On Wed, Jan 30, 2013 at 11:22 PM, Wayne Stallwood ALUGlist@digimatic.co.uk wrote:
On 29/01/13 00:13, Anthony Anson wrote:
I have several chargers with different rates of delivery: has anyone any idea where I should start looking for data relating to recharging NiCad and Nion batteries?
Like:
Output of charger Time to charge per mA capacity of each type of battery
Or a way to calculate time, allowing for (expected) losses in the process.
NiCd and NiMH are pretty straightforward...Constant Current charging model. For CC charge models the charge rate is described as a fraction of the cell capacity so 1C is a charge rate in milliamps equal to the cell capacity in mAh
I use NiCd and NiMH quite a lot.
The following seems to comply with the recommended times given by Uniross and others.
Charger rate = 150mA Battery say = 1800 mAH add 40 % for losses
1800 / 150 = 12 hours
allow for loses 1.4 x 12 = 16.8 hrs Compare that with info on the charger and it'll correspond pretty well. I have seen losses quoted for NiMH at 50% - i think that's a bit much.
I think 35% is a better bet to use. My batteries have all lasted a good while - i've got two D's that have been going for 20 years... and they were a cheap make! The AA don't last anything like as well.
james