Questions about Riko Charger

[technics100]

I have just bought a second hand Riko ARM2 charger, it fast charges in 30 mins and slows charges over 12 hours

The charge rates are as follows

Fast 21VA = 21 / 7.2v = 2.91 A = 2916mA

1700 mAh / 2916 * 1.4 (factor) =~ 0.81h = 48.6 minutes

Slow 1.3VA = 1.3 / 7.2v = 0.180 A = 180mA

1700 mAh / 180mA * 1.4 factor =~ 13.2 hours

So really its not a 30 min charger as it takes 48 minutes to fully charge a 1700 mAh pack, is this correct?

Does anyone know if the charger has peak detect and trckle charge?

Cheers

[pauljmuk]

Not sure.

Peak chargers will either switch off or turn to trickle when the battery is fully charged - they sense the charge and cut the power.

Normal fast chargers are set to a timer I believe. If your charger is taking different times for different size batts, then presume it might have peak detection.

[quik_d]

if its the one with a 30 minute dial then no it doesn't have peak charge. If you don't turn the dial it will trickle charge, turn the dial to fast charge. Very common charger and i never had any problems with mine. My 2400 and 2000 battery i do for an hour, 1400's i do for 30minutes usually.

[DJTheo]

Your calculations are correct, but often the written specs aren't very precise or correct, you can turn the dial for another 10-15 minutes, your best check is your hand, when the battery gets around 40C, disconnect it.

Cheers

[GPZ1000RX]

Not many people know this! These clockwork chargers only use a big fat low value resistor and the clockwork timer to work. The timer is there to stop you cooking your nicads if you forget you were charging. They didn't fully charge from FLAT, a 1200mah batt way back in neolithic times in 1/2hr so theres no chance with 1700's etc. Also the charge current is certainly too low for hi cap batts you need a good 5A for 1700s to get the best from them. A good guide is 2.5 X capacity = charge rate (ish)

ie. 2.5 X 1.7 = 4.25 Amps

But don't go beyond about 5.5A for ANY size battery