bluetooth BMS?

[ElectricGod]

after 3 battery cycles of satisfaction, the BMS does not accept load anymore:
it powers off as soon as load is applied and an "IC front-end error" appears in the event log...
does anyone knows what that is ?

what BMS and what cell count? Can you show the log?

 

[made_in_the_alps_legacy]

after 3 battery cycles of satisfaction, the BMS does not accept load anymore:
it powers off as soon as load is applied and an "IC front-end error" appears in the event log...
does anyone knows what that is ?

what BMS and what cell count? Can you show the log?

It is the 18s version of the BMS sold by BMS battery :
https://bmsbattery.com/bmspcm/834-smart-bms-10s13s-60a-with-blue-tooth-android-or-ios-app.html

 

[flippy]

looks like it lost the ADC at a channel after a short or somthing.

does it still display the voltages correctly?

 

[made_in_the_alps_legacy]

it showed up after a long offroad downhill so I won't be surprised to see mechanical damages...

the informations given by the app are all correct in static conditions,
only when I apply load (bike suspended and wheel spinning free), I get many protections activated after some attempts (charging overcurrent times x2, cell overvoltage times x13, cell undervoltage times x16, pack overvoltage times x8 , pack undervoltage times x2 , I have seen voltages jumping from 0.01V to 20...V / cells at the "battery state" page during attempts- and I see the "discharge low temperature times" x4 ? …wonder which protection comes first...

Thxs for ur support, I will inspect carefully when I get motivation back Hope it's only a temp sensor which got disconnected ?

 

[flippy]

i think a overvoltage occured and blew the arse out of a ADC. that usually results in weird voltages being recorded and triggering the bms into a fail mode.

 

[ElectricGod]

I don't think that's the case...It's possible that an ADC failed, but I think it's an incorrect setting in the BMS.

I got that message on one of my BMS. I had a setting wrong that created a conflict. We need to see all of his settings. It was a couple of months ago, but I got that exact message in the log and there was a conflict between 2 settings. I don't remember what it was now.

Anyway, post all of your settings page.

BTW...the 16S through 20S versions of this BMS are all the exact same BMS. The only difference is some solder jumping across a couple of balance pins in the second connector and a small change in the settings done from the PC app. See those bridged pins covered in solder at BC12-14 and BC17-19? In this configuration, it makes this BMS 16S. Undo the left most solder bridge (BC12 to BC13) and now it's 17S, the next (BC13 to BC14) and it's 18S and so on. 20S is no solder bridges.

Then, change this one setting in the PC app. Pack Num which is found in the Other Settings pane, defines the number of cells the BMS detects.

 

[made_in_the_alps_legacy]

sorry, maybe I was of topic :
my battery is made of 3x16Ah 6s LiPo pack. Tonight I plugged other 3x5Ah 6s LiPo pack and could load to 2kW w.o issues, I think the BMS is OK.
EDIT : just saw your post, ElectricGod, I will keep an eye on possible setting conflict and let u know if I can't sort the matter out, thxs for the 18s … 20s explanation

EDIT 2 : I was wondering how to reset the protection log, I also had 0% shown at the dashboard while the pack was charged. I tried a "dummy" battery capacity (0,1Ah) - submit - then tried the known battery capacity (16Ah) : now the dashboard shows 100% capacity and the protections went all back to 0 - any other way to reset the protections count ?

EDIT 3 : btw, what to look at if I want to activate regenerative braking on my CA with respect to that BMS ? (my charging port and port to the controller are separated)

 

[parabellum]

Is there any 4S BT BMS capable of 300A peak somewhere? The idea is to use it for LiFePO car starter battery and need to have adjustable LVC and common charge/discharge port.
Is there any mod to use 8-24S BMS for 4S?

 

[flippy]

dont, it will end in tears.

just use individual balance boards to keep them on the level during engine one and nothing more. you dont want a bms on a starter battery.

 

[ElectricGod]

Is there any 4S BT BMS capable of 300A peak somewhere? The idea is to use it for LiFePO car starter battery and need to have adjustable LVC and common charge/discharge port.
Is there any mod to use 8-24S BMS for 4S?

4S..LOL...Uhhhh no...not likely, but there are balance boards that will do what you need.

 

[parabellum]

you dont want a bms on a starter battery.

Not really, I would just do the rest of electronics but in our paradigm everything including starter is tied to ground in a car and BMS is interrupting negative.

4S..LOL...Uhhhh no...not likely, but there are balance boards that will do what you need.

Balancing is good but my idea is to set LiFePO battery to some LVC level where reserve for starting engine is still there. If I get my battery flat to this level everything shuts down, then I can reprogram BMS LVC down via BT (or just have mechanical short switch) to start the engine and set back to value with reserve after engine runs again.

There are 4S BMS's that can handle up to 560A bursts and 200A continuous, but not programmable and main goal is lost, the battery will be super flat at LVC.

 

[flippy]

You need to set up a accessories battery and a separate starterr battery. That way you can always start even if you drained the acc battery complelty.

 

[parabellum]

You need to set up a accessories battery and a separate starterr battery. That way you can always start even if you drained the acc battery complelty.

Looks like difficult, common ground is negative and screwed on the chassis all over the place, I must isolate all starter related electronics to the other battery. It is easier to have a 4S lipo brick in the trunk, works every time.

 

[flippy]

No, you use a isolation transformer.
And you change the positive, not the negative.

