It’s hard to imagine the connections to the capacitor having great continuity with mating wires. Good luck and report back if it works.

Some of the folks have switched to lithium with good success. Good option now that prices have come down.

Good discussion in the link provided above.

 

I work on monitors occasionally in my arcade collection... I remember the first time discharging a Tube to recap a chassis... I had giant rubber gloves on with rubber insole shoes and I had the chassis of the monitor grounded to the ground of my house... I was convinced I wasn't going to get shocked... Then that fearful moment came when ai had to use my double insulated screw driver with 3 jump wires going to the grounded frame of the monitor and discharge it... So I did... It literally sounded like a tiny tick and there was no giant blue flame or anything... That was it... Man was I relieved when I didn't get shocked... But that first time I was just fearing the worst zap in the world to come from that tube discharge...

 

I received the new capacitor last week. Here are some side-by-side images of the old and new capacitor. They are both 6uF/660VAC parts.

Since they are a little different in size, I added some edge trim so the original bracket could firmly hold the slimmer (but taller) size of the new capacitor.

And here is the new capacitor in place in the charger.

I tried to charge my cart, but the charger did not engage. When I checked the voltage of the battery pack, it seems like it dropped too low for the charger to sense and turn on (the voltage had dropped pretty low as it sat over the last few months...I read ~35V across all 8 batteries). I've put the batteries on chargers using four 12V chargers, with each connected across 2 batteries. I'll try the Lestronic charger again this evening - by then the base voltage on the battery pack should have gotten high enough to allow the Lestronic to engage.

 

35 volts across 8 batteries…

Any chance one one of the batteries are wired in series by mistake?

If the batteries are truly at 4.375 volts each. I’d question if they will recover at full capacity. Most lead batteries when deeply discharged have reduced energy capacity. Yes they may charge but don’t expect mileage to be the same.

 

I measured each battery individually before trying to put a base charge on them. 5 of them measured around 5V, whereas 3 of them measured 2-3V. I am worried about those 3, yes. But this set of batteries may have never gotten a full charge, given the state of my charger.

It will be telling to see how they behave once the charger is confirmed to be working.

 

Just curious... You said you had a background in electronics... I regularly work on old school video games and pinball machines with a buddy who is an electronics engineer... Seems like changing the cap is kind of parts changing for someone who has a background in this stuff... I'm not the smartest guy when it comes to electronics either but I do have access to a capacitor checker (often times they go out in power supplies and monitors oof these vintage type games) and also I think I'd read that these old school chargers do have a power supply has components outside of just the cap and transformer to make it go from 120vac to 48vdc... Could any of those other components maybe be the cause of it not charging? I only ask because I've never had the opportunity to tear apart and diagnose one of the old school chargers like this... The newer ones are non serviceable and just get replaced if they fail...

 

I have a BSEE (my dad was an MSEE). I've done those cap replacement repairs you mentioned on a number of electronics, too. There was a time when a lot of flat-screen monitors and TVs were using under-rated electrolytic capacitors in their power supplies and they would dry out or vent. The fix was as easy as replacing those caps.

For this style of charger, the main components seem to be the "timer electronics", the transformer, and that capacitor. The transformer is stepping the AC voltage to a level where it can be converted to a suitable DC output (via a diode rectifier board) and the capacitor holds the voltage steady for charging. The timer electronics controls the length of charge and shuts off the charge to the batteries when the full charge is reached.

Here is the schematic for the Lestronics2 48V charger that I am working with:

 

That's funny you mentioned that... A buddy of mine worked for Panasonic over here in Kent or Renton somewhere as an engineer who repaired flat screens and he said something similar... That the same board that is meant power something only as large as a 46" Flat Screen is was being used to power the 60" and larger... He always was saying to me "don't buy a television larger than 46"...

 

I put a first charge on the batteries (the repaired charger turned on, ran through its cycle in about 10hrs, and then shut off). I let the cart sit overnight and then tried to take the cart for a drive and it was moving slowly. I was not thrilled with the voltage reading across the battery pack (only 48V) and those 3 batteries were still about a 1/2V lower than the others.

The charger is engaged for another cycle and it has been running for several hours and the battery pack voltage is still climbing (currently ~52.7V). Once it shuts off, I'll try and take the cart for a drive again.

 

Good luck!

 

Some detail on the charging of the batteries from yesterday and overnight:

• I started the charger on the eGator around 9am. The charge turned on after ~3seconds (good, this delay is supposed to happen if all is working well) and started charging at an indicated ~17amps.
• The batteries charged all day at that level, in the evening the current began to slowly drop, but it was still at just under 10amps when I went to bed for the night.
• Here is the change/increase of voltage across the entire pack (8 - 6V cells) throughout the evening:
  • 5pm 55.6 V
  • 5:40pm 56.2 V
  • 6:22pm 56.7 V
  • 6:40pm 56.9 V
  • 7:35pm 57.6 V
  • 8:20pm 58.0V
  • 8:40pm 58.1 V
  • 9:22pm 58.4 V
  • 9:45pm 58.5 V
  • 10:20pm 58.7 V
  • then I went to sleep for the night
• When I came out in the morning, the charger had shut off at some time over the night (good)
• The voltage across the battery pack (charger disconnected) was 51.0V this morning. This corresponds well to the Trojan battery guidelines of 50.93V for a fully charged battery pack.

So, all this seems to correlate well with the proper function of the charger, and hopefully the batteries will respond well. I will put them to some use cycles over the next couple of days.

That the charging current stayed that high for so long, and continued into the night makes sense with one of the descriptions of the proper function of the charger: as long as the voltage across the battery pack is increasing by 0.012V or more per hour, the charger will continue to run.

 

Thanks for posting the details. It might be worth checking the water level after the prolong charging cycle just to be safe.

 

Good point. Yeah, I was intending to do that. I just haven't made it home from work yet, today.

UPDATE: I checked the water levels this evening and they are good 👍