Basic Battery charging help for a beginner please

[bigbadad]

Hi Guys

So i've been away from this hobby for a while (Like 15 years) and have been tempted back......but things have moved on considerably, especially in electrics! So i've got 3300mah NiMH batts and a Ripmax Pro-Peak charger but i'm dissapointed with the batteries perfomance so i wonder if i'm charging them right. They are fine to start with but the performance drops off almost immediately and they don't really last long. So what rates should I be charging and discharging them? I'm currently charging them at 5.0A and discharging them at 0.30A and 1.0V but i really have no idea what i'm doing! Any help or pointers in the right direction would be greatly appreciated. Thank you, Adam

[Kopite]

it might be worth checking to see if you have a duff cell in the pack? Unless it's happening for all the packs your using?

[bigred5765]

i dont think you should be discharging them below 5 volts that wont help nimh cells,

[jim76]

charging at 5 amps is fine. discharge at a high ampage if possible, somewhere around 20A. discharge the cells to 0.9v/cell, so 5.4v for the pack. If you go below this is can damage the cells.

were they new packs or second hand? if they are second hand they they will be a bit dead as NIMH drop off quite a bit after 20 cycles or so.

[bigbadad]

Thanks Guy's. The packs are all brand new and it's happening for all the packs i've got (three). Jim the maximum i can discharge is 1.00A is this OK? 5.4V is no problem. Thanks.

[jim76]

you can discharge at that rate, but it will obviously take a while! The only problem with the low rates is the batteries can get "conditioned" to give out their power slowly. If you discharge them at a higher rate it conditions them to give out power in higher bursts - apparently anyway!