Alltrax controller going into Low Battery mode for few seconds

[mattadata]

Cart works well most of the time, but right after I first turn it on it goes in LOBAT or Low Voltage mode. It only last for a few seconds. It seems like it retards the speed, but then goes away and cart works normal. It will be fine for the rest of the trip...unless I sit stopped for a few minutes. But It always happens right after I turn the cart on.

I watched the log in the toolkit and you can see the LOBAT flag gets set at 11/19/2021 2:47:15 PM (row 254), then returns to normal.

I have a voltage meter hooked up to the battery and I never see it get down to 38.7.....its stays up in the 49v +.

My battery was a little low when I pulled this log, but same thing happens when battery is fully charged. I have 95ah lithium pack. Fully charged is 54.6V.

Any ideas? My thought is that it something might be wrong with solenoid right when it closes, but then remedies it self in a few seconds. Not sure how to test though.

Spreadsheet with data in google docs https://docs.google.com/spreadsheets...it?usp=sharing

[Volt_Ampere]

It almost sounds like the precharge resistor in the Alltrax isn't up to snuff. That could drop the voltage as capacitors charge when you turn on the cart. You are not supposed to need an external precharge resistor with the Alltrax. I don't have on on either of my carts - also running Lithium. I would contact Alltrax and ask them about your problem. Include the log and they will look at it. You could try and external precharge resistor and see if that cures the problem. It goes across the big terminals I believe.

[JohnnieB]

Originally Posted by mattadata

Cart works well most of the time, but right after I first turn it on it goes in LOBAT or Low Voltage mode. It only last for a few seconds. It seems like it retards the speed, but then goes away and cart works normal. It will be fine for the rest of the trip...unless I sit stopped for a few minutes. But It always happens right after I turn the cart on.

I watched the log in the toolkit and you can see the LOBAT flag gets set at 11/19/2021 2:47:15 PM (row 254), then returns to normal.

I have a voltage meter hooked up to the battery and I never see it get down to 38.7.....its stays up in the 49v +.

My battery was a little low when I pulled this log, but same thing happens when battery is fully charged. I have 95ah lithium pack. Fully charged is 54.6V.

Any ideas? My thought is that it something might be wrong with solenoid right when it closes, but then remedies it self in a few seconds. Not sure how to test though.

Spreadsheet with data in google docs https://docs.google.com/spreadsheets...it?usp=sharing

The lobat error shown on the spreadsheet happened during operation when the solenoid contacts are closed, so the issue isn't pre-charge resistor related even if the XCT used one.

The XCT measures the voltage between its B- and B+ terminals and calls it battery voltage even though there are numerous cables, connections and contacts between the controller terminals and the battery terminals.

Since the voltmeter connected between the battery pack's B- and B+ terminals stayed at 49V or so while the voltage between the controller's B- and B+ terminals decreased to 38.7V, there is very likely some undesired resistance between the battery pack and controller.

Also, the battery voltage as seen by the controller decreases directly with the amount of battery amp flow while the voltage at the battery doesn't, pointing to a bad cable, connection or contact between battery pack and controller.

If the cables and their connections are good, it might be bad solenoid contacts.

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Check Pin-9 for good connection and full pack voltage. That is where the "pre-charge" voltage gets into the TXT48 version of the XCT.

[mattadata]

Thanks JohnnieB

Yes, all cables are clean and tight. I measured voltage on pin 9 and it is full pack voltage. I repeated the test at full charge....no lobat alarm, but the cart still goes slow for first 5 seconds or trip.

Volt_Ampere - I contacted Alltrax as well, and they are pointing to the solenoid also.

[Volt_Ampere]

I would try replacing the solenoid then.

[JohnnieB]

Get a solenoid with magnetic blowouts like the SW180 or SW200.