A really useful battery charger

Maha Powerex MH-C9000 WizardOne Charger-Analyzer

This AA-AAA battery charger wasn't given to me for Christmas but would have made a good present. My Garmin eTrex Legend HCx GPS and front/rear lights all use AA batteries. For cycle touring, normal batteries make sense as there is no need to carry a charger and replacements can be bought almost anywhere. I use disposable Energizer Ultimate Lithium AA batteries. In my experience they last the longest and because they are lightweight it's easy to carry spares. But they are expensive so the rest of the time I tend to use rechargable AA batteries.

My home weather station, the TV remotes, household torches and various other items similarly run on AA or AAA batteries and dud ones seem to be lying about everywhere. If they are actually dud, because it's hard to tell which are dud and which are not. The Powerex charger I bought recently resolves some of this.

The MH-C9000 is comprehensively reviewed on Amazon. In short:

  • This charger treats (up to four) batteries individually, instead of a group as normal chargers do. Batteries used in series are only as good as the weakest. They may all have, say, 2650 mAh marked on the side but their capacity can vary significantly, and a normal charger will stop charging when the weakest is charged. A set of batteries will also stop delivering current when the weakest is discharged. The C9000 will individually analyse, repair, and match them so they work at their best.
  • Rechargable battery life can be improved by charging slowly and discharging completely. The C9000 has five modes of operation on a per-battery basis with the ability to select from a range of charge and discharge rates and a backlit screen displaying progress, charge/discharge current, each battery's capacity, time elapsed, and voltage.
  • The charger is quite large with plenty of space between the battery slots. Together with the option to select a slow rate of charge, it means battery temperature is kept low during charging so that the unit is safer and can more readily be left unattended – just as well given that some of the cycles take up to two days.

I haven't yet found any newish 2650 mAh Duracell Supreme rechargable batteries with a greater capacity, fully charged, of 2378 mAh. Perhaps they reach maximum performance after a large number of charges and discharges. Sanyo Eneloop AA rechargables have a 'published' maximum capacity of only 2000 mAh but they hold their charge up to 80% over a full year. I bought some once. They're probably still nicely charged in the device I put them in. I just need to remember which...

Anyway, the Maha Powerex MH-C9000 WizardOne Charger-Analyzer seems a good investment and just about qualifies as cycling gear.

2 comments on “A really useful battery charger”

  1. Chris wrote:

    I didn't realise that most chargers would switch off when the weakest battery has reached its capacity. I wonder if it would be worth occasionally charging one at a time – say of a set of four – to make sure each gets a full charge at least now and again. I certainly can't justify buying any more battery chargers. I went through a phase a while ago when I had a load of them.

  2. Kern wrote:

    "How come everything I think I need
    Always comes with batteries?"

    (John Mayer – Something's Missing)

    I dare not show this review to Mary. She's gone through at least one rechargeable battery phase already. All I remember is the shambles of duds and live batteries in various states of discharge all mixed together, some rechargeable, others not. Rechargeables could not be used some devices (cameras. maybe?). It was all very confusing.

    This is one new and improved gadget she doesn't need to know about :).

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