Total charge 3 possible issue..

[mfinnegan]

Ran the cart a bunch testing out the new motor I got..the pack voltage ran down to 36.2V. Plugged it in the charger and it kicked on to 15AMP and was humming along. Pack voltage climbed to 42V in about 3 mins and then the charger just clicked off...while still plugged in it dropped down to 36.6V in about 10 minutes and won't turn back on.... I unplugged it from the cart and plugged it back in, but it's the same cycle only way, faster shutting off in 10 seconds and dropping to 36.6V in a minute....charger problem?

Edit: quick dumb video https://www.youtube.com/watch?v=vnbVJlOkU5w

[JohnnieB]

Sounds like a bad connection (excessive resistance) in the charging circuit. Someplace between the heatsink the diodes are on and the transformer center-tap inside the charger and the main + and - terminals on the battery pack inside the cart.

Your dash mounted DVM is connected between the battery pack's main + and - terminals, but the charger's control board is looking at the voltage between the heatsink and center-tap. Excessive resistance in the wires/cables connecting those points will cause a higher voltage to be seen at the control board than at the battery pack when there is amp flow in the charging circuit.

Clean all the connections and the problem might go away.

The charger is likely to be working normally, just seeing artificially high voltage.

Attached is a TC-III manual.

[mfinnegan]

Originally Posted by JohnnieB

Clean all the connections and the problem might go away.

The charger is likely to be working normally, just seeing artificially high voltage.

Attached is a TC-III manual.

Thanks for the info and PDF, JohnnieB. I'll crack her open tonight and give a good cleaning.

[JohnnieB]

Originally Posted by mfinnegan

Thanks for the info and PDF, JohnnieB. I'll crack her open tonight and give a good cleaning.

A .22 cal bore brush works well for cleaning the inside of the cart's charge receptacle terminals.

Be a good time to clean all the battery connections.

[mfinnegan]

Originally Posted by JohnnieB

A .22 cal bore brush works well for cleaning the inside of the cart's charge receptacle terminals.

Be a good time to clean all the battery connections.

Definitely will clean battery connections..I have brand new shiny SB50 receptacle plastic end and metal tips...here are some pics. Before I dive in, does this look savable? Or should I get something like this instead? https://www.amazon.com/dp/B07NPWP1FH..._bzlQEbEKQEGNB

[JohnnieB]

Wow, that charger needs some TLC. All the connections look corroded, but only the ones from the transformer to the B- (black) wire in the output cable through the cart's battery pack and back in on the B+ (white) wire through the diodes to the transformer will cause the control board to see higher voltage than it should. I suspect it'll work normally when the excessive resistance is gotten out of the charging loop.

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Don't know anything good or bad about the charge you linked to.

[mfinnegan]

Update: so all I did was take the cover off, remove and clean the heatsink and the 3 connections, mount it all back to the frame and it charged for just under a minute. Then a pop and the brightest light I've ever seen other than a welder or the sun come from this post, and the fuse tried to pop but didn't and smoke just poured from it, AMPS dropped to zero and the cord connecting it to the cart got REALLY HOT and the pack voltage dropped to 28V before I unhooked the **** thing! WOW. I'm telling you it was that simple. Cleaned off the plate and connectors with a wire brush and just bolted it all back together. Safe to say it's toast now

[JohnnieB]

Sounds like Murphy wanted you to get a new charger.

[mfinnegan]

Originally Posted by JohnnieB

Sounds like Murphy wanted you to get a new charger.

Yeah you ain't kidding! Think I'm going with the one I linked earlier. Thank you for your insight on the initial problem.