2010 precedent leaf install-

[bronsonj]

What do you have your max V set to in the controller? I was thinking of lowering my Max V to be just above the max V I have when my pack gets off of charge. Thereby thinking the controller would not try to charge the pack if the V became too high. Well, I charged only to around 56.5 or so V, well below the 57.6V max and my cart would go sometimes and other times just sit there and shudder. I plugged it back in to my laptop and set the max V to 62V and the cart runs great again.

[cmysstailights]

I have had my cells a lot more out of balance. Takes some time but now she is perfect. My bms is zeva, in time it should balance out.

Sent from my SM-G960U using Tapatalk

[jeffro22]

Originally Posted by cmysstailights

I have had my cells a lot more out of balance. Takes some time but now she is perfect. My bms is zeva, in time it should balance out.

Sent from my SM-G960U using Tapatalk

good to know, thanks

Originally Posted by bronsonj

What do you have your max V set to in the controller? I was thinking of lowering my Max V to be just above the max V I have when my pack gets off of charge. Thereby thinking the controller would not try to charge the pack if the V became too high. Well, I charged only to around 56.5 or so V, well below the 57.6V max and my cart would go sometimes and other times just sit there and shudder. I plugged it back in to my laptop and set the max V to 62V and the cart runs great again.

Not sure what controller is programmed to. Will have to check some of those settings again . I am pretty sure I bought it with close to stock setting. Was running it on fla batteries for a month or 2

Had a bms issue a couple days ago. Trying to decide what to do now.

[jeffro22]

Had an issue with my BMS, It pretty much melted on me.

I Have used the cart 2-3 times since install and thought I had it operating correctly. Had adjusted several settings per Jasons @chargerys suggestions

So after riding about 5-10 minutes I stopped the cart and after maybe 1-2 minutes of the cart sitting an alarm started going off on my bms. I checked BMS display and it was showing a cell voltage difference of 400mv and i could smell something burning. lifted the seat and checked BMS screen. (i had alarm set to sound at anything greater than 300), my pack was reading 57.07 and Specifically one cell was showing overvoltage @ 4.27 v, which seemed strange bc my pack was lower when I started the trip and my high cell v before this trip was 4.11. ( i had my HV cutoff set at 4.12 per cell, which i see should probably be set a little lower)

I looked at the pack for the burning smell noticed my BMS was extremely hot. I immediately unplugged the bms wires. I was able to get a voltmeter within maybe 10 mins and I checked pack voltage and it was reading closer to 56v, so I am pretty sure it was false readings from BMS

trying to figure out what caused this . I dont know much about the regen brake system - is it possible this was a true overcharge from the regen system, or do I possibly have something else going on, or is it most likely a BMS failure, (either faulty or caused by improper installation)

I am thinking this is just a bad bms which caused faulty readings.. The only other thing that is strange is I have really made 2 short trips with the cart since the swap and the first trip I had my main MZJ400 solenoid fail. I swapped out and cart was operating fine, but not sure if I have some other electrical issue causing these failures.

I did bypass the LV cutoff and drove cart home with BMS disconnected, and carefully watched voltage the whole time and it stayed between 53-56V while driving . (not sure if this was smart but felt it was ok since Voltage was in spec)

I opened up bms and circuit board is burned. Jason with the chargery says I caused damage when I hooked up the display monitor to wrong Communication port when I first installed unit and isn’t covering under warranty. If I caused damage I am ok with this. Any thoughts? I ordered another chargery unit since I already have everything else in place but worried maybe this will happen again

I know I should have followed one of the builds exactly and probably used a Zeva BMS, but when i first researched this last year I didn't think there was any issue with using either system and started purchasing the needed items as I found them. I think the BMS was first item I purchased. I thought the BMS installs would be very similar and never thought to look at chargery website for install instructions (no instructions came with the unit itself).

SO to clarify, I definitely had some install missteps , I initially I installed shunt in wrong location (+line instead of -), used 48v relays for HV/LV instead of 12v used by chargery. I also had plugged in the monitor to wrong port. I Never used the cart like this, and corrected the issues, but BMS was powered from battery taps.

[Sergio]

That was unfortunate and it could definitively be caused by the Regenerative current.

The thing to remember about that chargery BMS is that the "discharge" relay output is only disabled when the cell goes under voltage.

Unless both relays (charge and discharge) main posts are wired in series, the Chargery BMS cannot prevent an over voltage caused by the Regen brake.

The relay drive output is also only 12v so I am not sure how you got the 48v relay wired.

