BatteryStation RCR123 were 3.45

I received my two RCR123, and were both shipped to my door at 3.45 volts. I charged them up and they are both at 3.84. Is this normal? I thought they would top off at 4.2 max?

This is the one with "Rechargeable Li-Ion 3.6V 900mAh CR123A battery with short-circuit and low voltage protect board."

Well, I got 8 more rechargeables coming. Just need to wait for my P1DCE to use them in.

Hello Granni,

The 3.45 volts for shipping is normal. The 3.84 volts is not fully charged. Try charging them again.

Tom

In the LiPo world 3.80-3.85 V is currently normal for storage/shipping. That corresponds to roughly half charged.

I saved a post on LiOn resting voltage vs remaining capacity quite a while back. I've found it to be fairly useful although the useful capacity remaining can vary significantly depending on the discharge rate and the voltage drop of the cell under that load.

"You can get a pretty good idea of the state of charge of Li-Ion cells simply by measuring the resting voltage. Resting voltage is with the cell disconnected from the circuit and left to stabilize for 10 minutes or more.

A very close (conservative) approximation gives...

4.2V – 100%
4.1V – 87%
4.0V – 75%
3.9V – 55%
3.8V – 30%
3.5V – 0%"

Here's data from a tester on the r/c forums on LiPo that agrees pretty well.

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.6?v = 0%

I agree with Tom's advice to try charging them again but personally I'd be VERY cautious with any liOn cell that was received at a fairly low voltage and didn't charge fully on the first attempt.

What charger are you using? Have you used it before? Any chance your meter might be at fault due to its batteries being almost dead, etc? Both your initial and charged readings are roughly .35 V below what I'd expect.

Mike

I used the charger from BatteryStation that coincide with the rcr123 from them.

I let it go back to charge, and the light on the charger is green, meaning its fully charged to the charger, and it wont go past 3.84v.

I just received this package this week. This was the first charge.

Gran Nismo said:

I used the charger from BatteryStation that coincide with the rcr123 from them.

I let it go back to charge, and the light on the charger is green, meaning its fully charged to the charger, and it wont go past 3.84v.

I just received this package this week. This was the first charge.

Click to expand...

Do you have any way to check your meter? Normally I wouldn't suspect it but both your received and charged voltage readings seem low by about the same amount.

Mike

3.8v sounds right for a 3.0v RCR123, maybe mislabeled?

Gran Nismo said:

I used the charger from BatteryStation that coincide with the rcr123 from them.

I let it go back to charge, and the light on the charger is green, meaning its fully charged to the charger, and it wont go past 3.84v.

I just received this package this week. This was the first charge.

Click to expand...

Another idea, try measuring the voltage at the battery contacts of the charger without a cell inserted. The cheap LiOn chargers don't usually do any "checking" and always supply a voltage there. Unload without a charging cell, it should be ~4.1-4.2 V.

Mike

Mike abcd said:

Another idea, try measuring the voltage at the battery contacts of the charger without a cell inserted. The cheap LiOn chargers don't usually do any "checking" and always supply a voltage there. Unload without a charging cell, it should be ~4.1-4.2 V.

Mike

Click to expand...

You are right, I did as you suggested and the charger only shows 3.88. So I need to get batterystation to send me another charger.

Thanks for your help Mike.