Re: Portable batter packs and Solar Charging?

From Wear-Hard Mailing list Archive (WH) Maintained by R. Paul McCarty

On 7/11/06,  <> wrote:
...

> Are you aiming for actually running the wearable off solar cells, or
> just using them instead of a "wall wart" charger?

Instead of the "wall wart" charger
...

> time, the solar cells have provided 400mAH [4], which is sufficient to
> keep the laptop/inverter running for another 10 minutes or so. Of

My idea is that I don't use the laptop all the time, rather the
battery is charging all the time, and occasionally if I need to use an
AC appliance (depending on the rating) I can use it for 10 minutes or
so.

> If your laptop or other hardware is more efficient, or you get a
> bigger battery, then you get more run time, at the expense of charge
> time. 7.2V rechargeables are sold at hobby shops to run remote control
> toys.

Those sound like an interesting idea. Small, lightweight, fairly
easily available. I haven't used one in like 20 years, they were all
NiCad's back then. Are the available as NiMH or lithium ion now?

> That thing looks pretty cool. The line "The Powerpack has a nickel
> metal hydride (NiMH) battery you can recharge using household
> electricity or 12 V DC power from a vehicle DC outlet" makes it sound
> like if you can supply 12V at some reasonable current, you may be able
> to charge it off solar cells. Whether you can wear a sufficient solar
> cell is another question entirely.

Charging the battery off DC actually requires an inverter, it does not
charge directly off DC. So that was my concern: that the solar panel
wouldn't be able to provide enough power to power the inverter and
charge the battery.

> If you don't mind long charge times, then using solar energy becomes a
> lot easier. You can get a big solar array, and charge one set of
> batteries at home while you use another set out in the world. The main
> downfall of modern photovoltaics is the power to size ratio is poor,
> but if you don't have to carry it, that's not a problem. In my
> opinion, this may be the way to go for solar until the energy density
> gets higher.

I was thinking I'd get a little charge out of the backpack that I
would be wearing around anyway, and then be able to use that for a few
minutes once or twice a day to power an AC device.

...
> like that guy did, they are enormously heavy. I get away with using
> 7.2V toy car cells because I built my own power regulation board. They

So you have a single 7.2V battery and then regulate the power to some
other voltage?

Thanks again!

--
Craig

_______________________________________________
Wear-Hard mailing list

http://www.haven.org/mailman/listinfo/wear-hard