Lipo charging

[scooterboy]

Hi, I have just got a lrp tx lipo 79991 and when I connect it to my balance charger the voltage goes straight up from 7.6 to 8.4 in a couple of seconds but the cell voltage stays at 3.8 per cell. Any ideas?

[CrashBangWallop]

If you put it on charge it should get to 8.4v. This is the maximum charge voltage, once you disconnect it from the charger the voltage may drop slightly to the nominal voltage which would be 7.4 volts for a 2 cell li-po.

This in reality for you means your receiver pack is fully charged already. Best thing to do is either use the pack in your transmitter or discharge it and recharge it and note the Mah the charger has put in compared to what is on the label - 2400Mah.

[Big paul]

I think the guy has a 3 cell transmitter lipo battery,sorry mate can not help.

[RudolfXC]

I think the guy has a 3 cell transmitter lipo battery,sorry mate can not help.


No, that part number is a 2S LiPo.

You may have a bad connection in the main power wires or balance cable.

[SlowOne]

If you put it on charge it should get to 8.4v. This is the maximum charge voltage, once you disconnect it from the charger the voltage may drop slightly to the nominal voltage which would be 7.4 volts for a 2 cell li-po. That's not how it works at all!!

When the charge reaches 8.4v from the constant current (say 2A for that cell) then the current is cut back until the LiPo is full. When the charge is complete the LiPo should hold 8.4v with no voltage drop until a load is applied.

[BeachBuggyPhil]

Does it ever finish balance charging?

[SLEENAD]

Maybe the 8.4V you are looking at is the voltage your charger is sending to the lipo, combined with the amps, that charges your lipo.

The 3.8V you are seeing then is the actual voltage of just one cell being charged, so if you are charging at the right amps, after an hour or so, that would have to read 4.2V and your lipo is then charged.

[scooterboy]

All sorted, it was a dodgy charge lead :D