BMS short circuit with Extreme Team and Navitas 600

[shoomba]

I recently have been having issues with my extreme team battery. I installed it earlier this year sometime in the summer, and I installed the controller maybe around this time last year. The issue I have been having is the battery just dying on me and my cart becoming a brick. The BMS app on my phone shows a DisMos short circuit, the only way to recover is to plug the cart in to charge.

I remember after installing the Navitas and still on lead acid, rarely after letting off the accelerator and then hitting it again fairly soon, my cart would drop voltage down to like 35v on my dash meter and kinda shutter for a second or two then come back. I feel like this same issue is happening but now Im on lithium with a BMS that is bricking my cart. When I did the controller install I also did 2 guage wires and HD solenoid(Curtis not the orange one. I didnt put on a resistor as the instructions said not to but I do have the diode on).

Extreme team customer service has not been good. I had this problem back in August and after an email asking if I had the app I got left on read but the cart was behaving so I let it go. It recently happened again and I have reached out twice with no reply. I have an ANT bms in my battery and their website has no info on it, it still claims their batteries have a davy BMS. The problem is so infrequent I would be happy if I was able to hit a button on the app to reset the BMS but the app is literally all in Chinese so I have no idea what to press. I havent reached out to Navitas yet but I will tomorrow.

Anyone got any ideas on what could be going on? I've been thinking of carrying around some kind of portable battery with a wall outlet so I can "jump" the cart but that'll take up a lot of room and dont want too if I dont have too. Ive also been driving around with the regen turned all the way down but I would like to have that its kinda the main way to break when going full speed.

[Pat911]

Looks like you purchased a battery that is incapable of supplying the current required for your setup. You could possibly be able to turn the BMS back on from the app but without seeing it I cannot help you. Look at the app when it's working then again after it trips and see if there's a toggle that has changed. Then see if you can toggle it back.

To fix your problem you'll need to dial down the settings in your Navitas controller to better suit your battery or get a battery with higher supply current specifications.

As for a "Jump Starter" have a look here where I described how you can build one using a car jump starter, no need for a mains outlet...https://www.buggiesgonewild.com/showthread.php?t=186264

Cheers
Pat

[shoomba]

That is another reason I am not happy with Extreme Team, they market the battery as High Output, providing a max discharge of 600 amps for 10 seconds. I have my controller set to 500 max as a precaution to prevent something like this.

As far as the app goes I tried a couple toggles last time when it happened a few weeks ago but its hard to do when all the text in the app is Chinese and they wont provide any information on it.

I did see your post about building a jump starter but didnt fully understand it but it seems like that may be my best option so I may be reaching out in the future. Thanks.

[Volt_Ampere]

It does sound like the controller is drawing excessive current at times which is then tripping the BMS. This isn't a good thing and I don't know how you stop it from happening. You should consult with Navitas about this since the solution will have to be on the controller side of things. Sorry - I have no experience at all with Navitas.

[CP241]

I’d agree with volt here. If you said the voltage dropped to 35v sometimes with lead acid batteries, before lithium, then I’d say the problem is on the controller side. I can’t think of any circumstances the controller should pull that kind of current demand to drop a lead acid pack to 35v without something being defective in the controller or possibly (though unlikely) the motor circuit. Maybe an intermittent dead short inside the motor but I’d think you would have other symptoms if that were the case.

The BMS is doing exactly what it is supposed to… shut down the pack at that low voltage to protect itself.

[WalterM6]

I've had a similar problem. I have a Alltrax Controller and when I stomped the go pedal to go up a hill the BMS shut down due to undervoltage. Particularity during cold weather. The reason I found was due to the turbo mode setting. With turbo selected the controller increases the demand current to the motor causing it to shut down. Like I said I have a Alltrax but Navitas probably has a similar setting. Look in your setting and see if you see anything similar and disable it. And to be completely honest you are expecting to much from a battery that will only deliver max 200A with a 600A controller. You might try dialing your controller back to 300a.
Edit: Your battery might be capable of delivering 600A for 10 seconds but your BMS is only capable of safely handling far less.

[Pat911]

I was unaware that your battery can supply 600A for 10 seconds. That's a huge amount of current. Two things here then, The controller needs to be dialled down as already suggested, or there is a problem with the battery and it is tripping at a lower current than 600A. As Volt_Ampare suggested, reach out to Navitas who might be able to help.

Walter, the BMS is integrated in the battery and sold as a unit. If it is advertised as a 600A peak battery then the BMS should be able to handle the current.

Cheers
Pat.

[shoomba]

Thanks for the help fellas I'll be reaching out to Navitas to see what they have to say. I felt like the issue was more with the regen breaking than with accelerating. I stomp on the pedal pretty much all the time and Ive only had this problem maybe 5-6 times and I dont remember what I was doing in every instance Im pretty sure its almost always after taking my foot off the accelerator and the breaking kicks in and just kinda over does it.

[jasonojordan]

Navitas is very helpful with the settings of things. I would reach out to them via phone and they can help you tweak the settings to match your setup.

Do you have the OTF controller?

[Volt_Ampere]

You may have to dial down the Regen then. The BMS may trigger if the Regen current is too high especially if you have a full charge.