See this in OT forums and vee-hickles all the time, especially Diesels with big 1000 CCA dual batts wired in parallel. They buy a $5 1/4 amp wall wart charger from Harbor Fright and want to know why it won't charge them up. The idea is to "size" the charging amps to the ampere hour capacity of the battery. About 10% of hour rate (not CCA) or so is considered a "trickle" charge, fast enough to charge in a reasonable amount of time, not so hot as to damage the battery components. Those big chargers on wheels have maybe a 50 amp setting that will get a dead battery ready to go in an hour but that isn't necessarily the way to go. In the case of dual batts wired parallel what we have now is one Big Ass battery. A nice slow "trickle" charge is maybe 15 or 20 amps. Lead acid batteries will always outgas moderately for a time towards the end of what's called the "absorption phase", this is beneficial and equalizes the cells and mixes up the electrolyte. But it needs to be minimized, a 3/4 amp charger would be bubbling away for weeks. It will work, but it's like trying to fill a swimming pool with a soda straw. Some of the better chargers will charge them up all the way, "equalize" routines and the rest of it. I use the old school "dumb" chargers and let them cook overnight, also run the battery down a hefty bit on the headlights and repeat a couple times. This will remove some of the permanent sulfation on older batteries. When they get juiced up good, I put 'em on the tenders.
Took a picture today of my 60 year old battery charger. Used it today on my plow truck. Don't make stuff like this anymore. Craftsman
I would guess that my charger is 50-60 years old. It has a meter like the one in post 33. It does not do 6volts nor have a light on it. I brought it home from vietnam in 1971. It was abandoned with a navy river boat. It worked for a few years and then quit. I had a "noisy" trans from a computer terminal I worked on. My dad got me a BIG diode and wired it up for me and I added a circuit breaker. It will start charging a DEAD battery at 2 amps and raise to 4 amps after a half hour. I usually leave it on for 24 hours and it goes down to 2 amps when it has charged the battery. It reads 16 volts when I first hook it up. It reads somewhat lower when finished. The transformer was part of a recall I did on a great deal of terminals. I think I kept 3 more as spares but never needed them.
I need to replace my corroded battery charger alligator clamps. What is the best metal to withstand the corrosion, copper, stainless? Also, I'd like the clamps that look like this and don't snag on everything. Is there a different name for them?
The Jalopy Journal
