FIVE AMP VOLTAGE REGULAR TO-220's or TO-5's ?

MEXICOWANDERER wrote:
I'm running into a situation where the hotter than hell temperatures here make fixed voltage charging of -expensive- lithium ion batteries and nickel metal hydride batteries iffy. I would like to back the voltage off 2-3%

Also, those little monsters are not all of like construction. Is there a website that has charts for these cells, and recommendations for temperature compensation?

The issue is power outages, running a 4024 inverter just to charge batteries, and finding a sixty dollar lithium battery (tool) that lasts only a year with perhaps ten hours of use on it. I am referring to new DeWalt stuff so quality is not an issue. It's either back the maintenance voltage down or use a cycle timer. It's be nice to find an easy to program, inexpensive cycle timer.

Some of my NiMH stuff will self-discharge to zero in a month or two. Crappy circuit design allows the float voltage circuit to fail and even though a charge indicator LED glows green, the battery is deader than a stick. The damned thing needs to have it's switch recycled daily. Aghhhh!

With low loads, the Trace is giving me efficiency somewhere in the high seventies - stupid to use 80% of battery wattage energy to maintain an inverter circuit. Hence all these DC to DC questions. Summer outages are due to storms as in overcast skies, so battery recharging has to be done via generator, four dollar a gallon gasoline or diesel and a 62 mile round trip to go get it. I gotta get 600 - 800 watts worth of panels up on the roof, but summer thunderstorms, tropical storms, hurricanes can cut panel output 95% for days on end.

Umm.. you do realize that they DO make 12V CAR chargers for many cordless tools?

Here is one.. Dewalt Car Charger

It would be foolish to attempt to home brew your own charger or mess with the charging voltage of ANY Li-ion battery. In fact those batteries have a built in circuit which can disconnect the battery in case of over charge or over discharge currents.. Those protection circuits are there to protect YOU from a very nasty fire hazard.

And YES, I have personally seen the affects of a Li-ion battery on a device which the charging circuit malfunctioned... Burned a person and melted the device..

I STILL love my old school Makita 9.6V cordless drill, saw, sander and flashlight which used Nicad batteries.. Dead on reliable, you couldn't give me one of these newer higher voltage cordless ones even if you gave me a million dollars too boot.. These newer high voltage cordless items are not designed for a long life of the battery...