I also have used A123 this past flying season on older JetCat ECU's (none are for SE engines) and did not have any problems. I wonder if only the newer ECU's are having the problem?

Just to make Gary J. happy, I want him to know that I did change the setting to 8 cell NiCad in the ECU's from the very beginning of using A123's!

Nick

I was there for Gary's flameouts, and for two others I knew about. All were fixed with setting the ECU to 8 cell NiCd.

When you charge ECU batteries, set the charger to no more than 3.6v cutoff per cell. that will get them 95% full but not over charged.

I have charged A123's to over 5 volts per cell in testing. they eventually bled back to 6.8(3.4/cell on a two cell) volts, but it took a bit. Of course they were ruined, but it was controlled testing. I could see issues if you charge them to 3.75 v/cell or something like that where they have residual, but they truly self bleed in a few mins. One thing I would not do is charge them while plugged into any ecu.

Contrarily, I charge my receiver packs to 7.5 volts all the time. they bleed off quickly as soon as you hit the power in 15 sec or so.

just a little FYI.

This may have just been coincidence since according to Mr Matt (JetCat Tubine Clinic), the voltage settings only affect low voltage indications and alarms, not how the ECU mangages the different voltage. (http://www.rcuniverse.com/forum/m_7990510/tm.htm)

Goose,

Excellent suggestion about the cutoff voltage per/cell. Good way to avoid the "fresh charge" spike.

Just wondering why you recommend not charging while plugged into the ECU?

Thanks,

Craig

The Cellpro 4s instructions suggest a cut off at 95% if you want a "faster" charge. The other 5% is just topping off and balancing each cell which we don`t need on the 123`s. This may be a precaution for the guys running non updated ecu`s. I think i will do that from now on with all my 123 packs.
V..

Thank you all for your inputs.

My ECU failed late last week and I checked the off-charge voltage of a pack I removed from my other Hawk 10.4 but that combo has been flown without problem. !

I plugged in the JetCat GSU to check the voltage of the pack in the model where the ECU failed, 0 !
So it seems that if the ECU shorts, that short stays even if the radio is switched off and flattens the battery. The pack will not charge now as it is still connected to the ECU. (wings on, difficult to access). I will remove later today and check that the battery recovers OK.

Regards, David.

Vincent,

Good tip regarding the charging for ECUs that need updating for A123 use.

Ken