2 series 18650 protection circuit cut off voltage

[PhilLG]

Hi,


I bought two of these http://www.ebay.com/itm/2S-10A-Li-i...576?pt=LH_DefaultDomain_0&hash=item4adf036cf8 as protection circuits for batteries I'm building with 2 x LG ICR18650HE2 3.6V 2500mAh in series. Once I got the cells connected and charged the battery worked briefly but the PCM cuts the power (output voltage drops to 0) as soon as the battery voltage drops below 8.4V. I've checked the individual cells and they seem to have equal voltage within about 0.02V. Both protection circuits seem to be doing the same thing which made me think it's less likely to be a manufacturing defect. Does anyone have any ideas or experience with these boards?


Thanks very much,


Phil

 

[InHisName]

Real nifty circuit, there.
It should operate when BOTH cells are between 3.00 & 4.29 v
Perhaps there is an intermittet connection causing spikey voltage that peaks above 4.29 long enough to trigger it off ?
if good solid connection, recheck what's connected. Batt A + to B+, Batt B - to B-, joint A-B+ to MB

I don't see any 'settings/jumpers/etc.'. Can't think of anything else.

Then if all else ok, recheck output and load to be solid connections.