Customer Comments on the Maha PowerEX C9000 and Powerex Batteries

I thought I'd contribute a few comments on gentle charges using the Maha C9000 analyzer. Some of us are photographers and editors, not electrical engineers, and the C9000 manual is a tad skimpy and/or non-specific aside from its brief 0.1C mention.

The smaller manual for the Maha MH-C401FS charger, like the one I bought for my daughter, is aimed at more pedestrian users and it explains why there is a switch for a slow and a fast charge. The fast two-hour charge (1000 mAh) does not hurt good batteries but it just doesn't stuff as much energy into the envelope as a slow eight-hour charge will. And stretching battery capacity, like most exercise, tends to extend life. So users of this fine little charger [C401FS] with four individual Smart Pulse circuits are set up nicely for sound usage.

The MH-C9000 analyzer with its informative LCD display sets you up fine for breaking in batteries, forming and refreshing but there are no specific recommendations for general recharging of AA and AAA cells. The unit seems to "default" to 1000 mAh so many users will tend to use just that. It is fine for a fast charge of both Powerex and Imedion cells.

For the better, life prolonging slow charges, however, Powerex AA users should use 300 mAh, and Imedion AA and all AAA users can use the C9000's lowest user set rate of 200 mAh as their gentler charging rate.

The 5th charge of my B-set of six AA Powerex cells in the C9000 just completed with these results:

B1 - 2650 mAh at 1.45v. in 884 min.
B2 - 2722 mAh at 1.47v. in 907 min.
B3 - 2799 mAh at 1.46v. in 970 min.
B4 - 2773 mAh at 1.47v. in 923 min.
B5 - 2620 mAh at 1.43v. in 873 min.
B6 - 2687 mAh at 1.44v. in 896 min.

A and B sets of matched Powerex 2700 AA cells were broken-in in the C9000 in mid-August 2007 and the two sets are used in my Nikon CP8800 camera. The A-set cells all recharged in the 5th round to beyond their 2700 mAh rating. The Mahas give me longer service between charges than any other makes have. Also, you're lucky if most other makes come within 200 mAh of their stipulated rating. I've never had any exceed their rating like the Mahas tend to eventually.