Total Charge 3, On then immediately off

[rockfordpi]

Total Charge 3 on mid 90's Marathon with Anderson connector.

When I plug into Cart it clicks on and jumps to high amps then immediately clicks off. If I leave plugged in, it will do this periodically.

Have tried on a cart with new batteries with high (but not full) charge level as well as a cart with older batteries at 50%. Same result on both.

Diodes Checked good (Continuity one way only).

Checked Capacitor, Ohms builds up to around 300 and then goes to open line (OL).

I do not have to manually reset fuse with red button on front.

I am guessing that leaves only the control board, otherwise, what am I missing?

[JohnnieB]

What does the On-charge voltage climb to when it shuts off? Should be 45V +/-1V.

[rockfordpi]

Originally Posted by JohnnieB

What does the On-charge voltage climb to when it shuts off? Should be 45V +/-1V.

No, not getting nearly that high, I think around 39 volts. However, I have not checked the charge at the exact moment charger shuts down

[JohnnieB]

The control board is a semi-smart switch that has nothing to do with the actual battery charging other than starting and stopping it.

It turns on the charger circuit (Ferroresonant Transformer, Boost Capacitor and Diodes) if the voltage of the battery pack it is connected to is high enough to energize the relay.

It turns off the charging circuit when the voltage of the battery pack it is connected to climbs to about 45V.

It also turns off the charging circuit if the battery pack voltage fails to reach the cut-off voltage withing an allotted time. Typically 12 or 16 hours.

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If the charger shuts off before about 45V is reached the control board is bad or the battery sensing input to the control board is somehow show a a 45V reading when it doesn't exist at the battery pack.

Check the voltage on the Red and Black wires on the control board while charger circuit is turned on. It should read the same as the voltage measured between the main + and - terminals of the battery pack.

If you bypass the relay on the control board, the charging circuit will be on as long as the power cord is plugged in, so you can get your batteries charged.

[rockfordpi]

Originally Posted by JohnnieB

The control board is a semi-smart switch that has nothing to do with the actual battery charging other than starting and stopping it.

It turns on the charger circuit (Ferroresonant Transformer, Boost Capacitor and Diodes) if the voltage of the battery pack it is connected to is high enough to energize the relay.

It turns off the charging circuit when the voltage of the battery pack it is connected to climbs to about 45V.

It also turns off the charging circuit if the battery pack voltage fails to reach the cut-off voltage withing an allotted time. Typically 12 or 16 hours.

------------
If the charger shuts off before about 45V is reached the control board is bad or the battery sensing input to the control board is somehow show a a 45V reading when it doesn't exist at the battery pack.

Check the voltage on the Red and Black wires on the control board while charger circuit is turned on. It should read the same as the voltage measured between the main + and - terminals of the battery pack.

If you bypass the relay on the control board, the charging circuit will be on as long as the power cord is plugged in, so you can get your batteries charged.

Just got back to this project.

With cover off, I can hear the relay on the control board engage and then release within a variable number of seconds later.

However, there is still pack voltage on the red wire after it releases. If I am reading correctly above, this means control board is bad?

[JohnnieB]

That is a pretty good indicator.

Where are you putting the negative test lead when you measure voltage on red wire?

[rockfordpi]

Originally Posted by JohnnieB

That is a pretty good indicator.

Where are you putting the negative test lead when you measure voltage on red wire?

Going to the black lead where it goes back to negative terminal on the charger plug, right there close to the amp meter.

It is so odd, it starts charging and the relay just lets go and shortly after I reconnect it, it engages and lets go again. It is pulling pretty heavy amps when it clicks off. But if that board is only monitoring voltage, it seems like it has to be the board or relay, like you said above.

[JohnnieB]

The control board is a semi-smart switch.
If it senses about 30V or so between the red and black wires, it energizes the relay.
When the on-charge voltage climbs to about 45V, it de-energizes the relay.
If the on-charge voltage fails to reach about 45V within about 16 hours, it de-energizes the relay.
Once the relay has been energized and then de-energized, it won't energize the relay again until the voltage between the red and black wires drops to about 0V (charger disconnected from cart).

If you by-pass the relay contacts, the charger ought to come on and stay on until the charger is unplugged from wall outlet, so you can charge your battery pack while waiting for a replacement board. Letting it charge the batteries for 16 hours or so won't hurt them.

[rockfordpi]

Originally Posted by JohnnieB

The control board is a semi-smart switch.
If it senses about 30V or so between the red and black wires, it energizes the relay.
When the on-charge voltage climbs to about 45V, it de-energizes the relay.
If the on-charge voltage fails to reach about 45V within about 16 hours, it de-energizes the relay.
Once the relay has been energized and then de-energized, it won't energize the relay again until the voltage between the red and black wires drops to about 0V (charger disconnected from cart).

If you by-pass the relay contacts, the charger ought to come on and stay on until the charger is unplugged from wall outlet, so you can charge your battery pack while waiting for a replacement board. Letting it charge the batteries for 16 hours or so won't hurt them.

I need to get some bigger jumper wires, I jumpered around the relay with short small gauge electronic jumpers and it came on but that wire heated up very fast.

Also, this may be a question for another post or PM, but can you give me the cliffs notes on how to replace two diodes in another center tap charger (36 volt ezgo powerwise) with a Bridge rectifier?

I have worked through the logic in the past, figured it out and done it on my variable DC Power Supply, but my memory is not what it once was and so I am starting back from scratch.

[JohnnieB]

Originally Posted by rockfordpi

1. I need to get some bigger jumper wires, I jumpered around the relay with short small gauge electronic jumpers and it came on but that wire heated up very fast.

2. Also, this may be a question for another post or PM, but can you give me the cliffs notes on how to replace two diodes in another center tap charger (36 volt ezgo powerwise) with a Bridge rectifier?

I have worked through the logic in the past, figured it out and done it on my variable DC Power Supply, but my memory is not what it once was and so I am starting back from scratch.

1. I use a 1-F to 2-M spade adapter to bypass the relay. Something like this:
https://www.amazon.com/Supco-T1122-C...ector+splitter
Of course, I got it at a local auto parts store.

2. Going from a full wave with a center-tapped transformer to a bridge could get a little tricky. You'd have to be careful not to double the output voltage or significantly increase the amp flow.

Safest bet is to just use two of the diodes in the bridge. Connect the two wires that were previously connected to the discrete diodes to the AC input terminals on the bridge and connect the + output to the heatsink.

Maybe feeding each half of the transformer to a separate bridge might work.

Probably be best to start a thread on this subject. I'm a bit rusty in this area also.