by pass a BMS that may be the cause of issues

[beoutside]

I think I have a compromised BMS unit on my CALIBIKE brand battery, since I run a CA v3 can I use its limiting parameters and just bypass/remove the BMS from my battery pack?
I think this has been an issue since day one and I should just have returned it.... thats on me. I believe what it has caused is low amps out from the battery only seen on hills and windy days.
Charges and discharges fine , I think, showing full volts on the CA when charged. for more info see my posts .
Appreciate it

 

[beoutside]

Upon further inspection I think I ask calibike for another BMS that just plugs right in thanks !

 

[teklektik]

Ya - a replacement from them would be the best if possible.

Although there is a lot of quick advice here to pull things apart, etc, I'm a big believer in giving the vendor the opportunity to make it right. In your case, even though it's been awhile, couching it in terms of having done everything possible to avoid returning it as well as the difficulties in shipping batteries, may make the best case for a replacement BMS.

 

[beoutside]

Appreciate it and agree with those thoughts . I contacted them and offered to buy a new BMS and the response was they would be more then happy to load test it. They also commented the BMS would either work or not work so either 0 or 30 amps and since I tested the system without the CA it must be the controller. Anything is possible but it does look like some of the electronics are compromised on the BMS and since I have never built a BMS from scratch I am not sure what that means .
On my Battery there is a main red coming from one corner of one of the battery cell/strips, at the other end of that row underneath is a main black that has a Andersen pole connecting to the BMS, the opposite side of the BMS has the other main black. As that ground comes off the BMS it has a solder connection then goes to my ground of the xt 90 anti spark that powers my controller. So I could by pass the BMS by creating a Andersen pole ground that would connect directly from the battery to my ground on the xt 90. I did test this for power and it shows full voltage . The smaller white wires that are soldered from each battery row into a plug for the BMS run charging as you suggest. Great tips thanks .

 

[beoutside]

Some pics thanks

 

[beoutside]

Just confirming how my 7 parallel 13 in series relates to my battery set up parameters on my CA V3 input for string numbers ? Thanks thinking 13 didn't want to assume.

Battery Model 48V15T
Voltage (V) 48
Capacity: 15AH
Type: Li-Ion 18650 cells
Brand Name: AODA
BMS Rating: 2C
Size: Triangle 10.5″ x 15.0″ x 18.0″ x 3.75″ wide
Weight: 4.5 KG (9.9 lbs)
Cycles 800++
Charger 110V/220V in 48v 4AH out
Source Resistance (mO) <40
Cell Combination 7P13S
Cell Quantity (parallel*series) 7*13
Discharge Cutoff Voltage (V) 37.6
Charge Cutoff Voltage (V) 54.6
Rated Discharge Current (A) 30
Instantaneous Maximum Discharge Current (A) 50
Maximum Continuous Discharge Current (A) 30
Maximum Continuous Charge Current (A) 5
Charge Mode CC-CV
Standard Charge Current (A) 2
Charge Time Standard Charge Current 8
Fast Charge Current (A) 5
Charge Time under Fast Charge Current 3 hours
Charge Temperature Range -20C -55C
Discharge Temperature Range -20C -55C

 

[teklektik]

Just confirming how my 7 parallel 13 in series relates to my battery set up parameters on my CA V3 input for string numbers ?

From those specs:

• Type: Li-Ion 18650 cells
  Batt->Chemistry = LiMn
  
  
• Capacity: 15AH
  Batt->Capacity = 15Ah
  
  
• Cell Combination 7P13S
  Cell Quantity (parallel*series) 7*13
  Batt->String # = 13
  
  
• Discharge Cutoff Voltage (V) 37.6
  Batt->VltCutOff = 13cells x 3.00V/cell = 39V or higher.
  The BMS LVC is rock-bottom low - the CA should prevent you from hitting it.
  
  
• Instantaneous Maximum Discharge Current (A) 50
  Maximum Continuous Discharge Current (A) 30
  • PLim->MaxCurrent = 25A or 30A
    
  • <OR> Use 3-position switch set as 'BikePath, Normal, Boost' with 'Amps Limiting'
    PLim->MaxCurrent = 40A
    Use 'Boost' when you need the power and don't mind pushing the battery hard, otherwise in the other two modes the CA will keep the battery from being flogged.

Also:

• PLims->MaxPower = 9900W (default)
  The CA current limiting does everything you need in this case - no need to invoke unnecessary limiting functionality. The motor wattage has little if anything to do with this setting.
  
  
• Leave the temperature rollback settings at defaults unless you want to lean on the motor harder

 

[beoutside]

awesome going for test ride with bypassed BMC .... and fire extinguisher

 

[beoutside]

No difference with what makes sense to me as a BMC bypass, still won't draw more amps as resistance/load increases be it wind or slight incline, luckily its flat were I use it can't spend any more time on this right now and at least it's replacing a car on errands... will bug you later thanks again !