Solar charging Canon batteries

Does anyone have any comments on using solar power to charge Canon NiMH
batteries? I'm wondering (in the interests of economy of both cash and
mass) whether it's possible to modify the NC-E2 charger so that I can
connect portable solar panels (or any other low-voltage source) to its
existing charging circuit. My NC-E2 uses about 30W mains power while
charging, so I guess it should run from 15-20W low-voltage input, which
is manageable.

 

Rather than hack into your charger (which might not be so easy), why not use
an inverter?

 

I am a little surprised that the charger takes 30W as that is a lot of
power for, presumably, AA cells. Perhaps it is a fast charger. You will
need quite a large solar area to deliver that, a better solution, and
one which saves hacking your charger, would be to purchase a solar
charger designed for AA cells. You could build one if you have the
skills, but then you wouldn't need to ask the question.

 

Charles Schuler wrote

Energy efficiency. The inverter would probably need 50-80W in to get the
30W for the charger, for the 12W or so which actually charges the
battery. That's 3-4x what I'd prefer to carry around (or pay for). A
bigger problem may be that the NC-E2 claims to output 14.5V, which
suggests that the charging circuit needs an input somewhat higher, which
standard portable PV panels would struggle to supply.

I may open and explore the NC-E3 anyway, it's long out of warranty.

 

G8ILZ wrote

The battery is an NP-E3, 12V 1650mAH.

I've built a number of power supplies, but not for NiMH batteries and
their special requirements. I now see that the NC-E2 charger costs about
200ukp in the UK. It looks as though one of these

http://www.thomasdistributing.com/mh-c777plus.htm

would be a better bet. It's smaller than the NC-E2 and already has a low
voltage input, though it will need 24V in to charge the NP-E3. (And I
couldn't build anything like it for the price.) Worth trying, I think!

 

B&H has one for 30-80W bateries here

http://www.bhphotovideo.com/bnh/controller/home?A=details&Q=&is=REG&O=productlist&sku=305746

but they aren't cheap( $400 USD) . I've seen similar things for
charging the Iridium satellite phone batteries when the operator is
"out in the field" away from civilization without even a car battery
(mountain climbing, etc). .

 

There are a couple of another types available as well at
http://www.solarenergyalliance.com/flexible_solar_modules.htm

 

rcyoung wrote

Thanks for the information. I have an ICP flexible panel and it's
impressively robust, though it can't be folded but instead rolls into an
~8cm diameter cylinder. The folding "military" panels are much more
expensive.

BTW DCB's external batteries look interesting.

http://www.digitalcamerabattery.com/