BEL LiPo Charger Final V? - RC Groups
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Jul 05, 2003, 10:21 PM
Space Coast USA
hoppy's Avatar

BEL LiPo Charger Final V?

Anybody measure the BEL charger voltage during the final charge period when both lights are flashing? Seems mine might be on the high's reading 8.58V during the red light "on" pulse. As the spec mentions 8.4V as the 'off' V, I was concerned about the 8.58V reading. Any comments?
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Jul 05, 2003, 11:21 PM
Registered User
WJ Birmingham's Avatar
It'll go up to 8.9v @ 1.2a. No worries, it's charging right.

It charges at a constant current, up until it's alternating light colors, then once at the alternation point (8.5v), it stops, checks pack voltage, and if under 8.4v, it hits with pack with .4v higher than the pack voltage, then waits 4 seconds, etc etc.
Jul 06, 2003, 12:54 AM
Purveyor of RC-Opiates
LightFlightRC's Avatar
I have answered the same question before as follows:

I just checked one of mine that is charging now, it is connected to our 15V supply. I have a 3 cell pack on there that is fully charged. It seems the pulsing goes a little higher due to the way the charger works. It tests the voltage and keeps pulsing the power untill the pack reaches 4.23V per cell. Mine is now at solid green, and my 3 cell packs are at 12.7V so 4.23V per cell. I noticed when I hook the fully charged battery up again, the voltage jumps to over 13 volts. It takes a second then the charger stops charging.

It seems the pulsing goes a little higher than the maximum reccomended cell voltage. I think this is needed to get a full charge from this sort of charger. When the pulsing stops the cells are all within spec and it does cut off at the proper voltage. The cell never really takes the charge over the 4.23V per cell, you were just measuring the max voltage of the chargers pulse.

I think you were right to be worried, but this is normal operation for this charger.

We sell this charger at a very good price.

Jul 06, 2003, 01:28 AM
I plant balsa sticks too
luc's Avatar
Yes it's really full charge: 8.54V on mine for a 2 cell pack.
On 3 cells, as I have only a 13.85V source, green light never lits and it charges till 12.63V, which is 99% charge, still ok.

Max charge on li-poly is supposed to be 4.25V per cell, so it's just around 100%.
Jul 06, 2003, 09:29 AM
Space Coast USA
hoppy's Avatar
Thanks guys - It is a very nice little charger. I figured that since so many were in use for so long that it was probably OK but thought I'd check just to make sure it wasn't 'out of spec'. I like the jumpers for changing the cell count and charge rate, one quick glance and you know if it's right.