[noelex 77]

It will shorten their life slightly, but there is no need to think about scrapping them.

Fan power draw is quite low so hopefully they have not been flat long. An equalisation cycle would be a good idea.

[Wotname]

What all the above said... +1

[ontherocks83]

You should scrap them. And as a favor to you just mail them to my house and I will gladly dispose of them for you.

I think the quality of batteries you bought is definitely on your side. Equalize, monitor, and then determine their fate.

[capngeo]

Originally Posted by ontherocks83

You should scrap them. And as a favor to you just mail them to my house and I will gladly dispose of them for you.

I think the quality of batteries you bought is definitely on your side. Equalize, monitor, and then determine their fate.

Ok, I'll send them off to you, First Class Mail.... Postal fee is $2397.99, please remit ASAP, and I'll get them on the way!

Thanks to the rest!

[MarkJ]

Originally Posted by Jim Cate

As I understand typical golf cart usage, they are frequently run flat and left for dead on the golf course... and they recover just fine. A good equalizing charge would help get them back on their feet, but just charging them to the recommended 14.8 volts will likely be enough.

Cheers,

Jim

Hi Jim and others...

Can this be correct that they discharge the batteries till they are dead? Or do they have a thingo that stops them when they go down below some set voltage?

If there is that sort of thingo, wouldnt that be good to have for boats that are not live aboards?

Mark

[SVNeko]

Yes, that is part of what all the to do over lithium is all about. Low voltage cutoff should be standard stuff with the size and cost of batt banks these days.

Sent from my SCH-I545 using Cruisers Sailing Forum mobile app

[hellosailor]

Homer, this is what the Big Red Switch is for.

Did you not use it? Or were the fans not run through it?

Either way, there are also gizmos like the "Battery Brain" or "Battery Buddy" that can disconnect loads from a car or boat battery when the voltage hits a low set point, making sure that doesn't happen again. (Yeah, one more thing to fail.)

[jeepbluetj]

Originally Posted by MarkJ

Can this be correct that they discharge the batteries till they are dead? Or do they have a thingo that stops them when they go down below some set voltage?

Mark

The typical lead-acid golf carts have no such thingo. They just get slower and slower and slower until they just won't go anymore.

I say this not as a golf cart pro but as a cheap bastard that plays golf when the rates are twilight $$. So I've had my share of dead carts since it's the end of the day.

The thingo is a low-voltage cutoff, necessary for lithiums, probably not needed for lead acid.

I've personally done the same to the boat batts, and my motorhome batts (2 times in the motorhome). GC2's from costco -- They all came back fine and haven't seen any reduction in capacity. Motorhome batts going on 6 or so years old and used regularly - so party on Wayne...

[smj]

Originally Posted by Jim Cate

As I understand typical golf cart usage, they are frequently run flat and left for dead on the golf course... and they recover just fine. A good equalizing charge would help get them back on their feet, but just charging them to the recommended 14.8 volts will likely be enough.

Cheers,

Jim

This is absolutely correct. I don't think you did them any harm at all.

[Reiziger]

Originally Posted by MarkJ

Hi Jim and others...

Can this be correct that they discharge the batteries till they are dead? Or do they have a thingo that stops them when they go down below some set voltage?

If there is that sort of thingo, wouldnt that be good to have for boats that are not live aboards?

Mark

Can. I killed my 3 month old 12 x 2 Volt Cells by letting run my Webasto for 3 weeks. I was not able to rescue them.....