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How many C's can forklift battery take

sunshine_eggo said:
Given the cold temps, the 31V desulfate is pushing is about right for a REGULAR charge. You may need to wait for warmer weather to truly desulfate.
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I was thinking same thing given the lack of current going in too to warm them up to be tickled. Like trying to debark a tree in winter time, better do that in spring summer.
 
I would have thought, if the batteries were insulated and charged continuously for a day+, they would warm up.

TrukinBear had insulated his forklift battery, and while charging in winter the inverter/charger shut down for battery over temperature.
 
Hedges said:
I would have thought, if the batteries were insulated and charged continuously for a day+, they would warm up.

TrukinBear had insulated his forklift battery, and while charging in winter the inverter/charger shut down for battery over temperature.
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Guess I need to get a sheet of EPS and wrap it with blankets on top then hit it some more.
 
Hedges said:
I would have thought, if the batteries were insulated and charged continuously for a day+, they would warm up.

TrukinBear had insulated his forklift battery, and while charging in winter the inverter/charger shut down for battery over temperature.
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I don't think it was -20°F at the time.

Weldman said:
Guess I need to get a sheet of EPS and wrap it with blankets on top then hit it some more.
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Good time to make sure all the cells are actually topped off with distilled water at this point.

Does your AIMS have a temp sensor? Is it installed?
 
sunshine_eggo said:
I don't think it was -20°F at the time.



Good time to make sure all the cells are actually topped off with distilled water at this point.

Does your AIMS have a temp sensor? Is it installed?
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Yes it does and is installed, very easy RJ11 port to plug in. I think at this point insulation in itself and everything I have won't warm the battery to de-sulphate this battery till it warms up.Weather.png
 
Weldman said:
Yes it does and is installed, very easy RJ11 port to plug in. I think at this point insulation in itself and everything I have won't warm the battery to de-sulphate this battery till it warms up.
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You're probably right. I'm disappointed to hear that unit doesn't offer proper temperature compensation. If you can regularly charge to > 1.250 SG, then you should be able to keep things from getting worse and get decent function out of it... though at -31°F, I'd be surprised if the battery can deliver more than 30-40% of its rated capacity (I didn't look up the charts).
 
sunshine_eggo said:
though at -31°F, I'd be surprised if the battery can deliver more than 30-40% of its rated capacity (I didn't look up the charts).
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Is that actually missing amp-hours?
Or just that the chemistry delivers lower than some arbitrary cut-off voltage at reduced SoC?

If one drained 30 to 40% of rated capacity while at -31F, then warmed battery up, would all the missing amp-hours magically reappear?
More importantly, if we just ran battery down to something like 10V or 8V or whatever, would the power be accessible?
(same question for Peukert and high discharge rates.)
 
We tried that in Alaska on the family homestead, no if they are dead bringing them inside they were still dead , but better able to accept recharging
 
Hedges said:
Is that actually missing amp-hours?
Or just that the chemistry delivers lower than some arbitrary cut-off voltage at reduced SoC?

If one drained 30 to 40% of rated capacity while at -31F, then warmed battery up, would all the missing amp-hours magically reappear?
More importantly, if we just ran battery down to something like 10V or 8V or whatever, would the power be accessible?
(same question for Peukert and high discharge rates.)
Click to expand...

This is for my flooded Trojans:

1641075197099.png
Looks like closer to 20-25%. Ouch.

I don't know specifically, but I suspect it's a combination of efficiency losses and voltage drop - thereby hitting low voltage disconnect prematurely. I doubt warming it up to room temperature would "recover" the lost capacity, but I suspect you'd have a good chunk remaining.
 
sunshine_eggo said:
This is for my flooded Trojans:

View attachment 77978
Looks like closer to 20-25%. Ouch.

