i think my charger or batteries are bad

[mazdawg(Mikey)]

Originally Posted by crash test dummy

please read


http://www.cartsunlimited.net/Batter..._Tutorial.html

http://www.cartsunlimited.net/How_Batteries_Work.html

thanks for the info!

[JohnnieB]

Sounds like you don't want to spend much money on a 36V charger when a higher voltage battery pack is in the future.
It also sounds like you have a fairly decent 36V charger that may just need some diodes or a capacitor to get it going again.

The fact that it hums when you plug it into the wall outlet alone, means the control board has been bypassed, but that won't stop it from charging your battery pack. It only makes it a completely manual charger.

What Make/Model is the charger? Picture of faceplate will suffice.

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You also may have some excessive resistance in the charging loop.

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FWIW: Batteries are a big investment, so don't skimp on the charger.

[mazdawg(Mikey)]

you are exactly right JohnnyB. I don't want to spend a lot on a new 36v charger because I wanna go 48v in the near future. oddly I took the charger to a local shop and he tested the charger. he said it was putting out 39ish volts and my problem was my cord end. I took it back to work and swapped the end out and plugged it back into my cart. when I plugged it back in the gauge needle still didn't move. I left it plugged in for a few hours and nothing. I tilted the charger up to look at it, tapped on the gauge with my finger, and then dropped it back down back on the concrete floor. the needle jumped up and it took a deeper humming tone. Its been on charge again and im waiting to test it in a few hours. if it is indeed charging I don't wanna touch it and it quit again. heres a pic of the charger

[JohnnieB]

That is a good charger and 100% repairable, but a replacement transformer costs more than a DPI charger from Scottyb, however if it hums, the transformer probably isn't bad.

The next most expensive thing is the control board, but you really don't need it to charge your batteries.

What did the ammeter jump up to?

You might just have a bad connection someplace.

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Forgot to add Lestronic II troubleshooting guide

[mazdawg(Mikey)]

the ammeter jumped up to around 15. I just went back there and metered the pack with the charger still charging and It read 42.78. so something good is going on now. something definitely is going on inside of my charger. ill wait till it fully charges and wait till the charger cools off and ill take the cover off and look inside of it.

[JohnnieB]

Since the control board is bypassed, let it go until the On-Charge voltage reaches at least 45V.

[mazdawg(Mikey)]

is 45v fully charged? it hits 45v peak and then settles to 38.2?

[JohnnieB]

Originally Posted by mazdawg(Mikey)

is 45v fully charged? it hits 45v peak and then settles to 38.2?

No, probably not, but maybe, though not necessarily. Most of the legacy ferroresonant transformer type chargers have control boards that shut them off when the on-charge voltage reached someplace in the 44V to 46V range and 45V is in the middle.

Technically, a lead-acid battery is not "FULLY" charged until the specific gravity of the electrolyte ceases to increase while a charging current is passing through its cells. The on-charge voltage tracks the electrolyte's SG, so it can be inferred that the battery is fully charge when the on-charge voltage ceases to rise while a charging current is passing through its cells.

The circuitry need to determine the change in Voltage over the change in Time (dV/dT) did not exist in compact form in the heyday of ferroresonant transformer type chargers, so the makers of the chargers picked a cutoff voltage (whose detection circuitry in compact form, did exist) that would "Adequately" charge most batteries without overcharging the older and weaker ones.

After the charging current is removed from the batteries, the "On-Charge" voltage will typically settle to the "At-Rest" voltage in about 12 Hours.

Conversely, the "Under-Load" voltage will climb to the "At-Rest" voltage in about an hour after the discharging current is stopped.