Max current for NiMh AA cells?

I’ve got a two-wheeled robot powered by cordless-screwdriver motors/gearboxes, and they each draw ~3A under load, more when stalled but the torque is so high then I don’t consider that a risk. :mrgreen: Will the AA NiMh cells you stock be capable of supplying the ~6A I need at full power?

Also, are the single cells the same type as in the packs? I ask because I need a 8.4V pack, but not in any of the shapes you offer, so I’m thinking of modding a 6V pack by adding 2 additional cells.

Hi.

The single cell NiMH AA batteries are the same type that are in the packs. I think AA NiMH cells will be able to supply 6 A without too much of a voltage drop.

- Zeeshan

There would be, in my opinion, a significant voltage drop. See the plots on this page for what happens with 2000mAh NiMH cells at 5 amps draw: powerstream.com/AA-tests.htm

Jim is correct. There is a significant voltage drop when discharging NiMH AA batteries at 6A. After testing our freshly charged batteries, I found that they drop from around 1.34V per cell to around 0.63V per cell. Additionally, I tested them at 3A and 1A discharges. When discharging at 3A, they would drop from around 1.34V per cell to about 1V per cell, and when discharging at 1A, I saw a drop from 1.4V per cell to about 1.3V per cell.

- Zeeshan