Ready to Use Nimh Batteries

[Lance Norris]

There is a new type of Nimh rechargeable battery that doesnt have the power loss, sitting in storage, that all the older Nimh batteries suffer from. I bought some of these by Rayovac called Hybrid and now have bought some by Sanyo called Eneloop. Everything I have read about this new technology says that they can be charged in any Nimh battery charger. I have a 30 minute Nimh charger. Will this fast charger hurt these batteries?

[Jason Abel]

Personally I wouldn't use the 30 minute charger on any AA. It's just not good for them to be charged at that high of rate. You would get a much longer life if you used an 8 hour charger. Look at it this way. Most Sub-C (power tool batteries) get charged at roughly 3A. This is typically the max charge rate for many of the cells used. If you are charging a 2600mAh AA battery in 30 minutes the output amperage would need to be roughly 6A which is much higher than even a much larger battery is rated to handle safely. A good rule of thumb is that the ideal charge rate is 1C. 1C = the mAh of the battery divided by 1000. 2600mAh @ 1C charge rate = 2.6A. Check the manufacturers website and find the recommended charge rate. Slower is better for battery life. Heat kills.