Requesting schematic for NiMH charger.

SwampGas

Newly Enlightened
Joined
Mar 26, 2005
Messages
3
Location
Denver, CO
First, a general "hello" from this newby...

And my question:
Since I have more time on my hands than I want - I'm
seriously thinking about building my own NiMH charger.
My search on the web has not turned up anything "simple".

I have 2 tight specifications. One, the charger
must be able to deal with single cells. Two, negative
delta V cutoff. Other parameters are flexible - fast
charge, diagnose, conditioning, etc., are not required.

Pointers to previous posts, books, or other web sites
would be appreciated.

Thanks!
Alan
 

evan9162

Flashlight Enthusiast
Joined
Apr 18, 2002
Messages
2,639
Location
Boise, ID
Many here have built a Maxim MAX712/713 NiMH charger. I used rotary switches to select different functions via the PGM pins. I can charge 1-12 cells, choose the time for backup termination, select from 4 current levels, and use a magnetic thermistor if I want to use temperature for charge termination.
 

SwampGas

Newly Enlightened
Joined
Mar 26, 2005
Messages
3
Location
Denver, CO
I looked at the Maxim web site and found a datasheet for
a DS2711. It meets my requirements for single cell
charging and -DeltaV termination. But they aren't available
at Mouser or Digikey.

Any suggestions regarding where I might find a small
handful?

Thanks!
 

chimo

Flashlight Enthusiast
Joined
Sep 16, 2004
Messages
1,905
Location
Ottawa, Canada
Here's a Max712 charger link. It worked well for me. I made a dual charger for charging two single cells independently. I adjusted the schematic and PCB a bit to suit my needs.

Max712 charger link
 
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