bms settings

Hi all,i have a homebrew 9p 13s homebuilt pack with an llt smart bms,the parameter settings on the app are many ,can someone write a guide/explanation what each setting is for and what it does,also basic settings for different battery chemistrys,i have looked but found nothing,any help on the app is in chineese,sure lots of folks could make use of the settings explained.

Can you list the parameters?

For 13s, the maximum charge voltage would be around 54.6v so you want the OVP to be just slightly higher than this.
If you discharge to 3.0v/cell, that would be 39v.

There is usually an "engage" and "release" setting for each voltage.

There should also be a setting for the maximum current, which needs to be a little higher than your controller will max out at.

https://drive.google.com/file/d/1Ku_Agk5AGtDXHJRp0XBT9JVRPContOW6/view?usp=sharing
This is the last version that has all the settings in the app, in English

https://drive.google.com/file/d/1a8Chi8l648wrgQWpD-sWuWmbq4pb1Hb1/view?usp=sharing
This newest version looks more modern but has less features from what I've heard.

i already have those,its not what i asked tho thanks but not any help.

uuum you said it was in Chinese so I thought you might have a different version installed.
On my app all the ? bubbles are in Chinese and English.
Also the app gives you basic parameters when tapping the relevant battery chemistry boxes at the top of the settings page.

Very unlikely someone will write up a manual for you.

Make a spreadsheet to list them and to collect notes.

Skip those that are obvious, then pick 2-3 you think are important.

Google to figure stuff out for yourself AMAP

Post your understanding here, proposed values for your context, and ask a few succinct specific questions per post.

There is fairly standard nomenclature for the parameters. If you can list what they call them, I may be able to translate what it means and where you should set them.

right heres the settings i have,this is for a normal lithium ion-colbalt pack not fifepo4,my settings in brackets as currently set
1.overvoltage(4.2)
2.overvoltage rlease (4.199)
3.undervoltage (2.75)
4.undervoltage release (2.85)
5. discharge current (50)
6.cycle capacity (16ah)
7.nominal capacity (15.3)
8. charging duration (100)
9.open balace (close)*
10. balance mode (charge balance)
11.balance turn on (3.7v)*
12.balance precision (0.03v)
13. advanced protection parameters ,hardware over current (390.00A)
14. hardware short circuit (665.00A)
its mostly the ones with the asterix at the end that im unsure about that i need explaining,cheers m3vuv.
at the moment the small ballance symbol isnt comming on next to the battery groups,the cell group voltages are
1=4.110v
2. 4.128v
3.4.108v
4. 4.085v
5.4.117v
6. 4.085v
7. 4.099v
8.4.105v
9.4.121v
10.4.118v
11.4.131v
12.4.117v
13.4.119v
do any of these settings need tweaking,as far as i know the pack is about 17ah but put 15,thought that would give me a better warning when it was nealy flat,ie discharger.

also i noticed my charger has cut off but the pack voltage is only 53.43v,does my charger need adjusting or is it my bms settings?.

OK, that looks like what I would expect.

Most of them are typical values for Li-ion chemistry. The balance turn on voltage is where the balancing function will start working during charge. This is probably a good value.

I'm not sure about the open balance. My guess would be it gets disabled when you select (open), so (close) should be the correct setting.

The hardware over current setting is pretty high. You want this to be higher than the current limit on you controller by maybe 1.5x.

I'm not sure what the charging duration units are. This may be a time limit on charging to stop charging after a set time as a safety feature. You might see if you can increase the value. 100 minutes would seem too short, but 100 hours would be too long.

Choosing a slightly less than rated nominal capacity is what I do also. I like having a little safety cushion in the SOC reading and the pack will lose some capacity over time.

Your cell voltages are not too far out, but more than 0.03v. You may need to discharge and charge the pack a few times to get this closer.

yup ok but my only concern is tho it never gets too 56.4v before the charger cuts off and turns too green.

the charger is set to 54.6v at 5 amp,is that ok?,or the ampage to high for it to balance?

Don't go over 54V for good longevity.

More importantly, don't let them sit long at high SoC, only fill up when ready to head out

i know that,i need to know the answer to what i asked,ie why wont it reach 56.4v before the charger cuts off,as is folks are just repeating what i already know and not what i asked ok.

With the given settings, the BMS will trip around 54.6v. You should set the charger slightly below this so the charger can determine end of charge and not let the BMS trip.

so how do i tell if its the charger tripped or the bms?,the charger cycles from red charging to green about every 10 seconds then charges for about 3 seconds then goes green again for about another 20 seconds and repeats,is that normal?.

