Charger troubles
 

I just got an orion rocket pack 5100mah and when i plug it in to my charger the battery buzzes ive got the charger set at 4 amps. if you wind the current down the buzzing gets louder. The charger is a TLP 4000c it says its a pulse charger but ive had a multi meter on it and the voltage stays stable. Im also using deans plugs so the contact is good.

The charger you are using is a 5 year old crappy charger meant for airsoft gun battery packs up to a capacity of 3000mAh...
If it is pulsing your NiMh's you are asking for trouble. The new cells like linear current a lot more.

Buy a new charger. Either a newer one which will do lipos as well or an older competition charger.

Ah, so not the cells then ;)

I used to have a pulse charger but it's a high (ish) frequency pulse which is the buzzing noise. The voltage won't change as the frequnecy is high enough that the voltage won't have time to fall between pulses. What I would say is I'm sure pulse charging is not recomended for Nimh cells.

Thats all i needed to know thanks lads. The charger was a doner from one of my airsoft mates so that says it all.

U have PM :thumbsup: