36V Caroche 1980, only charging to 37.5v

[Matagorda]

Hello, I am restoring a 1980 Caroche (DS model indicator on SN) 36V. I have put all brand new Exide GC110's in. I got them put in and just tested the cart for 2 min to make sure all functions (FWD/RVS) worked, and parked it to charge. The batteries showed 27.5v on the bank with my multi-meter. I charged them using an ancient Lester 8714 that is just in horrible shape (came with the car) they charged for at least 12 hrs by now. I am reluctant to leave the charger plugged in overnight due to the heat and smell from the charger. They dont seem to want to go over 37.5V. I had it on to charge for 6 hrs yesterday during the day, and it never budged. The lowest battery voltage was 6.2 and highest was 6.24. According to the charts on here its around only 80% charged. Where do I start to get this thing up to 100%?

[Fairtax4me]

Possibly a bad diode, or a bad capacitor in the charger.
It would probably be good to open it up and clean the cob webs and dirt out of the charger. Take a few pics of the inside and we can kinda figure out what's going on.

Also Lester has excellent customer service and still has parts available for almost all of their chargers, so you can get in touch with them directly and see if they can get you any service information and parts for it.

[Matagorda]

I've only included one picture. I know this thing is old and dirty, But it did charge, but it seems to have topped out at 37.5.

[Fairtax4me]

Right, low output is usually due to a bad capacitor (they fail with age generally).
First is to check that with a multi-meter using the capacitance test function. See if it meets the rating stamped/printed on the capacitor, if you can find/still read it.
If you can't find the rating on it, then you would need to call or email Lester electrical support and find out exactly what size cap is supposed to be in there. The rating of the cap does matter for proper operation on this style charger, it has to be the exact right one.
Another test for the cap is to check the open circuit voltage output of the transformer, but this would also require some info from Lester to know what the output should be exactly.


A bad diode on the rectifier assembly would be the second thing to check. Remove the wires from the diodes and check them using the diode test function.
If either one shows 0v in both directions, or is open then the diode bridge needs to be replaced.

Last would be testing the transformer itself, but as mentioned earlier you would need test specs from Lester to determine if that is good or bad. Very rear for a transformer to fail in one of these old style chargers, so it's not something I would worry about too much.

[Matagorda]

I have checked my run capacitor, it tested bad. I am ordering another. Thanks for your advice. Also, my ammeter on my Lester Charger is not currently operational. Is this required for the unit to operate? and if it is not operating, does that point to another issue? I have found basic Ammeters on Amazon that fit the requirements but aren't branded Lester that should work just fine.

[Fairtax4me]

On that charger the ammeter does have to work, but the needle may just be stuck.
If the ammeter was burned out or electrically open the charger will not output any current at all.
That's an easy check with a multimeter. It's hard to tell from the photo, but looks like one leg of the main fuse on the front of the charger supplies current through the ammeter? So make sure that fuse is good.

[Matagorda]

Thanks, It has worked so I think it may be stuck. I was getting erratic voltage from the crowfoot prongs - but that may be due to the capacitor. I have on photo of the front, and the fuse looks good. I might just change the ammeter just because.

[Matagorda]

Okay, ordered a capacitor, new ammeter, and I am going to replace the AC cord due to come corrosion. I should have everything installed in a couple of days. Will let you know.
Okay if its still sketchy, should I do the diode panel next? The transformer seems to be humming and working so Im hoping by component and component replacement I can get it to work properly. I know these things are beasts, and do well, so I'd hate to trash it. But I figure I'm only gonna be out about 60 bucks if I replace most of the wear components. So Thats not a bad investment if you ask me.

[Fairtax4me]

You can replace the diodes if you want, but if they test fine then I wouldn't bother with it, at least not right away. Try the new Cap and I'm sure that will fix the low voltage issue.
The transformer will hum and make noise. That's just kinda how they are.
If you hear it making a pulsating noise or fluttering noise, then that's usually an indicator of a bad cap, and you'll likely see the ammeter needle bouncing all over the place.
Usually that will pop the main fuse, or trip a breaker.

[Matagorda]

Okay, all items replaced. My Lester 8714 is outputting 43v on the prongs. However after two hours I am still the same voltage 37.3 dang. So where do I go from here?