NiCad Charing - with NiMh charger... - Electronic Circuits Projects Diagrams Free

pittuck · 25th March 2005, 11:18 AM

Hi, i am working on my micromouse and have come across a slight problem. Basically the MINOS micromouse conference is comming up and i might only have one set of batteries and so need a charger.

I have 2 Olympus NiMh chargers and was wondering if i could use these?

One is a 1.2V 240mAx4 charger and the other is 1.2V 490mAx4 charger.

I have 1.2V 1.2Ah batteries, would this charger charge them?

(i know u cant charge nihm in nicad charges, but not sure if the nimh method is ok for nicad).

Many thanks,

- Martyn

fredsm · 25th March 2005, 11:40 AM

Depending on the chip(s) used in the chargers,
the NiCads will be either: undercharged (most
likely) or overcharged (i.e., wrong thermistor
wiring, etc.).
It would be preferable to use a small (3-6v)
supply and a resistor or lamp as a dropping
(current-limiting) resistor, and watch the
terminal voltage. This would get you by
until you could get a proper charger.
NiMH/NiCad chargers are not uncommon.
<als>

pittuck · 25th March 2005, 11:51 AM

well i have a large nicad charger for <=14.4V <=2A and a smart charger for nicads and nimh.

BUT, they are large. I will be traveling on the london undergound at about 8am with a backpack, equipment case and perhaps even a laptop bag. little room for large chargers!

I could get a RC pack charger fron Rapid, but i am planning to move to lipo's for my next bot, so would only use it once!

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25th March 2005, 11:18 AM
pittuck Experienced Member	NiCad Charing - with NiMh charger... Hi, i am working on my micromouse and have come across a slight problem. Basically the MINOS micromouse conference is comming up and i might only have one set of batteries and so need a charger. I have 2 Olympus NiMh chargers and was wondering if i could use these? One is a 1.2V 240mAx4 charger and the other is 1.2V 490mAx4 charger. I have 1.2V 1.2Ah batteries, would this charger charge them? (i know u cant charge nihm in nicad charges, but not sure if the nimh method is ok for nicad). Many thanks, - Martyn

25th March 2005, 11:40 AM
fredsm Experienced Member	Depending on the chip(s) used in the chargers, the NiCads will be either: undercharged (most likely) or overcharged (i.e., wrong thermistor wiring, etc.). It would be preferable to use a small (3-6v) supply and a resistor or lamp as a dropping (current-limiting) resistor, and watch the terminal voltage. This would get you by until you could get a proper charger. NiMH/NiCad chargers are not uncommon. <als>

25th March 2005, 11:51 AM
pittuck Experienced Member	well i have a large nicad charger for <=14.4V <=2A and a smart charger for nicads and nimh. BUT, they are large. I will be traveling on the london undergound at about 8am with a backpack, equipment case and perhaps even a laptop bag. little room for large chargers! I could get a RC pack charger fron Rapid, but i am planning to move to lipo's for my next bot, so would only use it once!