Balance Charger for 10s3p 18650 Cells?

[jose]

I've got a new 10s battery pack (no BMS), but I don't expect to do a lot of balancing. Battery has balance wires in place and would like to occasionally check the 10 series voltages.

The starting price I found on 10 series balancers is $120: while an 8 cell balancers are $30-40. Or did I miss something out there?

Is there a process (method) to balance a 9+ cell battery w/ the 8 (or 6) cell balancer? If not, I assume I could use use 8/6 cell for monitoring using 2 separate measurements?

My fallback method will be wiring a 10-position/2pole rotary switch to connect my multimeter. :wink:

Many thanks for reading!

 

[dnmun]

the icharger 1010 will display the cell voltages so why do you need to use another tool to measure the cell voltages?

do not even understand what this multi position switch is for. how much will it cost?

 

[neptronix]

iCharger 1010b+ is all that you need. A cellLog 8s is nice to use to check things while you are out on the road though.

 

[jose]

Q: Is there a 10s balace charger for less than $120?
A: From replies I'm assuming NO.

Q: Is there a process (method) to balance a 9+ cell battery w/ the 8 (or 6) cell balancer?
A: From replies I'm assuming NO.

My comments to the replies:
CellLog 8s looks interesting.
In that case I would connect my 11 balance wires to TWO identical plugs that mate w/ the Cellog8s; then connect those plugs one-at-a-time to the CellLog 8s taking TWO separate voltage readings?
It would be really nice if Cellog8s had TWO-8cell ports which could be separately selected to avoid disconnect/reconnect between readings. Seems like something anyone w/ more than 8s battery would want?

The rotary switch is a cheaper alternative to the 1010b+; If I paid-up for the 1010b+ I'd have no need for the rotary switch.
Purpose of switch is to select (switch) individual cell voltages to be measured by the multimeter; safer than probing balance wires (risking short-circuits).
The rotary switch may take 2 hours (my labor) to interface balance wires thru selector switch to multimeter. Searching quickly I found a switch for $9 shipped:
http://www.aliexpress.com/item/1pc-11-WAY-11-POSITION-CERAMIC-SELECTOR-ROTARY-SWITCH-D/654266777.html

Something like the Cellog8s looks like a better alternative than building-up this rotary switch. If I ever need to balance, could do manually by connecting load resistor across high voltage cells. Just don't know yet how many charge/discharge cycles my bike is going to have.

Thanks again!

 

[neptronix]

Read my series lipo charging tutorial in the battery section and go from there.

The cell count of the charger is a limit to the amount of cells you can simultaneously charge and balance.

A rotary switch thingy is not the best idea. That sounds like the most laborious way to do things possible ( and error prone )

The price on an iCharger 1010b+ at hobbyking is probably the lowest you will find.

 

[riba2233]

Why not bms + standard charger? It will be hassle free and much cheaper than $120.

 

[docnjoj]

12S Thunder Charger is less than $100 at Hobbypartz in the USA. It will certainly balance 10S.
otherDoc

 

[riba2233]

Still more expensive then charger and bms, and isnt hassle free.

 

[999zip999]

What 10s3p battery ? More info. Plus what controller and motor will this battery be matched too. I agree with riba2233 a very small battery (ah ) has to be closely monitored for safety. People without bms run Big batteries for safety ( ah ).

 

[jose]

Recent replies introduced the possibility of BMS solving my dilemma. I am now very interested in that possibility. BMS generated additional questions asked about my specific application:
Battery as stated is 10s3p 18650 cells, what I didn't say was cells are Samsung 29E, pack = 8.7Ah.
Motor is 36V-350W mini-geared front hub, Controller is 17A max. w/ 31LVC. PAS and throttle on this new Ebikeling kit, which runs great on MTB w/ 26" wheels.
Riding should be fairly tame by ES standards; "electric-assist" 10mph, primarily ridden by my wife. This is first Ebike in the family.

Previously I liked the philosophy of keeping complexity of balance ckty off the bike (and in the charging station) for better reliability on the road. Riba2233 has me re-thinking that philosophy; and perhaps what I give up in reliability I may gain in rider and battery safety/longevity. About all I know so far is BMS-Battery sells something like I think I'd need; don't think I should need that $200 programmer once I settle on basic parameters, right?

I've searched ES some for a "to BMS, or not to BMS" thread...so if any links or hints would be highly appreciated. Looks like I have a new research project.

Thanks for all the great info so far!

 

[riba2233]

Just use this combination, charger:

https://bmsbattery.com/ebike-charger-ev-charger/24-alloy-shell-120w-lifepo4-li-ion-lead-acid-battery-ebike-charger-ecitypower-charger.html

And either of these two bms:

https://bmsbattery.com/bmspcm/733-10s-16s-50a-lipo-bms-system-battery-management-system-bms-pcm.html#/cells_in_series-10

https://bmsbattery.com/bmspcm/714-10s-13s-20a-lithium-bms-for-bottle-battery-09-bms-pcm.html#/cells_in_series-10

And that's it, just set and forget, plug and charge, etc

 

[jose]

Riba2233,
Thanks for recommendations on BMS-Batterty boards. Really like the size & price of the 10s BMS, which seems like it could work for me.

