Align Lipo 2100mAh 20C

[crash-alot]

Align recommend that the 2100mAh Lipo cells be charged at 0.5C

Does that mean I set the Charge Rate to 1.05Amps?

This is what I've done and with the battery 65% discharged my charger puts back 1130mAh, 12.4v after 66mins and STOP

I know the battery is not fully charge so I then put it back on charge. After 44min another 200mAh is added and the voltage then reads 12.6v

Why is my charger saying the charging is completed after 66mins, is it confused because I reduced the charge rate to 1.05Amps (0.5C)?
The charger is a Pro-Peak Sigma AC/DC and Align balancer

[charlieh]

Align recommend that the 2100mAh Lipo cells be charged at 0.5C
That make me believe it is not a good battery.

Does that mean I set the Charge Rate to 1.05Amps?
Too bad, you have to follow their instruction and charge at 1.05A.

Why is my charger saying the charging is completed after 66mins, is it confused because I reduced the charge rate to 1.05Amps (0.5C)?
That make me believe the internal resistant (IR) of the cell is pretty high (because of the 0.5C charge rate). During charge, the IR will create a virtual voltage, the higher the IR, the higher the virtual voltage. When the charger detected it is 12.6V and stop, it actually comprise of 12.4V actual + 0.2V virtual voltage which disappear when the charger disconnected.

When you go back and charge, the charger switch to CV mode where it will gradually reduce the current to eliminate the virtual current and at the same time the balancer also drain current that make charging taken even longer. That also explain why it take you 44 minutes to charge the last 200mAH.

Another possibility is the battery itself is not balanced, the charger stop when one cell reached 4.2V the other remain at 4.1V that make it 12.4V (a very significant variance), when you go back and charge, the charger give a very low current to the cell, enable the balancer to function and drain the current until all reached 4.2V. (This is unlikely as I don't think the align balance can talk to the pro-peak charger).

[crash-alot]

That make me believe it is not a good battery.

The battery has done only 5 cycles. I don't think the battery is bad imho.


That make me believe the internal resistant (IR) of the cell is pretty high (because of the 0.5C charge rate).
The charger's LCD display reported12.4v after 66mins. I'm not convinced by this theory. [/quote]


Another possibility is the battery itself is not balanced, the charger stop when one cell reached 4.2V the other remain at 4.1V that make it 12.4V (a very significant variance), when you go back and charge, the charger give a very low current to the cell, enable the balancer to function and drain the current until all reached 4.2V. (This is unlikely as I don't think the align balance can talk to the pro-peak charger).
I'm charging the cells through the balancer. The balancer can also work on its own. I checked for balance using only the balancer; no balancing was required


Any more ideas on this. Is it a limitation of the charger? Is it possible that the charger is expecting a 1C charge?

[andeck]

my charger also does this. it is the pro peak Prodigy II. PErhaps it is the manufacturer?

I have charged an align batt, also about 4 different cheapies, and it will always stop at 1210mah at .5C charge rate. at 1c, it will go higher, but stop at a lower V. getting some kong powers in a few weeks, so I can report the difference perhaps if there is any.

[Super_Si]

The Pro-peak prodigy 2 and the Sigma will only allow up to 110% of whatever you program in, as a safety feature. Unfortunatly this means you can't charge lipos slowly without it cutting off like this.

IE. setting a charge rate of 1A, the charger would cut off at 1100mah.

Charging at 1800mA should be fine, however the packs are ok for 1c, and the 20c packs are the better of the packs align make. I've had no problems quick charging mine either at 4.2A, but then that was through a ballancer.

Hope this is helpful.
Regards,
Simon

[andeck]

I see..thanks for that simon.

[crash-alot]

The Pro-peak prodigy 2 and the Sigma will only allow up to 110% of whatever you program in, as a safety feature. Unfortunatly this means you can't charge lipos slowly without it cutting off like this.

IE. setting a charge rate of 1A, the charger would cut off at 1100mah.

So can if I discharge the Lipo to 80% and 1680mAh is to go back in, can I then in theory set the charge rate to 1.530amps to give me max 1683mAh (1.53amps x 110%)? Thereby keeping the charge rate closer to 0.5C as per Align recommendation.