Timer not working?

[ardb]

Timer appears not to be working.
I just got a '91 ezgo Textron. Batteries supposed to be about 1 yr old but had not been kept charged properly. Batteries were at various voltages, some as low as 2.5 volts.
Charger (Total Charge 20L4) would not start. Brought up 2 pairs of batteries on 12 volt auto charger. Charger started but about 2 hrs later timer knob had not moved. 5 batteries were at 5.9 volts and one was at 6 volts.
110 volt cord plug seemed very hot. (Had been plugged into a heavy extension cord which had been used on previous golf cart.)
As I had to leave for several hours, I disconnected charger and will check out heavier extension tomorrow, and continue charging when I can keep a closer eye on things.

[JohnnieB]

I suspect you have a charger similar to the one pictured. (The 20L4 is the UL listing category rather than a model number.)

The timer knob not moving probably means the timer has been bypassed. The timer serves two purposes, first it shows how long the charger has been charging the batteries and second, if the batteries don't reach the cutoff voltage in 12 hours, it shuts the charger off. The charger will charge batteries without the timer being connected.

There is little hope for the batteries that are down to 2.5V, and the charger will be putting out max amps for a very long time, so the AC power cord will most likely get pretty warm.

[ardb]

Thanks for the reply.

That is the charger.

Timer still turns charger on and off.
I did 3, 2 hr 15 min. sessions with the charger on. Then off charger for about hr.
Battery pack had come up to 39.8.volts. 1 hr resting pack read 38.4

Took cart for a 40 minute at full speed on paved roads, slight inclines. On return pack was 35.9 volts. bats 5,9 each.

Put on charger, output at 20 amps.
3 hrs later output at 40.4 volts, 17.5 amps
3:20 pm Charger off, pack read 38.5 volts, about 6.4 each.

Charger still off.
4:50 pm 37.6 5:55 pm 37.

Noticed dial volt meter is hard wired, (not on switch). Will this pull down batteries some?
These batteries were purchased July 2013., but not on charger for maybe 10 months. I know I will be buying batts sooner than I wish.
Cart was free, so that will make the bite not as painful.
Ard

[JohnnieB]

If you got 40 minutes of run time, those abused batteries are recovering pretty well.

The way that charger is supposed to work is to set the timer knob to the "Start" position and let it run until the control board shuts the charger off.
The number the pointer is point to, is how long it took to charge the batteries.

If the control board doesn't shut off the charger within about 12 hours, the timer is supposed to shut it off. Later control boards have the back-up timer built into them and the mechanical timer was eliminated. Some of this type chargers have been retrofitted with control boards with built in safety timers, so the mechanical timer is redundant and was bypassed.

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The batteries that came in my cart weren't taking a full charge and I stretched their life some by charging the living daylights out of them.

I initiated a new charge cycle on them repeatedly for a couple weeks and they perked up to almost normal for their age.

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Here is a Voltage vs SoC chart. The voltages on the chart are measured about 12 hours after the charger shuts off.

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The voltmeter doesn't draw enough current to matter. Leave it connected direct.

[ardb]

Thanks, JohnnieB,
The cart was running quite strong at the end of the 40 minutes. I was just out of time at the moment so could not go further.

I have had experience with several carts with this type of charger over the last 6 yrs. Always plugged charger in and turned knob counter-clockwise past off and to 1 and noted how far it had traveled. This one is not working. I'll open case and see if there is any apparent alterations of wires.
Ran cart for a short time this morning and plugged it in at 8:30 am. Amp meter went to 20.
11:50 am, meter down to 14.5. Charger off and pack reads 40.5 volts.
Timer knob still on 1.
Gravity test is not encouraging. Clear down to 1. Water level was good.
Will just baby them along.
Will report next week. Going to be a busy weekend.
Ard

[yurtle]

Before fixing it use a 12 volt car battery charger.

[ardb]

Thanks for the replies.

Off charger for 24 hrs. Pack at 38.4 volts
each bat at 6.3 volts.

Charger is shutting off after after 3 - 4 hrs. (Happened while I was gone.)

Putting charger on 2 bats at a time and will see what they will do.

Meanwhile, Light wiring is messed up. Key switch controls lights, not motor control. Brakes supposedly new, but need adjusting.

Will look into a 36 to 12 volt converter and digital volt meter. Current volt meter is traditional dial ,red-green- white which is better than nothing.
I have a recently new digital volt meter, which is what I am taking readings with now.

Other additions will be weather cover, flip rear seat, light switches,. etc. No hop ups.

later. Ard

[gornoman]

Originally Posted by ardb

Other additions will be weather cover, flip rear seat, light switches,. etc. No hop ups.
later. Ard

Yeah, sure. LOL!

[ardb]

Gornoman, go easy on me. You have to say those things when your wife may be looking over your shoulder. My computer is broke so I am typing on hers.

[ardb]

These batteries may go for a good long time considering they had not been charged for about a year and were down to 2.5 volts.


charged them 2 by 2 on 12 volt charger.

Took out for a test run totaling 49 minutes, full pedal, relatively flat blacktop, slight inclines.
Start: pack at 38.4 volts bats at 6.4 and one at 6.38 volts

End: pack at 37.3 bats 3 at 6.24 3 at 6.23

Batteries from Battery Source----golf pro