Plenty of guides on the intertubes on how to do this.

 

[parabellum]

I will probably quit if cant do something the exact way I want to. 4S lipo in trunk is the way to go I suppose.

 

[ElectricGod]

I will probably quit if cant do something the exact way I want to. 4S lipo in trunk is the way to go I suppose.

Isn't that a bit high for a typical car? 4S is 16.8 volts. Cars typically run at 13.8 volts and at 4S that works out to 3.45 volts per cell. At 3S and 13.8 volts, that's 4.6 volts per cell...worse! LOL! I don't know about your car, but maybe it runs a bit hotter than 13.8 volts? My Expedition runs at 15.2 volts and a lot of the plug-in USB chargers burn out in it. Still, that would work out OK at 3.8 volts per cell.

I don't know what kind of weather conditions you have where you are, but LIPO really sucks in the cold. Consider looking at LTO. They handle the cold far better than any other lithium battery and they take 10,000 charge cycles. This is a friend of mine in Minnesota. I believe he's running LTO's as car batteries and uses them in his GEM's too. Look up INWO on ES...same guy.

https://www.ebay.com/itm/Sale-12v-mini-ammo-can-battery-11ah-6s-lithium-titanate-lto-lito-As-Is/232643685961?hash=item362aa4ee49:g:qUcAAOSwkvdaaosv

 

[flippy]

engine on is usually 14.2~14.4V. if you have that smart alternator rubbish it will drop to 14ish after a while. but still, complely out of range of any regular 4.2V lipo.
lifpo4 is certainly possible and is what i have in my transit, but considering the huge currents drawn by stuff like the starter that draws 400A inrush and 120A when running i just use a simple lifepo4 balance board to keep the cells kinda balanced out. it doesnt matter if it takes days to balance in a car.

 

[parabellum]

Isn't that a bit high for a typical car? 4S is 16.8 volts

I only use 4S to jump-start the car, so I do not have to wait at all.
When using 3S, you need to wait for a minute to raise starter battery voltage and have some useful energy on starter battery side, with 4S it is start able right in the instant you connect the brick.

 

[flippy]

Or just buy a half-decent starter battery that can actually start the car?

Just saying....

 

[eee291]

Subbed

 

[parabellum]

Or just buy a half-decent starter battery that can actually start the car?

Just saying....

My battery is always top notch, last time I needed to jump start my car, was ~5 years ago and not because of bad battery, but because someone wanted to listen music all day long, on the beach, with engine off. But I did jump start anyone’s else with lipo brick dozens of times after that.
The post traumatic has created an feel of unsolved (probably non-existent problem) somewhere deep in my head. And than it woke up few weeks ago, someone unsuccessfully tried to pry open my brother cars bonnet to take the battery, there where several batteries stolen same night on this street. LiFePO can be relocated to somewhere in the salon because of size and no gassing and solve my PTSD along the way.

Now, more on topic issue:

I ordered 150A 8-24S BMS on 2nd June by slow boat at Ali IC GOGOGO Store, and provided tracking sill can not be found
Then I ordered 300A 8-24S BMS on 8th June, same store but with DHL and guess what, the provided tracking number is not found by now.

I am first time buyer on Aliexpress, is this situation normal or should I start writing letters to the seller?
Maybe I did something wrong and they wait for some info?
I just chose the model and shipping I wanted and made a purchase, without note.

 

[ElectricGod]

Or just buy a half-decent starter battery that can actually start the car?

Just saying....

My battery is always top notch, last time I needed to jump start my car, was ~5 years ago and not because of bad battery, but because someone wanted to listen music all day long, on the beach, with engine off. But I did jump start anyone’s else with lipo brick dozens of times after that.
The post traumatic has created an feel of unsolved (probably non-existent problem) somewhere deep in my head. And than it woke up few weeks ago, someone unsuccessfully tried to pry open my brother cars bonnet to take the battery, there where several batteries stolen same night on this street. LiFePO can be relocated to somewhere in the salon because of size and no gassing and solve my PTSD along the way.

Now, more on topic issue:

I ordered 150A 8-24S BMS on 2nd June by slow boat at Ali IC GOGOGO Store, and provided tracking sill can not be found
Then I ordered 300A 8-24S BMS on 8th June, same store but with DHL and guess what, the provided tracking number is not found by now.

I am first time buyer on Aliexpress, is this situation normal or should I start writing letters to the seller?
Maybe I did something wrong and they wait for some info?
I just chose the model and shipping I wanted and made a purchase, without note.

contact the seller. People I know have had good results from IC GOGOGO.

 

[avoleoo]

I have a question to Smart BMS owners about balancing. Let's say I set BMS balance voltage to 4.05V but charge the battery to 4.2V, is it going to always bleed down all cells to 4.05V or is it going to balance as long as it's charging? Either way if charger will be set at 4.2 v per cell BMS will try to bleed cells down to 4.05v while charging?

 

[flippy]

no, balance voltage is where it STARTS balancing. before that it doesnt do anything. as soon as a cell hits that voltage and the difference is bigger then the set voltage the bms will simply take the lowest cell and start getting all the cells that were above that to get them down to the lowest cell, it wont go lower then the lowest cell. so it continues to charge until the charger tops out.

generally you want to start at 3.8V depending how fast you charge. but 3.8 is a good start.

 

[avoleoo]

awesome, thank you!