New BMS

K

kruggy

1 µW
Joined
Sep 1, 2021
Messages
3
I am a newbie and learning as I go so I don't have to pay $900 for a new battery.

My bike was left out in the rain and I think it fried the BMS. I have the battery taken apart and I have tested all the series and they are reading corect voltage so I am assuming there is nothing wrong with any of the cells.. The battery is 13S5p. I ordered the following BMS from Amazon
https://www.amazon.com/gp/product/B...9&pd_rd_w=rTcWX&pd_rd_wg=64Qi1&ref_=pd_gw_unk

I have it wired up however I am slightly confused on wiring the balancing leads. My leads have 1 positive for the whole back and 13 negatives coming from the individual series. Per the lettering on the board, it looks like it is wanting one negative and the positive leads from all of the individual series.

I don't feeling confident dissassemlying the battery back further as I don't have access to the terminals without taking the whole pack apart. The batteries run north and south in plastic honey combs so all the terminals are hidden.

Is there a board that will take the balancing wires as it is currently wired.

Any help would be very much appreciated!
 
Your BMS should have either 13 or 14 sense/balance wires. If it has seven or eight of them, you have the wrong BMS as ZeroEm noted.

The wire on the positive extreme of the multipin plug goes to the pack positive. Then they all wire up in turn to each cell group in sequence. Call them "positive" or "negative" as you wish, but all the in-between connections are both, and what matters is that you have 3-4V intervals between each successive connection. If you only have 13 wires in the plug, then the BMS senses the pack negative from the B- power terminal.

The pack positive output and charge leads attach directly to the cells without connecting to the BMS.
 
The controller is the DAS-kit CT5-15.
https://www.leoncycle.com.au/controller-das-kit-ct5-i5
Click to expand...

Max current is 15 AMPS so I assumed 20 amp bms would be suffiecient. Am I wrong in that assumption?

ZeroEm said:
I'm confused, you have a 48V battery maybe good for what 25-40a max and you're buying a 24V 20a bms?

24V 20A 7Series BMS Protection Board with Balancing for Lithium Li-ion
Click to expand...
Click to expand...
 
Das-Kit Controller CT5-I5 for Moscow, Milano, Miami, Venice

Specification:

Das-kit Controller

Rated Voltage: 48v

Maximum current: 15A

Rated current: 7A

Low voltage protection: 42V
Click to expand...

Yes the max for that controller is 15A it's working as advertised. Rated current is 7A

by kruggy » Sep 01 2021 2:06pm

I think I have it working now but am worried that I have a board that rated for too low of amps. I hope I am alright given the controller is pulling a max of 15 amps

Also I apologize I originally had the wrong link. Here is the link to the board I actually bought.

13S 48V 20A Li-ion Cell 18650 Battery ... UTF8&psc=1
Click to expand...
That link is not working.

https://www.amazon.com/dp/B07DNHBDX...abc_8JMS0PCJJZ2EXFRYCSB3?_encoding=UTF8&psc=1 I trimmed it a bit, should work now.
 
I thought BMS had to match use current.

OP...if instructions are unclear, return item to Amazon for credit...I understand time compression, but it is what it is.

Amazon should issue credit fast.

Wet Electrics are not compatible ever.

I am NooB also, seems we Noobs must scratch for low cost process.

But, you will got good help here, if you are a discerning dodger....
 
BMS are the last thing that should limit power. They should allow the battery's maximum output for a few seconds.

I'm all for saving money. pushing everything to the max every ride is not saving money it called testing. Want to save money buy quality equipment that will meet your demands.
 
by bobbill » Sep 05 2021 2:25pm

+1.
Speed and bullshit kills....

but hard to devine the facts (truth) too often, for us NooBs/
Click to expand...

If they are selling you something it could well be bull. They push max as continuous. You can push everything but need to monitor it for it's limits.

I'm lazy so I have a power switch so I can put it in low and just not worry about it. if its in high need to limit it's use. I have seen people buy the smallest and cheapest and then run them around maxed out. burn up controllers and batteries last less than a yr then complain.
 
Dig that...

Where does one place controller on a longboard?

Is speed maker in-hand and wireless,

Same is "Controller?"

I have made boards but all were manual, FWIW. Curious NooB that I am.
 
kruggy said:
I think I have it working now but am worried that I have a board that rated for too low of amps. I hope I am alright given the controller is pulling a max of 15 amps

Also I apologize I originally had the wrong link. Here is the link to the board I actually bought.

13S 48V 20A Li-ion Cell 18650 Batt...abc_8JMS0PCJJZ2EXFRYCSB3?_encoding=UTF8&psc=1
Click to expand...

I need a 13S Balance BMS, and I like that this one has LED's to show when a cell is off balance, plus I don't have to wait for 2-6 weeks to come from China. BMS rarely control operating current. This one is rated for 20A means that the transistors will pass 20A without getting too hot. Some BMS will shut down if there is short circuit. Some shut down with high current, Probably won't happen with a 20 dollar board,

Current is determined by your controller, and if that is 15A, I think this will be a good match.

Anyway, I'll get the BMS tomorrow. Hope it works.
 
bobbill said:
Doc, link is dead for me...but interested enough to search.
Thanks...
Click to expand...

I think that this may be the correct URL (extracted from previously posted mangled URL):
https://www.amazon.com/dp/B07DNHBDXV
 
Your BMS arrived from Amazon today. It has the same size balance connector as ny current one, but reversed. I cut the ribs off my existing connector and flipped it. Easy install. It's recharging right now.
 
docw009 said:
I cut the ribs off my existing connector and flipped it. Easy install.
Click to expand...

There goes what little fault tolerance it had. Good luck with that. Maybe put a piece of tape over the plug with notes written on it.

I rarely get a replacement BMS that has the same size and pin count plug as the one I'm replacing.
 
Chalo said:
docw009 said:
I cut the ribs off my existing connector and flipped it. Easy install.
Click to expand...

There goes what little fault tolerance it had. Good luck with that. Maybe put a piece of tape over the plug with notes written on it.

I rarely get a replacement BMS that has the same size and pin count plug as the one I'm replacing.
Click to expand...

There's no way to flip the BMS over and put the balance connector in the other way due to the placement of the P-, B-, and C- wires. I am the customer here anyway. And if I did flip it, the LED's wouldn't be visible thru the little glassine window I put in the battery.

I really wanted to get the BMS tested, and soldering 14 balance wires ... that's a fault prone event itself.

Anyway, the battery balanced and the lights went off. This is not the battery I posted about earlier this summer which had one cell group dropped down to 2V. That one is in safe storage, pending a cell group replacement.
 
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