dbarrym

My Feedback: (47)

Just curious if anyone else has seen this behavior when using NIMH ECU batteries... I have a P60 that will not start with NiMH 3000 maH ECU packs unless the pack is hot off the charger...at first I thought it was a bad pack, but I have two identical NiMH packs that show the same behavior. It appears these packs cannot supply enough current at startup, as voltage (per the GSU) is dropping into the low 6V/high 5V range when the starter, gas valve, and glow plug all "on".

What is curious is that I am not getting a "power fail" indication on the GSU, but I have seen a number of unusual indications on the GSU before the typical "ignition timeout" error. The other very unusual behaviours I have seen so far:

- Motor spins up, through two start cycles, but never ignites, eventually giving an ignition timeout error;
- Start has spun up and runs at low RPM continuosly, with the start gas solenoid wide open (I can hear the gas hissing), until I turn the Rx power off. The GSU never shows any failure codes or indicators;
- As above but the starter motor spins up to max RPM and will not stop until I pull back both the throttle stick and trim to low;
- Motor spins up, through two start cycles, but never ignites, eventually giving a "glow plug" failure error on the GSU.

I've never seen this with any of my three P120's...the P60 ECU firmware is at 5.0W. I know the NiMH pack(s) are the problem as I can start easily with a "hot" pack, and also when using the stock NiCad pack and a 4000 maH Duralite, with none of these problems.

My question is - why isn't the GSU giving a "power fail" even though it shows the pack voltage dropping below 6 V on start?

Thanks -

Barry

causeitflies

I would try cycling the packs and putting a C10 charge on them. Before fast charging, NiMH packs need a "forming" charge to hold capacity. I use a 3000 NiMH pack on my P60 that works well.

dbarrym

My Feedback: (47)

Thanks...The packs have been cycled and charged at a C5 to C10 rate overnight....but unlless I warm them up with a partial discharge then a fresh charge at a C1 rate, they won't work.

My question is - why isn't the GSU giving a "power fail" even though it shows the pack voltage dropping below 6 V on start?

Barry

causeitflies

Maybe because "power Fail" is a stop/off condition but may not be a mis-start condition? And the pack probably reads good until the starter motor pulls it down. Wait for Matt.

mr_matt

My Feedback: (10)

Hi Barry,

Are you getting any RPM reading (on the GSU) when it is spinning?

Regards,