Alltrax Converted DIY Lithium '84 Club Car DS Issues

[jworren]

Hi All,

I have searched for my 'symptoms' for weeks but always end up on posts that end with Alltrax replacing the controller. I have a hard time believing I have a bad controller and want to troubleshoot as much as possible.

Here are the details of the cart:

1984 Club Car DS
Carts Unlimited AllTrax SR48400 Conversion (Worked fine with old 36v FLA's)
NOW Swapped to 48v Lithium packs (Currently running 1) from Battery Hookup
Original Motor
All New Wiring, 10ga for Charging, 2ga for main lines

Issue(s) I am Having:

I can run the cart around the yard, towing trailer, etc. fine and have no issues if I go slowly. Whenever I try to get it on the road, I have a shutdown or a severe reduction in throttle response after getting over a few MPH. In the log attached when you see several rows of 24-30% throttle, I am actually going to full throttle and holding it there (See rows 27-47 & 173-204 in 042223_02.csv). I am also getting intermittent GLOBAL SHUTDOWN, overcurrent, HPD faults (See 042223_01.csv). Sometimes after going down a slight downhill, everything will shut off and I have to turn the key off for several minutes before I can get the cart to move again. The solenoid ALWAYS clicks, even when the cart will not move. The Alltrax always flashed the throttle code, then goes solid green when I watch it with the pedal depressed during a no-movement event.

I have checked all wiring for loose wires, corroded connections, half-blown fuses, etc. and found no indication of anything wrong. I have attached 2 logs and an export of my settings.

Hope ya'll can help!


Thanks,
JO

[Pat911]

Has it ever worked well after the lithium conversion?

Which specific battery are you using?
Does it have an integrated BMS?
If not, have you added one?

[jworren]

My original post has pretty much been my experience since I got the lithium packs. They are rated for way, way more discharge amps than the alltrax can handle and have healthy voltage sitting and under load, so I want to think they aren't the issue even though they are the only thing that changed.

I am using 48v version of these battery packs:

https://batteryhookup.com/products/2...enclosure-fans


I do not currently have a BMS hooked up on the pack I was using to test in the cart, but have started installing a 30a BMS w/ balancing for charge only on the other pack. I plan to install the same BMS on both packs as the cart will be charging far more than it is being driven so my hope is that it will stay balanced.

[Pat911]

You need to get a BMS on that pack to protect for charging and discharging asap. Lithium, especially NMC which is what that pack is, doesn’t like to be over discharged.

Have you checked voltage sag under load on that pack. Remember, it is a repurposed pack and will have considerably less capacity than its original capacity.

[CP241]

Do you still have your FLA batteries? I’d swap them back in and see how it behaves

Running lithium, especially NMC without a BMS is a horrible idea. Especially with repurposed cells. You have no way of knowing what the individual cell voltages are and if they’re balanced. All it takes is one low cell to discharge too low and the whole thing can run away and go up in flames. Literally. Don’t do it.

That said, I’m very suspicious of those battery packs. There’s a LOT of “in theory you should be able to…” on that website. Not something that would give me the warm and fuzzies when buying a battery pack. It also says 300A continuous and then a few lines down says 200A continuous. There’s a lot of contradictions on that page you linked.

Also with 3.7v being nominal voltage, you should be seeing 51.8v or better at rest. I don’t see anywhere near that in your logs. Generally NMC is fully discharged between 2.8 and 3.0 volts per cell. Which would put you around 42v for a 14s pack… not far from the voltages I’m seeing in your logs. Which would indicate your pack is also not fully charged, out of balance, or both.

I may be slightly off in some of my calculations and observations, it’s early and I haven’t had my coffee yet. But I think those batteries are less than desirable to begin with, and not balanced or protected and that seems to indicate your problem to me at a glance

[augiedoggy]

So the battery hookup folks often recommend less that the original manufacturers max continuous discharge on thier used cells just as a measure of cushion because they are used. thats why the original description is 300a and they recommend 200a.

They actually are a very reputable place to buy used cells and if there was a real issue they would take care of it. (I looked at those same cells as well as the larger 36v packs they had before converting to48v myself.

I agree something is not right with the voltage and would expect the alltrax to perform low voltage cutouts at such low voltages.

This is simply one of the reasons you should have a smart bms connected to see whats going on as far as state of charge and performance of each cell. I see the op plans to use a 30a bms.... I assume thats with a relay controlled by the bms?

[scottyb]

What is the low voltage cut off set to ? 28v 38v ?
If you suspect the control is hitting low voltage cut off as Auggie suggests. Simply set the Alltrax cut off at 18v and make a test run.
What is the lowest voltage you see when the problem occurs in the data log?

