Sorry I didn't get back to you sooner but I live in Nebraska and the weather here has been cold and rainyFirst check to see if any of the connections are getting warm
Then I would drop the 112v down to 100v - just to see what is happening
Does your BMS tell you if any cells are collapsing under load?
I use a
http://www.evdl.org/pages/battbridge.html
Cheap as chips and it will tell you if you have something wrong under load
I did drop 112v to 100v and it did seem to help but the BMS still alarmed just at a higher amp draw around 132amps instead of 100ampsSorry I didn't get back to you sooner but I live in Nebraska and the weather here has been cold and rainy
I put the truck up on jacks and ran the motor while the BMS was in alarm mode and felt the connections on the controller shunt and contactor none of then were warm
I am not sure if the BMS tells me if a cell was collapsing under load of not or how to look for such information
I will attempt to attach an file from the Soliton Jr while it was running so you can see what is going on while it is alarming hopefully this will help
My BMS system pre-dates the BMS system you described, mine has green LEDs that stays on constantly, I jacked up the truck and had a helper run the accelerator until the BMS system was in alarm while I watched the whole battery pack BMS's one green LED went dark and when the alarm went off it lit up again, so I am assuming that cell is bad and needs replaced right?The miniBMS celltop boards have LEDs which blink at different rates depending on their status and history. If one of your cells is bad, and causing your BMS alarm to trip, that cell will go into "long pulse" LED flashing mode:
http://cleanpowerauto.com/files/MiniBMS V3 User Manual - Distributed.pdf
If you see that one cell is sagging badly and tripping the low voltage cutoff BMS alarm during load, you need to pull over and look at all the celltop boards immediately- you'll quickly find the cell or cells at fault. Bypass that cell- take it out of the pack circuit- and see if your problems persist. If they don't, you're golden. If they do, and a different cell goes into LVC, you may have been sold some bad batteries...
I did as you instructed and checked the voltage while the BMS was alarming and the voltage was 2.09 so I removed the battery cell and jumper to the next battery cell and did a hard acceleration to see if the BMS alarm would but it did not so I am thinking you solved the problem, I will buy another battery but I am surprised this is the second battery I have has to buy and I have yet to have the truck on the road what's up with that?Sounds about right. What you want to do is to hook up a voltmeter to that cell only and watch it while you accelerate hard. If it drops below 2.5 V, that cell has developed high internal resistance and needs to be replaced. For the timebeing you can just remove it from the pack circuit, installing some longer jumpers to jump around it. If you drive and can hit higher currents without causing another cell to go into BMS alarm, you've solved your problem, and you can decide whether or not you really want to buy one cell to replace the bad one.
But you have to ask: what killed that one cell? And whatever did, is there any risk that it killed or weakened others too?
Don't panic: I had one 180Ah Sinopoly cell just gradually lose capacity over time. It was leaking electrolyte vapour out of its vent- I suspect it just wasn't made properly and had a defective vent valve. Otherwise, this cell was perfectly fine- it charged and discharged without causing any problems- it just eventually fell to a capacity of 135 Ah, which I discovered on a long drive one day when my BMS alarm went off. I've replaced that one cell and all the others are just fine. About once a season I make sure to drive the car carefully around the neighbourhood after a long drive, to find out where the "bottom" of my pack really is. My pack is top balanced more or less, by the shunt charging feature of the BMS. I don't suffer over getting the top balance perfect, and just let the BMS trip the charger when any one cell gets to HV cutoff. I have installed six little voltmeters just for convenience, which I can turn on with a pushbutton switch. They compare groups of 5 or 6 cells to one another. I check them at both the termination of charge and after a long drive and record the voltages in my logbook. This allows me to watch for any problems.
Are you sure your pack was initially balanced? Is it possible this cell was sagging and alarming because it was already empty? Was its unloaded voltage the same or less compared to all other cells?I will buy another battery but I am surprised this is the second battery I have has to buy and I have yet to have the truck on the road what's up with that?
You were right about what caused the BMS system to alarm I got a new battery cell and charged each cell all 45 cells one at a time to make sure the battery pack was balanced including the new battery cell then installed the new battery cell and test drove the truck and no BMS alarm great! Now can you tell me how to install a proximity switch to my Soliton Jr. to act as a tack I just want to make sure I get the wiring right so I can finish this project.Sounds about right. What you want to do is to hook up a voltmeter to that cell only and watch it while you accelerate hard. If it drops below 2.5 V, that cell has developed high internal resistance and needs to be replaced. For the timebeing you can just remove it from the pack circuit, installing some longer jumpers to jump around it. If you drive and can hit higher currents without causing another cell to go into BMS alarm, you've solved your problem, and you can decide whether or not you really want to buy one cell to replace the bad one.
But you have to ask: what killed that one cell? And whatever did, is there any risk that it killed or weakened others too?
Don't panic: I had one 180Ah Sinopoly cell just gradually lose capacity over time. It was leaking electrolyte vapour out of its vent- I suspect it just wasn't made properly and had a defective vent valve. Otherwise, this cell was perfectly fine- it charged and discharged without causing any problems- it just eventually fell to a capacity of 135 Ah, which I discovered on a long drive one day when my BMS alarm went off. I've replaced that one cell and all the others are just fine. About once a season I make sure to drive the car carefully around the neighbourhood after a long drive, to find out where the "bottom" of my pack really is. My pack is top balanced more or less, by the shunt charging feature of the BMS. I don't suffer over getting the top balance perfect, and just let the BMS trip the charger when any one cell gets to HV cutoff. I have installed six little voltmeters just for convenience, which I can turn on with a pushbutton switch. They compare groups of 5 or 6 cells to one another. I check them at both the termination of charge and after a long drive and record the voltages in my logbook. This allows me to watch for any problems.
Tach? Tachometer?nd no BMS alarm great! Now can you tell me how to install a proximity switch to my Soliton Jr. to act as a tack I just want to make sure I get the wiring right so I can finish this project.
I meant to say Tach the Soliton Jr. has a Tach terminal and recommends using a three wire proximity sensor, I am so close to be done I just don't want to make any mistakes now on wiring it in.Tach? Tachometer?
