CRAP! Killed the New Battery Bank

[hellosailor]

With a golf cart battery, there's no drain on the battery once someone says "its dead" and walks away. Of course it isn't really dead yet, just too low to spin the motor.

OTOH your typical car or boat battery goes dead when someone leaves a load on. Light or motor, and that stays on until the battery is stone cold dead dead. A typical SLI battery in a car can do about 4-6 of those (depending on duration, etc.) before it is trashed. A deep cycle can handle more, but it still shortens the life.

So, the low voltage cutoffs have a role in cars (where you can usually come back to the car, trip the gizmo, and still have enough power to start) and boats for starting batteries, and can also be used for deep cycle. But for golf carts they'd just serve no purpose, the members would complain "But it could still move..." and they'd probably use the bypass until the cart stopped moving anyhow.

[gonesail]

if they are T105 trojans then i suspect they are still good batteries. charge em up and go sailing!!

[Scott Berg]

You picked the right battery to flat line. As noted, Golf Carts are often killed and left on the course. Keep up the water levels,
use Trojan recommended charging voltages (14.8/13.5) and equalize in a year or so... at worst (because of the slow discharge) you shave a few cycles off the end of life... A good reason not to buy cheap batteries with thinner plates and less electrolyte.


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[onestepcsy37]

My golf course guy says it happens once or twice a month. Sometimes its because it wasn't fully charged the previous night. They just tow it in, charge it overnight with the other carts, and its back on the course the next day.

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[mbianka]

Several years ago I had a small parasitic load on one of the 12 volt batteries in my 48 volt propulsion string. I left it on over the winter and the battery would not charge (battery charger time out) in the spring but, with a little TLC I got it to fully charge: THE BIANKA LOG BLOG: BATTERY INVESTIGATION PART SIX:
It is now behaves the same as the other batteries in the string. Showing no difference under load. I think your batteries should recover as well

[botanybay]

It appears that the amount of time flat is a significant factor. Dropped my 24v bank to 6v (shore power tripped on charger, inverters pulled down to 21v and shut down as desired)

However, 12v thermoelectric fridge powered from wide input DC to DC converter kept going.

Got about 260ah off each string (should be 215ah batteries) so really down.

6 year old bank but pampered to this point with one cell slightly low on specific gravity (0.015 low compared to the rest)

After full charge and an 8 hour equalization cycle and a couple of cycles the low cell is now only 0.010 low.

Definitely not good but not bad. These are Costco 6v batteries (energizer)

[zeehag]

did that to the original batteries in this formosa before i left san diego--- having been associated with this boat since early 2005 helped me with the history of her. they were flattened more than 3 times, and they worked fine for close to 8 yrs. just dont run em outta water.

[delmarrey]

The thing about lead acid batteries is that when they are discharged the acid changes it's consistency. If one removes the draw from the battery they will actually recharge themselves but very slowly and not up to full voltage. The deterioration of the lead brings back the proper consistency of the acid, which brings up the level of the voltage.

With new batteries the lead is in pretty good shape and able to recoop w/o much damage. Now with an old battery the lead is scaled or thin and unable to recover as well, or may even burn the lead down enough to lose its chemical capabilities.

Just make sure the acid is up to level before and after the charge. And the lower the amp during charge the better shape the battery recoop.

[Dockhead]

Originally Posted by 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?

Indeed. I did something like that TWICE, and got away with it. Present set of Trojans doing fine three years later. I wouldn't worry too much about it. Equalize them, and don't do it again!

[Jim Cate]

That's odd: 24 posts and everyone pretty much agrees. This may be a new CF record.

I'm impressed!

Jim

[botanybay]

Originally Posted by Jim Cate

That's odd: 24 posts and everyone pretty much agrees. This may be a new CF record.

I'm impressed!

Jim

Must be a new record!

[sailorboy1]

[QUOTE=capngeo;1598856]. 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.

/QUOTE]

So how are they?

[Ex-Calif]

Originally Posted by Jim Cate

That's odd: 24 posts and everyone pretty much agrees. This may be a new CF record.

I'm impressed!

Jim

Nah...

If we all agree it indicates that we must be wrong and this bank will fail tomorrow to prove us wrong.

Maybe it's karma, or mojo, or murphy. Or just a completely normal, scientific and explainable natural phenomena - like everything else in this world...

[botanybay]

I did end up replacing my 6 year old bank which got flattened after about 8 months.

Interestingly, I thought my propane sensor was on the fritz, replaced it. The new one started acting up after a couple of months.

Turns out it was hydrogen from the batteries! Replaced the batteries and the problem went away.

Ended up with US Battery 2200 XC2 series golf cart batteries. Only have a few cycles on them and still seeing some differences in voltage across the bank during absorption (about 0.1V high across one of the 6V batteries near the end of the charge cycle) otherwise doing well.