Battery chargers...

[cfz2882]

...mostly those meant for 6 or 12v automotive batts,but other types too Once saw an old 6 volt one at a rummage sale that was probably from the '40s that had a half wave tungar tube rectifier-probably quite a voltage drop across that tube. Some pre-1950s chargers used a copper oxide rectifier.Selenium rectifiers were the usual through the '50s and up to about 1989 in certain models. Silicon diodes began about 1961. Oldest charger i have in active use is a big one about 30 amps from 1966 and silicon diode. a 10 amp selenium one from 1979 and a couple recent 6 amp Schumacher ones that use a little switching power supply instead of a 60hz iron transformer-these little ones work very well,but are automatic and will not charge a 12v batt from all the way dead-only charges those up to 6v...

 

[qsd-dan]

I have a charger that is probably from the 60's, if not older. Unlike modern junk from the last 30-35 years that will refuse to charge a battery once voltage drops down to a certain level, this baby will charge anything regardless of how dead it's. Yesterday, my neighbor was complaining his charger refused to charge a battery in a truck he rarely uses. I told him to bring it by, mine will Almost fully charged in 24 hours.

 

[cfz2882]

good old charger-very likely a pair of selenium plates against the back panel, smaller chargers the rectifiers rarely give any trouble but larger versions the springy brass contact disc against the sputtered on lead layer can get bad connection over many years-especially if gets wet-and arc: letting out some nasty smelly red smoke If caught in time-weak output, but no rotten egg stench, can be fixed by carefully cleaning the contact disc and where it contacts the lead film over the selenium layer .

 

[goatfarmer]

I've got one from my dad, it's a Dayton sold by Grainger. Probably early 70' s, outside is rusted, but still works good1

 

[pstehle]

I keep a couple good old ones around, no stupid electronics to check the polarity before the juice starts flowing, if I hook it up backwards, that's my own fault! I think DeWalt and others love the new designs, I had 4 "bad" batteries on the shelf before I learned they need a little boost to get the charger to start if they're stone dead...

 

[william8]

It's best to charge batteries slowly, they last longer. Originally used the famous battery Tender brand, but they never last more than 2-3 years, and they don't honor warranties
Now I use one of these, I bought it at least 15 years ago for my bikes, discontinued now:
https://www.amazon.com/dp/B00HZTDKZG

May be why I always get 9-10 years from a battery. If the car is going to, or has sat for a while, it gets attached. I also attach it for 24 hours whenever I get a new battery.

I have an old 6 amp just in case, but never have a use for it.

 

[wayupnorth]

I've got a Sears Craftsman from the 70's that looks quite similar to that original picture but the timer turns it on and there is no 6 volt setting. Still works fine. I used it a few months back to charge my 4 wheeler battery.