Hyperion eos0606i NiMH charging help
 

This charger charges my lipos perfect, never have had a problem. I have quiet a few NiMH batteries that I try to cycle every now and then and keep them in use so they don't just go bad. I put them on this charger and the voltage just starts going up and doesn't seem it will stop. I have regular 6 cell packs as well as a few Sub C 6 cell packs and it does it with all of them. If I take it off charge the charger says the packs are at like 7.2V but just seconds earlier on charge mode it was reading 8.5V and higher. I only have it charging at 0.5A. Any help would be appreciated.

Unlike lipo, NiMh has significant internal resistance (IR), so to charge NiMh, the charger has to stay at a higher voltage than the pack to be able to force amps into the battery and overcome this resistance.

It wouldn't surprise me to see over 10+v at the end of a 6cell packs charge. The voltage from the charger won't stop, since the voltage on the pack keep climbing, the charger has to keep raising the voltage to keep current flowing into the battery.

Charging a NiMh requires a diff charger response than what is required in charging a lipo.

That's normal 7.2V NIMH packs can charge and show voltages from 8.5 volts and up to 10V a 7.2V pack that peaks at 10V is not a good pack and is worn and ready to put in the trash.

Thanks for the help. This is the first charger I've had that displayed the voltage numbers, so it just worried me. All is good though I believe. Thanks again