# Over charging



## F16bmathis (Jun 6, 2008)

I didn't die, get burned or have acid splashed in my face. 144V 225 amp hour lead acid Trojans with a Zilla 1K, Warp 9" motor. All winter, the batteries were cold, and the charge was less than full. So I turned my Manzanita up some. Two days ago, I plugged it in, went to sleep and woke to smoking batteries! Normally 10 KWHz a charge that day was 70! Steam was coming from all the vents, most water was gone. I let them cool, re-watered, and reset the Manzanita for the voltage the pack was at now.

Should I be adjusting voltage of the charger? I occasionally check the batteries, but they seem about at the right voltage 6.45 +/-

Why did it keep charging, other than the charger didn't think it was fully charged yet? Should I vent the chargers heat vent out of the cab of the truck in summer?

Are my batteries shot? I did make it the 16 miles to work on the highway doing 55-65, mostly 65.


----------



## F16bmathis (Jun 6, 2008)

I'm barely making it 13 miles in a truck that normally gets close to 40 miles at 65mph. I'm turning the charger back up and checking voltage, and the battery state of charge. 

Also, the normal 10 KWHz was 12 KWHz last night, more charge, but not enough to make it to work.... I destroyed my batteries didn't I?


----------



## TX_Dj (Jul 25, 2008)

KWHz? I've never see kiloWatts and Hertz applied together. I'm sure it's just an honest mistake on your part.

Yes, it sounds like you destroyed the batteries. You need to check specific gravity in each cell from each battery. You may still be able to revitalize them by adding enough electrolyte to each to restore their proper specific gravity, but most likely the plates inside are damaged from running dry.


----------



## TX_Dj (Jul 25, 2008)

Also, you should not be adjusting the charge voltage of your charger unless it is reaching a voltage that is improper for your batteries *adjusted for ambient temperature*. It is normal for the fully charged voltage to be different at different temperatures, and trying to force the batteries to take a higher voltage charge at say, 45F than what they're rated at that temp (I.e. trying to charge them to the same voltage they would sustain at 78F) is a no-no.


----------



## TheSGC (Nov 15, 2007)

It does sound like they got boiled to death. You should check the SG of each battery, recheck the water levels and take it easy on them for 3 or 4 days, avoid highways and keep the AMPs less than 150 and see if they have any life left.

If your charger didn't shutdown then your voltage was way too high. I don't have a smart charger, but and old skool BC-20 that I unplug before I go to bed.


----------



## F16bmathis (Jun 6, 2008)

Yeah does look funny! Guess I meant KWH's! I've been checking specific gravity in a few cells, they seem close to each other, but I think when I turned the charger down to where the batteries were resting at the next day, it was NOT fully charged. The specific gravity shows an almost discharged state after a "full" charge which only took an hour and a half to charge after driving 14.5 miles on the highway. I've been increasing the charge level and checking the specific gravity every hour at work, hoping to make it further and faster than yesterday without overcharging.


----------



## F16bmathis (Jun 6, 2008)

We need a bumper sticker of your quote "A FUEL AND HIS MONEY ARE SOON PARTED".


----------



## F16bmathis (Jun 6, 2008)

I should have figured it out when it took all day to charge, and the batteries were starting to get really hot. I'm sure I had the charger set for more of a winter charge and never went back down for summer. I remember tweaking it up this last winter, but never thought to tweak it back down when it started heating up. Should have used the specific gravity meter more often.


----------



## F16bmathis (Jun 6, 2008)

I kinda like the KWHz. Think I'll start using that more often. Maybe someone will think I'm on to something!


----------



## rmay635703 (Oct 23, 2008)

A wise investment is a 12hr spring wound timer, unless you are charging really big batteries with a really small charger it shouldn't take over 12 hours to charge.

They sell them for controling hot tubs and other crapola, you wire them into an outlet box.

Generally you should know based on how many ahr you figure you took how long it should need to charge, add a little cushion and set the timer. 

I use one on my automatic charger as well as my antiques because you never know what can happen, I had one battery die and the automatic kept charging because the voltage was low, I ended up catching it on my own while the batteries bubbled, but never again. 

Cheers
Ryan


----------



## EVfun (Mar 14, 2010)

F16bmathis said:


> I should have figured it out when it took all day to charge, and the batteries were starting to get really hot.
> [snip]


You just described thermal runaway. As a lead acid battery gets hotter the charge voltage goes down. This can lead to a situation where excess charging creates the heat that means the voltage applied should go down but since it doesn't the current goes up. This is excess charge so almost all the current goes into heat, which further heats the battery, further lowering the voltage and increasing the current...

Nothing good comes from this and it can destroy a battery the first time if it goes on long enough. I think you pack just died though a few of the batteries may have survived. I've actually started thermal runaway at as little as 2 amps in a tired old Optima. I think the advice to add a upper limit timer that will shut off the charger is a great idea. Once the thermal runaway starts very few charger shutoff algorithms detect the need to shut down. (systems that shut down the charger when the voltage stops rising and amp hour counting based charging will shut down thermal runaway)


----------



## F16bmathis (Jun 6, 2008)

I had contiplated doing that, but figured it would just shut off when it was full. Even the night this happened, I got up at 2AM to close the hood, as it was going to rain soon, saw it was still charging, could've saved me a headache.

I took it to work again, 65 down the highway, made it there, but it got slow, and charged in less than 2 hours, so I checked the specific gravity and found it to need more of a charge. I guess it was really dead when I rest the charger after boiling them. I had checked it every hour during work, and kept creeping it up. Drove home at full speed all the way. Its charging now, but I know I've got to adjust it up a little more.

I'm sure I've shortened thier life, but they seem to be coming back to full power.


----------



## F16bmathis (Jun 6, 2008)

Allrighty then, sounds like a timer is a good safety net. Too bad these didn't die, I could've justified LiFePo4's!

Thanks all.


----------



## mszhao (Oct 17, 2009)

F16bmathis said:


> I didn't die, get burned or have acid splashed in my face. 144V 225 amp hour lead acid Trojans with a Zilla 1K, Warp 9" motor. All winter, the batteries were cold, and the charge was less than full. So I turned my Manzanita up some. Two days ago, I plugged it in, went to sleep and woke to smoking batteries! Normally 10 KWHz a charge that day was 70! Steam was coming from all the vents, most water was gone. I let them cool, re-watered, and reset the Manzanita for the voltage the pack was at now.
> 
> Should I be adjusting voltage of the charger? I occasionally check the batteries, but they seem about at the right voltage 6.45 +/-
> 
> ...


you'd better check your batteries and charger both before using them again.if the voltage of the batteries are normal now?is there any batteries defective so that it leads to overcharing? or if the batteries were over discharged when you were driving?


----------



## F16bmathis (Jun 6, 2008)

Its day three, and I'm back to driving at full speed 14 miles to work, charging, then 14 miles home. No lagging in acceleration. I'm using the Specific Gravity thingy after the batteries are fully charged to see if they really are, and so far they are not, so I'm still slowly increasing the charger back up.

I have not found a single battery that is out of specs with any others yet, but I haven't checked them all. I first checked the ones with the lowest voltage. I gotta check my overall range sometime, see if I'm still getting the 40-60 miles.


----------