When the bms trips, the charger should behave like it's unplugged from the pack. If it cycles on/off, I would guess it's trying to balance the pack, but that's just a guess.

Does your charger have a way to adjust the voltage? If so, you could try lowering the voltage and see what happens.

yes i can adjust both voltage and current,cant see how that will help except charge the battery to a lower soc?

If the voltage setting is too high, the BMS will trip before the charger turns off. You really want the charger to turn off before the BMS trips. 54.6v is the highest you would want to go. It's better for cell life to charge to a slightly lower voltage. I would try 54.0v. You don't sacrifice much capacity by charging to the lower voltage.

You could try it and observe the charger behavior.

m3vuv said:

yes i can adjust both voltage and current,cant see how that will help except charge the battery to a lower soc?

Click to expand...

Your DIY 9p13s battery is worth some TLC to keep your battery in good stead as long as possible. Adjusting the charge voltage cut-off and charge current rate is IMPORTANT for achieving extended cycle life longevity. The difference between FULL or 90% and LVC at 3.10V or 2.90V is only a few more minutes (with med-high speed) of extended ride time; while diminishing the number of your battery's useful c/d cycles.

m3vuv said:

i know that,i need to know the answer to what i asked,ie why wont it reach 56.4v before the charger cuts off,as is folks are just repeating what i already know and not what i asked ok.

Click to expand...

You'll get more cycle life out of your 9p13s battery if you only charge it to 90% (4.10v/cell). Likewise, you'll also extend the usefull life of your battery with LVC at 3.10V/cell instead of say 2.90V.

m3vuv said:

the charger is set to 54.6v at 5 amp,is that ok?,or the ampage to high for it to balance?

Click to expand...

Again, for usable c/d cycle life longevity charge your 9p13s to 53.3V(4.10V/cell) with LVC at 40.3V{3.10V/cell). Whenever possible (TLC) use a 3amp (or evern 2amp) charge rate instead of a 5amp charge rate.

m3vuv said:

also i noticed my charger has cut off but the pack voltage is only 53.43v,does my charger need adjusting or is it my bms settings?.

Click to expand...

53.4V is AOK :thumb: ... being 9p there should be no reason to charge 100% (FULL) or LVC as low as 2.90V.

NOTE: The above replies have been expressed in one way or another already. Sooo the above are just reaffirming what has already been posted in so many words ... sometimes repetition isn't bad if it gets the point(s) across ...

PS: (FWIW) ... My Biogest C1 Pro (13s) comes with a 2 amp charger ... i'm retired so in no hurry. The plastic charger case (with vents on each end and cooling fan) says the cut-off voltage is 54.6V. However, after reaching 53.4V the green light never came on after another 40 minutes and stayed at 53.4V as if that was the actual cut-off voltage. No problem as i only wanted/needed a 90% charge. There is no Trim Pot voltage adjustment on the circuit board. If there was and it charged to 54.6V i would have adjusted it so cut-off was at 53.4V.

> usable c/d cycle life

what is c/d in this context?

john61ct said:

> usable c/d cycle life

what is c/d in this context?

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Think it may have been you that once told another member that a "cycle" includes both the 'c'harge and 'd'ischarge as one complete cycle. Apparently some mistakenly think that it's two cycles ... what? - so they can make believe their battery has twice the cycle life :wink:

m3vuv said:

... need to know the answer to what i asked,ie why wont it reach 56.4v before the charger cuts off,as is folks are just repeating what i already know and not what i asked ok.

Click to expand...

Assume you've used your DMM to measure your Chargers' voltage at output plug ... is it at least 56.0V? If your Chargers' green light comes on at 53.43V you need to adjust the voltage Trim Pot higher IF 53.43V (90% charge) isn't enuf juice for your biking/liking.

m3vuv said:

... at the moment the small ballance symbol isnt comming on next to the battery groups,the cell group voltages are
1=4.110v
2. 4.128v
3.4.108v
4. 4.085v
5.4.117v
6. 4.085v
7. 4.099v
8.4.105v
9.4.121v
10.4.118v
11.4.131v
12.4.117v
13.4.119v

Click to expand...

4.131V - 4.085V = 0.046V ... is it possible your BMS doesn't balance the thirteen 7p-groups any closer than 50mV from each other ... when charging at 5amp rate?? Next time change the charging rate to 3amps once pack voltage reaches 48.0V (3.70V/p-group) to see if the thirteen 7p-groups are then balanced within 30mV of each other.

You're smart enuf to figure out the problem(s) with some step-by-step testing to identify the exact problem(s) ... :thumb: