Ni Mh battery charging.

[twiglet]

I have recently purchased a charger with 4 AA Ni Mh "rechargables" from B&Q for my petzl duo. Unfortunately, the info sheet
doesnt mention what the recharging regime for partially used batteries is. Any ideas anyone ? I used to own an FX2 which clearly
stated to recharge for "time and a half".

 

[Burt]

Hi Twiglet

I read somewhere that NiMh's are reasonably robust and can be recharged partially simply by putting them in the charger and charging for the full duration; the charger will work out how much juice they need and charge accordingly.

On a similar note, does anyone know of a RELIABLE battery tester for NiMh's? Some of mine have developed the ability to not hold a charge, maybe through getting wet in the past? Bear in mind I have 54 individual AA's to power up 18 lamps, and they all get mixed up together after trips and in the "Full or Partial/Dead" box! I have tried a multimeter but get confusing results.

 

[Roger W]

That reminds me of the tale I once heard of a student nurse on a geriatric ward who gathered up all the patients' false teeth and dumped them all together in the sink to clean them...   

 

[SamT]

Twiglet - see this http://www.greenbatteries.com/bachfa.html#How%20long%20to%20recharge

Burt - See http://ukcaving.com/board/index.php/topic,8017.msg105730.html#msg105730

You cant really tell how much charge there is left in a battery with a volt meter.

The technoline BC-900 is intelligent and will charge up the cell until peaks then switch to trickle mode.

It also has a test function that will charge up the battery to what it considers full, then discharge it and measure the energy (Then recharge it again) telling you how many mAh are in the cell. (great for identifying fried cells).

And on top of that - it has a refresh mode, that will continually charge and discharge a cell until it cant get any more in. Works well in my experience to bring tired cells back to life.

 

[twiglet]

Thanks lads.....that sounds more like a Tardis than a charger Sam !