Unsmoothed car battery charger - is it crap?

would have a fit ;)

high-current apps, AIUI. I think most things had stopped using them by the late '60s, although doubtless there were still some niche applications around after that (and battery chargers may well be one of those).

The smell when they fail is pretty unique (probably what Peter was alluding to!)

cheers

Jules

I have resurected some batteries that have sit around that initially soak very little input current. I have left it go for a week sometimes. I need to try that with some old gel cells I have. After overcharging them, they partially clear up the sulfation. I mostly use deep discharge batteries in the truck. They seem to hold up better after complete discharge, while the truck sits for long periods. The thicker plates seem to last longer. I keep thinking of hooking up that solar cell charger but never have yet.

greg

A suggestion. We always disconnect the vehicle -ve (that connects to chassis/engine block). It avoids the chance of dropping (and potentially welding) a wrench/spanner across the +ve and some 'grounded/earthed' part of the vehicle! Also if trying to measure the voltage output of battery charger do it with at least some load connected, preferably the battery. Best not with a 'digital' meter because the meter may read peak (unsmoothed) voltage which can easily be 1.4 times the RMS voltage. Agree most battery chargers are just a transformer to step down the mains to around 12 to 15 volts and a rectifier/rectifiers in some sort of half wave or full wave configuration. Cheers.

Yes, it certainly could have been upgraded. But then you wouldn't get to see the light from across the garage bay :-)

Besides the newer charger had some nice features that are pretty standard now, like reverse polarity protection and trickle finish.

daestrom

They do hold up better, you can still kill them, but deep cycle batteries tend to have solid plates which are much more resistant to damage from sulfation, they do however have a much lower capacity to begin with due to the lower surface area vs the porous plates.

Actually the capicity is similar, it's the peak current that you compromise on.

It is more a matter of degree rather than a sharp distinction from what i have been able to find of the details.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Eddie saying something like:

still charge up the vast majority of lead-acid car batteries now, sometimes better than the all-singing and dancing chargers.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "daestrom" saying something like:

Would have been a simple job to put in a normal solid state rectifier, just to keep a historically interesting bit of kit working. Otoh, valve rectifiers are still being made in China, afaik.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "JosephKK" saying something like:

That's a perfectly ordinary home-use 4A charger, of which millions were made. As charging state rose, the current fell and it took ages for the battery to start bubbling, usually a day or so. Still best to have it on a timer, I would agree, but 4 hours per session is nonsense.

In message , Grimly Curmudgeon writes

|Septics, eh ?

They are still being made in a lot of places. Likely just not the one he was wanting.

EAT EXCREMENT TROLL

I AM PROTEUS

I suspect it was something like a Tungar argon rectifier or a mercury vapor rectifier and not a conventional thermionic diode as is still made today for tube (valve) audio and such. You need something low impedance for a battery charger.

Probably Mercury Vapor. The thing is likely worth more now dead than it was new.

They're certainly still made for supplying the HT to valve amps etc - but for high current low voltage? Wouldn't have thought there was much demand.

All I can remember is that it looked remarkably like a large, old-fashioned, light-bulb. Had a screw-in 'Edison' bulb base as well. The only difference was a single heavy wire also ran to a terminal at the top of the bulb, opposite the base. The terminal entered the glass and ended in a simple, flat plate above the bulb filament.

Remember thinking it was just like I had read in a book on Edison about how he first discovered the 'Edison effect'. That a heated filament would give off electrons to a positively charged plate.

daestrom

See this link

Solid state is more efficient.