The current shunt placed on the positive side instead of the proper negative side could have burnt that voltage sampling chip, but if it had done that your display would not have shown any current.

The best (really only) way to prevent a Regen overcharge from disabling the cart is to program the maximum voltage on the Controller (available on Alltrax Controllers) to just below the maximum pack voltage.

[jeffro22]

thanks for the reply. Really appreciate the help

to clarify, I never had power through the shunt when I incorrectly wired it on B+ side. I moved the shunt to the B- prior to getting correct disconnect installed so my 57V was never getting past the first main relay . directly Prior to bms failure , i did calibrate shunt current following video provided by chargery. Maybe i did incorrectly??


I do have the alltrax500 controller so I will plug into my alltrax and set overvoltage. what is safe setting? If i reconfigure BMS/charge settings to 56v full voltage would I set the alltrax slightly higher? 56.4?

ALso, As you mentioned my current HV relay is a small relay that only disconnects the charger if overvoltage. Would I be better off getting a 2nd Large disconnect and wiring it in series? I didnt do this bc I didnt want to add another failure point to the system


also, you had asked how I wired a 48v relay originally. I had tried to use a MZJ400 48V solenoid but it wouldn't operate bc the coil voltage wasnt correct. So when I first installed my setup, I had MZJ400 about 8 inches after battery pack and I never got power past it. (i think the zeva uses 48v , but chargery uses 12 v coil) I swapped this out for the 500amp, 12v relay Shown below, which seems to operate correctly . it will connect and disconnect the pack power at BMS settings. I had the mzj400 installed same way

[Sergio]

As far as the shunt since the BMS could still measure current then everything was fine there.

One way you could convert that setup you have using the existing parts to work with a Sepex (Regen) cart is to use the small 12v relay connected to the BMS charger control to interrupt the coil current of the larger 12v discharge Solenoid.

The charger positive output wire would have to be connected to the Solenoid big post on the Controller side.

That way either the LV or HV BMS output could disable the power In/Out of the pack.

Your charger should stop on its OWN without any involvement from the BMS

The only time the BMS should engage is when a cell is out of range, not during normal charge/discharge.

Example:

Charger set to 4.10vpc or 57.4v (14 cells pack)
BMS HV set to 4.18vpc
Controller Max Voltage set to 58.2v (Approx 4.16vpc)

That way you have some room left after a full charge to accept Regen current and the Alltrax Controller will automatically reduce the Regen brake intensity as the voltage approaches the 58.2v

If any of the cells is way out of balance and gets to 4.18v, the BMS will shutdown the cart.

I personally don't like using Solenoid/Contactors to disconnect the pack, that can be an issue with the Alltrax Controller when it happens during a Regen event and that is why on my setup I use smaller relays to disable the cart control.

[jeffro22]

Sergio- Thanks again for the write up, I truly appreciate the help!

. I think I understand the new relay setup and I like it alot better than installing another main disconnect/relay.

Ill probably post up a sketch to make sure i have new setup wired correctly.
Also, I plan to hookup laptop to the alltrax today to see what current settings are. will post back findings

[bronsonj]

Originally Posted by Sergio

Your charger should stop on its OWN without any involvement from the BMS

The only time the BMS should engage is when a cell is out of range, not during normal charge/discharge.

Example:

Charger set to 4.10vpc or 57.4v (14 cells pack)
BMS HV set to 4.18vpc
Controller Max Voltage set to 58.2v (Approx 4.16vpc)

That way you have some room left after a full charge to accept Regen current and the Alltrax Controller will automatically reduce the Regen brake intensity as the voltage approaches the 58.2v

If any of the cells is way out of balance and gets to 4.18v, the BMS will shutdown the cart.

I personally don't like using Solenoid/Contactors to disconnect the pack, that can be an issue with the Alltrax Controller when it happens during a Regen event and that is why on my setup I use smaller relays to disable the cart control.

I think this should be a sticky!

[jeffro22]

finally got laptop hooked up to the alltrax.

My settings were set as follows.

LV - 38.5
HV -62

I changed to 49 lv and 58.2 HV- Wasnt sure what the safe LV would be? I remeber you saying I need the alltrax setting slightly ahead of were the bms will engage disconnect, so ideally the alltrax will limit voltage, and BMS will be a backup safety

Noticed a check box on the main page that says "use with bms" I left it unchecked.

also, on main alltrax settings page, is there anything else I need to adjust with these settings

max regen armature amps 45.1

Max regen battery amps 45.1

plug braking current 250.1