Warning - Allied batteries

scottyb

I got an email from Alltrax support today about a lithium battery problem.
I thought I would share this for your benefit.

(Alltrax) had a couple customers run into issues using the Allied batteries (the self contained lithium 12v cells) and performance controllers. The batteries can’t output high enough current when paired with a performance controller and will cut out/current limit. (Engineer) also told (support) that pairing those cells up with an XCT/SR could potentially harm the motor controller.

My guess is any damage resulting from improper power supply would not be covered under the warranty. I have not seen any of my customers with this problem but I'm not a big lithium proponent as there are no hard established guidelines here.

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

Sergio

That was one of my main concerns about not only those single packs but any other design using a single main disconnect solenoid like the Gigavac with an XCT controller.

If the Solenoid were to open and disconnect the pack during a Regen event, the Controller could blow up as the Regen diode would not have impact to prevent voltage build up.

On a DIY setup you can install an additional "Regen Diode" on the gigavac disconnect solenoid as long as You have another method of shutting down the controller, like cutting the power to the key switch.

scottyb

Your input is always the best here on this stuff. Alltrax has been working on a BMS unit and lithium package for years now. I'm sure they too have addressed these concerns.
My concern with lithium power source is the try and see approach on the forum using batteries and BMS not specifically made this application.

davidgolfer

Thanks for the info Scotty. Will this same problem occur with stock controller I wonder? I was looking at Allied batteries but think I have talked myself into the RoyPow pack

Sergio

Any system that isolates the battery from a Sepex controller during a High Voltage condition can be an issue for a Sepex Controller during Regenerative brake operation.

The OEM controller used a pre-charge resistor on top of the Controller so there was always a "path" for the Regen current even if the Solenoid opened.

Since the XCT did not use a pre-charge resistor they needed a different solution, the Regen diode is installed in a reverse biased position so it only conducts from controller to battery.

In either case the assumption is that the "load" or batteries are always present in the circuit.

BBBHC

Pretty sure I know the answer...but to make sure...

If I have Regen turned off, this is not a concern, correct?

Sergio

Correct, the Alltrax XCT Controller is only vulnerable to "over voltage" during Regen if the battery is disconnected.

Keep in mind that any time the batteries are disconnected by the gigavac solenoid the XCT also resets the pedal calibration values which should not be an issue as long as it is not needed.

I am still playing with the voltage/current settings on my new setup, charging the batteries to 4.05V does not allow much Regen until they drop below 4.00V.

The good news is that the XCT does a great job mitigating all the settings (Battery Regen, Armature Regen, Max Voltage and Throttle rate) so it always works but the brake intensity varies based on the batteries SOC.

plowman

guys i would like to clarify a few things things about this original post the lith pack that tony is talking about is only a 50ah pack with a big motor and controller, i have been testing carts in warm and very cold climates with our riot kit and a hot map with amazing results, and also with 80 amp hour packs with out shut down, and ridicules run times, this email said nothing about the xct controller, if you want no issues and are going to run high amp draw motors and big controllers then run the 80 or 100 amp hr batts! ( email from tony)Carl,
I now have the second complaint from a customer who has a Allied, it is shutting off inadvertently because its way undersized.

This first one has a DCX and D&D motor this new one today has a SPM and D&D. Both are the 50amphr versions. They will drive for a few miles then just cut out.

That’s why system level managed Lithium is the only way to go.

Best Regards
Tony Thorne
Alltrax Inc
Innovative Products Made in the USA
541-476-3565

scottyb

Hi Don, Thanks for your input. You are saying the problem only exists for the smaller packs (50ah) and the larger 80-100 ah packs have a higher C rating compatible with the big motor draw. Correct? Thanks for clarifying

PearlPack

I have a 2012 "PH" Precedent with a stock controller and PQ Bandit. How do I turn off the Regen?