I don't know specifically, but I suspect it's a combination of efficiency losses and voltage drop - thereby hitting low voltage disconnect prematurely. I doubt warming it up to room temperature would "recover" the lost capacity, but I suspect you'd have a good chunk remaining.
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And they wonder why I went with FLA instead LiFePO4, imagine battery would of went dead long time ago or not even enough capacity to run a dome light for few hours. When I get my pole barn built the battery will be more in protected space. Last year I managed to keep the lights on with a freezer running, 6KW inverter, and diesel heater when it got down to 40 plus below zero and 60 below zero windchill using 8 GC's on 24V at 440AH. Something tells me it's going to be more brutal here cause this weather is almost 2 months early.
 
Weldman said:
and diesel heater when it got down to 40 plus below zero and 60 below zero windchill ... Something tells me it's going to be more brutal here cause this weather is almost 2 months early.
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It's that global warming again!
You have got to stop using fossil fuel!
 
Hedges said:
It's that global warming again!
You have got to stop using fossil fuel!
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Yeah it tends to do that warming thing till another meteor becomes a meteorite, or a volcano blows it load creating a ash cloud sending us back into another nuclear winter.
 
Round two... lets see how far past 100% we can go till it drops off while on de-sulphate mode. This could be awesome or end catastrophically, either way it's going to be fun ?
 
Weldman said:
Round two... lets see how far past 100% we can go till it drops off while on de-sulphate mode. This could be awesome or end catastrophically, either way it's going to be fun ?
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As long as you keep the electrolyte above the plates, your risk is very very low.

Find the datasheet for that battery and target the SG specified. Tedious, but at some point, you have check all 12 cell. :)
 
sunshine_eggo said:
As long as you keep the electrolyte above the plates, your risk is very very low.

Find the datasheet for that battery and target the SG specified. Tedious, but at some point, you have check all 12 cell. :)
Click to expand...
Not yet as I don't think it's at it's given SG due to appliances that run off it one in particular a freezer says voltage is 23.4 when no solar is coming in and drops to 23.1 by morning when running and when not it says 24.2. Not hard data but it's enough to know this freezer cuts out at 22V and to drop that far on 2010AH battery when it's 20 degrees outside, doesn't sound like battery is awake yet or it's too far gone. The SG is supposed to be 1.29 for it.
I think the time it sat up before I bought it then almost two months of it setting up without a charge it's not coming back from the dead.
 
As you can see in that chart I linked earlier, at -30°F, the capacity of your battery is probably around 25% of rated, so 500Ah. While sitting discharged is bad, the cold actually mitigates it somewhat by slowing down the sulfation process. If your battery was in good shape and fully charged no more than 6 months ago, it's probably recoverable provided you keep it as fully charged as possible (daily) and run an equalization as soon as it gets to be more reasonable weather.
 
sunshine_eggo said:
As you can see in that chart I linked earlier, at -30°F, the capacity of your battery is probably around 25% of rated, so 500Ah. While sitting discharged is bad, the cold actually mitigates it somewhat by slowing down the sulfation process. If your battery was in good shape and fully charged no more than 6 months ago, it's probably recoverable provided you keep it as fully charged as possible (daily) and run an equalization as soon as it gets to be more reasonable weather.
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Yeah it wasn't fully charged, it was at 35 something volts when I got it and didn't have a way to get it online to charge then death in the family had me on other side of the country so it sat the whole almost two months at 35V. I will keep trying, I think I need a more powerful charger to wake it up, this isn't working.
 
We only pull 8AH at max here and the temperature today and yesterday is in the mid 20's above zero. So that's another indication it's not up like it should be.
 
Weldman said:
Yeah it wasn't fully charged, it was at 35 something volts when I got it and didn't have a way to get it online to charge then death in the family had me on other side of the country so it sat the whole almost two months at 35V. I will keep trying, I think I need a more powerful charger to wake it up, this isn't working.
Click to expand...

For ongoing operations, perhaps you need more; however, 80A should be enough to achieve equalization voltages in sane temps. The problem is at 77°F, optimal equalization is at 31.2-32.4V. If you're below 77°, you need to go even higher. Many inverters cut out at 32V, so there are other restrictions.

I'd keep running the desulfate program for 4 hours daily as long as you're seeing the SG increase and you keep adding water.
 
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