NiMH battery capacities and rechargers.

I just got a Logitech MX700 cordless mouse. This thing has the wonderful feature of having its own little recharging cradle integrated with the transmitter to set the mouse in overnight, and is supposed to use NiMH cells so you can recharge them all you want (I don’t know why manufacturers haven’t been doing this all along, just like for cordless phones - cordless mice are infamous battery eaters). It didn’t come in retail packaging (I got it cheap), and didn’t include batteries. So, I trotted out and bought it a couple rechargeable AA NiMH batteries, as per the large printed warnings on the thing to use rechargeable NiMH batteries. They work and recharge fine.

But then I noticed the fine print in the booklet says to use batteries between 1500 and 1900 mAH capacity. The ones I grabbed are 2050 mAH capacity. I actually mailed to Logitech, and got a reply that I should contact a logitech rep to order “approved” batteries which strikes me as ridiculous.

Is any harm likely to come here from their little charger charging up the over-capacity batteries?

Probably not. The capacity of your replacements is less than 8% over their stated maximum, which isn’t usually significant. It might take slightly longer to fully charge them, and the charging sensor circuitry might be thrown off slightly (which means the charger will think they’re full slightly before they actually are), so you might not get the full 2050 mAH out of them, but otherwise, you’ll be fine.

Thanks. That might also explain why the battery status display from their software shows about 1 pixel worth of gray rather than completely green, although it says “batteries are good”.