[jworren]

@CP241 The packs I purchased are 13s, so 48.1v is the nominal voltage. I intend to use the 30a BMS's to trigger a relay/contactor to turn on/off discharge, and have the charging go directly through the BMS for balancing.

I have done a cursory check of individual cell voltages and saw no glaring issues but, again, I will be running a BMS.

Right now I was just doing a quick test before I got all that hooked up, mostly because I needed to move the golf cart out of the garage- I have only driven it a few hundred feet probably in its current configuration. To my understanding, a BMS would only PREVENT the packs from sending voltage (which I know is their purpose), but the LACK of BMS should not be causing the golf cart to shutdown or the controller to see the wrong throttle input %.

@audiedoggy Can you recommend a smart BMS w/relay in case I decide not to rig my own relay to these 30a BMS? Battery Hookup runs their forklifts on these 48v packs and I would have to assume a several thousand pound lift has higher amperage demands than a stripped down aluminum golf cart. I am actually the one who was asking you questions about your headway build, but ended up going with these 48v packs based on the guy I spoke to on the phone at Battery Hookup.

@scottyb The lowest voltage I see in the logs is ~44.6v, off of a nominal of 48.1v for the pack. My settings are attached but it looks like they are gobbledygook for some reason. I have the undervoltage set to something around 32v just to try and eliminate that from the equation for these brief tests. Do you have any idea why the controller is sometimes seeing the wrong throttle input %?

[augiedoggy]

Originally Posted by jworren

@CP241 The packs I purchased are 13s, so 48.1v is the nominal voltage. I intend to use the 30a BMS's to trigger a relay/contactor to turn on/off discharge, and have the charging go directly through the BMS for balancing.

I have done a cursory check of individual cell voltages and saw no glaring issues but, again, I will be running a BMS.

Right now I was just doing a quick test before I got all that hooked up, mostly because I needed to move the golf cart out of the garage- I have only driven it a few hundred feet probably in its current configuration. To my understanding, a BMS would only PREVENT the packs from sending voltage (which I know is their purpose), but the LACK of BMS should not be causing the golf cart to shutdown or the controller to see the wrong throttle input %.

@audiedoggy Can you recommend a smart BMS w/relay in case I decide not to rig my own relay to these 30a BMS? Battery Hookup runs their forklifts on these 48v packs and I would have to assume a several thousand pound lift has higher amperage demands than a stripped down aluminum golf cart. I am actually the one who was asking you questions about your headway build, but ended up going with these 48v packs based on the guy I spoke to on the phone at Battery Hookup.

@scottyb The lowest voltage I see in the logs is ~44.6v, off of a nominal of 48.1v for the pack. My settings are attached but it looks like they are gobbledygook for some reason. I have the undervoltage set to something around 32v just to try and eliminate that from the equation for these brief tests. Do you have any idea why the controller is sometimes seeing the wrong throttle input %?

Ok the packs you linked state the normal 7s but this helps make sense of things..

I would guess you may have an unrelated throttle sensor, sensor wiring or even alltrax failure. You can use the usb throttle feature in the alltrax app to help troubleshoot.
I have a used sr72500 I bought that actually has a throttle input issue where more than half the time when you went to use it, the throttle would only work every other time you depress the pedal like clockwork.. the other 50% of the pedal presses would cause the controller to go into an "over current" error and the alltrax would basically blank out and lose the alltrax toolkit usb connection... I removed it and replace it with something else due to this.

this is the bms I use ironically... I like it. I have the touchscreen addon thats designed to work with it as well. I bought both on aliexpress myself from the jbd outlet store. https://batteryhookup.com/products/7...ithium-ion-bms

[jworren]

Originally Posted by augiedoggy

Ok the packs you linked state the normal 7s but this helps make sense of things..

I would guess you may have an unrelated throttle sensor, sensor wiring or even alltrax failure. You can use the usb throttle feature in the alltrax app to help troubleshoot.
I have a used sr72500 I bought that actually has a throttle input issue where more than half the time when you went to use it, the throttle would only work every other time you depress the pedal like clockwork.. the other 50% of the pedal presses would cause the controller to go into an "over current" error and the alltrax would basically blank out and lose the alltrax toolkit usb connection... I removed it and replace it with something else due to this.

this is the bms I use ironically... I like it. I have the touchscreen addon thats designed to work with it as well. I bought both on aliexpress myself from the jbd outlet store. https://batteryhookup.com/products/7...ithium-ion-bms

That is almost exactly what I am experiencing with my Alltrax! I am going to work with ScottyB and Alltrax to see if they can help me confirm if the controller is the issue and hopefully get a warranty replacement if that is the case.

I think I am going to pull the trigger on those BMS's- I was trying to go cheap on mine but having never done this before I really don't like that fact that I can't check that I installed it correctly with an app or PC connection.

Thanks!