RCU Forums

RCU Forums (http://www.rcuniverse.com/forum/)
-   RC Electric Off-Road Trucks, Buggies, Truggies and more (http://www.rcuniverse.com/forum/rc-electric-off-road-trucks-buggies-truggies-more-147/)
-   -   Voltage of Dead Battery? (http://www.rcuniverse.com/forum/rc-electric-off-road-trucks-buggies-truggies-more-147/4823204-voltage-dead-battery.html)

Rare 10-03-2006 01:28 PM

Voltage of Dead Battery?
 
I have some old battery that havent been used in months. My voltmeter shows to be in the high 7's. Good right? I was just wondering what the voltage would be in a dead battery or a bad battery.

guver 10-03-2006 01:35 PM

RE: Voltage of Dead Battery?
 
An empty (dead) batt should still be 1.2 volts per cell. If allowed to set and is much below 1 volt the cell is bad.

hunter306 10-03-2006 01:36 PM

RE: Voltage of Dead Battery?
 
I got a couple of old NiCd batteries with an old Stampede I bought from a guy.

One battery read 2.9v when I checked it, the other was dead flat at 0.0v
Now these were NiCd's so I booted up the ole' Duratrax ICE and put them on at .5amp and let them cook, then depleted and repeated.

Both of them work good. I've noticed the one that was depleted to zero has slightly less capacity than it would new, but the other one is still packing 1900mah in a 1500mah battery.

raz54 10-03-2006 01:38 PM

RE: Voltage of Dead Battery?
 
The only way to accurately check is under a load. Even dead batteries will show voltage.

hunter306 10-03-2006 01:42 PM

RE: Voltage of Dead Battery?
 
Quote:

ORIGINAL: raz54

The only way to accurately check is under a load. Even dead batteries will show voltage.
True. - Very true.

guver 10-03-2006 03:11 PM

RE: Voltage of Dead Battery?
 

Quote:

ORIGINAL: hunter306

I got a couple of old NiCd batteries with an old Stampede I bought from a guy.

One battery read 2.9v when I checked it, the other was dead flat at 0.0v
Now these were NiCd's so I booted up the ole' Duratrax ICE and put them on at .5amp and let them cook, then depleted and repeated.

Both of them work good. I've noticed the one that was depleted to zero has slightly less capacity than it would new, but the other one is still packing 1900mah in a 1500mah battery.

This may be a dumb question: what kept the voltage from rising to the nominal voltage?

hunter306 10-03-2006 04:06 PM

RE: Voltage of Dead Battery?
 
I honestly don't know. The one battery was completely flatline. It had been stored in a discharged state for about 9 months.

Nitronutt 10-03-2006 08:28 PM

RE: Voltage of Dead Battery?
 
When it was discharged, it may have been left with a load on it - completely killing the battery. Nicd batteries are fairly hearty and as hunter can attest, they can sometimes be brought back to life. Over drain a Lipo and your money is as good as gone.

Rare 10-03-2006 09:16 PM

RE: Voltage of Dead Battery?
 
each cell has 1.2 volts correct? So, when checking voltage you have to divide the total volts by 1.2 and thats how much volts per cell?

Nitronutt 10-04-2006 09:28 PM

RE: Voltage of Dead Battery?
 
Each cell is supposed to be close to 1.2v. Older NiCd cells are a little lower - 1.15 - 1.16. The best NiMh Cells Are 1.21 to 1.22v. These voltages are average voltage over a drain cycle.

When checking voltage, take the voltage and divide by the number of cells. Example 7.2v/6 Cells= 1.2v per cell average.

Rare 10-04-2006 09:56 PM

RE: Voltage of Dead Battery?
 

Quote:

ORIGINAL: Nitronutt

Each cell is supposed to be close to 1.2v. Older NiCd cells are a little lower - 1.15 - 1.16. The best NiMh Cells Are 1.21 to 1.22v. These voltages are average voltage over a drain cycle.

When checking voltage, take the voltage and divide by the number of cells. Example 7.2v/6 Cells= 1.2v per cell average.
Exactly what I was asking;) Thanks man!


All times are GMT -8. The time now is 05:07 PM.