Charging time

[robk]

I just got a Vanson universal charger along with some 4500mAh C cells. The instructions say that the charger will "time out" in 6 hours (and it did), but at 700mA, the cells cannot be fully charged in 6 hours. Do I start a new cycle after the 6 hour shutoff and wait until the charger detects the -deltaV to obtain a full charge? Also, maybe a stupid question, but when using the supplied 12V 1A wall wart, how do all 4 C cells get 700mA charge current? Anybody have any experience with this charger, like how many hours does it really take to charge 4 C cells?
Thanks,
Rob

 

[Dukester]

I can answer the first question as a month ago I was inquiring about the same charger i.e. the Vanson. I was told after the time out feature shuts down that you restart to finish the charging cycle in order to full fill your 4500 mAH capacity. Other folks will chime in to help you out with the rest of your questions. A lot of the folks on this board who use the Vanson are quite happy with the charger...

Dave

 

[SilverFox]

Hello Rob,

If you take your rated capacity (4500 mAh) and divide it by the charge rate (700 mA) you will find the approximate time to recharge dead cells. In this case a little over 6.4 hours.

If you do not run your cells completely dead each time, the 6 hour timer should not be an issue.

On my high capacity cells, I start the charger, then after a few hours unplug it and plug it back in again. This resets the timer and the charge can continue normally. The other option is to let the last bit of charge come from the trickle charge (70 mA).

As far as getting 700 mA at 1.5 V (times 4) from 1000 mA at 12 V, I believe the voltage difference comes into play. If we look at watts we have 12V X 1A = 12 watts on the supply side and 1.5V X 0.7A X 4 = 4.2 watts on the demand side.

Tom

 

[robk]

Thanks for the replies. I figured that a second cycle would do it, and it did, in about 1 1/2 hours. Since this was the first charge for these cells, it took a long time. I never run any of my other size NiMHs down too bad, so you're right, the six hour timer shouldn't matter for future charges.
Thanks!
Rob