Charging NiMH battery (Duratrax Onyx 245)

[Ge0rge]

I have been charging the NiMH batteries that came with the Summit (7-Cell 8.4V 3000MAH) but the charger never goes in to trickle mode. I typically charge at 3.0A, and am left wondering at what voltage it will slow to trickle charge. I have went to 10.5volts on both packs as I read that a fully charged cell is between 1.45 - 1.5V.

Anyone have said charger or know what the true cutoff should be?

Thanks for the help.

[EeePee]

1.5 x 7 is 10.5 so if it shuts off it's done. Read page 6 in your manual.

[Ge0rge]

Page 6 refers to shutting off and moving to trickle charge. This is figured out using peak detection. However, at 10.52V the charger is still charging at 3.0A. Never had a shutdown as per the manual. I am charging now and am going to see how high it goes before ending and going into trickle mode.

[Trubble]

Originally Posted by Ge0rge

I have been charging the NiMH batteries that came with the Summit, but the charger never goes in to trickle mode............. I have went to 10.5volts on both packs as I read that a fully charged cell is between 1.45 - 1.5V.

Anyone have said charger or know what the true cutoff should be?

It's not going to go trickle at 10.5 on the dot. What voltage it goes into trickle is dependent on cell condition and Delta Peak value. I did a quick 4.3 second scan on the 245 instruction manual, and I didn't see where the Delta Peak is adjustable on that model.
I know it's set pretty high on my 240. The packs get a little warmer than I prefer, and the voltage always goes beyond resting pack voltage.

LiPos, on the other hand, will change from Constant Current over to Constant Voltage at the cell max. of 4.2 volts. But it's not that way with NiMh/NiCads.

Originally Posted by Ge0rge

I am charging now and am going to see how high it goes before ending and going into trickle mode.

Did you ever get to trickle charge?

[snapon boy]

I have that charger and depending upon your battery conditions it times out at 90 minutes. If it times out you may not get the full charge.

[Ge0rge]

10.56v is where it goes into trickle charge. Lipos (2s 7.4v 9400mah 60C) I stop at 8.35v and have my lva's set to 3.5v when trailing.