Studying the 10s data sheet left a few not answered questions:
Q: Does not show connection points for B+ (or P+ and CH+) ? Maybe on other side of board?
Q: Fuction (purpose) of LED and Short Circuit jumper not stated?
Q: Would Overvoltage level of 4.1V be better than the stated 4.25V for longer battery life?
Q: Would Undervoltage level of 3.2V be better than the stated 2.75V?
Q: Alternative board, "Smart BMS" allows customer to specify Over & Under-voltage levels, do you have any guess if this may be a good choice?
https://bmsbattery.com/bmspcm/330-smart-bms-513-cells-in-series-bms-pcm.html

I forgot to say I already have a bulk charger, it is a 2A Tenergy.
I assume I can continue to use my charger with any of these BMS boards.

Sorry for all the questions, answer any or none. I'm having trouble searching on "BMS".
Many thanks!

 

[riba2233]

Riba2233,
Thanks for recommendations on BMS-Batterty boards. Really like the size & price of the 10s BMS, which seems like it could work for me.

Studying the 10s data sheet left a few not answered questions:
Q: Does not show connection points for B+ (or P+ and CH+) ? Maybe on other side of board?
Q: Fuction (purpose) of LED and Short Circuit jumper not stated?
Q: Would Overvoltage level of 4.1V be better than the stated 4.25V for longer battery life?
Q: Would Undervoltage level of 3.2V be better than the stated 2.75V?
Q: Alternative board, "Smart BMS" allows customer to specify Over & Under-voltage levels, do you have any guess if this may be a good choice?
https://bmsbattery.com/bmspcm/330-smart-bms-513-cells-in-series-bms-pcm.html

I forgot to say I already have a bulk charger, it is a 2A Tenergy.
I assume I can continue to use my charger with any of these BMS boards.

Sorry for all the questions, answer any or none. I'm having trouble searching on "BMS".
Many thanks!

1. yeah, probably on other side
2. led is to signalize when bms is turned on, and short circuit is to power it on. you can use this to turn your battery on and off
3. overcharge is just for protection, it balances to 4.2. infortunately there are no bms's that balance at lower voltage, but you shouldn't have any problems with this
4. no, there are few reasons why that's a good number for lvc
5. I wouldn't recommend it, it can be very unreliable

 

[999zip999]

Can we see a pic of your pack ?

 

[jose]

Thanks again riba2233 for the great information.
I am thinking seriously to buy the 10s BMS you suggested.

As requested from 999zip I tried attaching a picture of my pack, but site only allows 512KiB. Pack has 3 rows of stacked cells; stacked 9 cells on 10, on 11. It is shrink-wrapped so all you could see the red wrap, battery connections and balance connectors.

Do you think the BMS can be wrapped with the batt. pack if electrically insulated? Or does it need more airflow?

 

[999zip999]

Do you have a volt meter or multi meter and can check the charger voltage and post.

 

[jose]

zip999,
The no-load charger voltage reads 42.2V right now...I think i have seen batt pack as high as 42.5V after leaving on charger for about 4 hours.
It is sold as a Smart Charger; Tenergy Model F370-020D.
I would have preferred max. batt charge to be 41V, but opening charger shows not clear how to modify. I was thinking a diode in series w/ Batt pack may lower the max. charge voltage; but maybe the suggested BMS will lower the max charge voltage?

 

[999zip999]

Don't worry about 42.2 it's set to trip the bms to do a bleed down of the cells for balance. Plus the cells will settle down after a short time and not stay at 4.2. I would put a set of 5s sense wires to check each cell with a cellog 8. As I need to know. I guess you have the cells in hand ?

 

[jose]

zip999,
Great info on the charge voltage slightly over 42V....has provided peace-of-mind on that score.

Your suggestion for additional connections for a Cellog 8 raises a slight negative viewpoint to on-board BMS. That is you don't "see" the cell voltages, but instead "trust" the BMS is continuously doing it's job in the background. And if you are the type person who tends to manually monitor the cells; then is a BMS worthwhile? I guess that is another reason why some folks here BMS, and others don't.

I currently have a 6s and a 4s JST connectors on the balance leads...guess I could even use a 6-cell checker if they exist. Of course I will have parallel those balance leads to the appropriate connector(s) for the BMS.

Thanks again!

 

[999zip999]

People who don't use bms would have 8p not 3p. Plus another monitoring system and daily checking battery. You would have to care. Commitment. A One person battery. Can't loan to your brother.

 

[jose]

Good advise on my small battery; BMS it is.

 

[jose]

I ordered this BMS:

http://www.aliexpress.com/store/product/10S-36V-lithium-polymer-battery-BMS-42V-li-ion-battery-BMS-PCB-with-15A-constant-discharge/1379203_32239348688.html

I found the seller from a Nobuo link he posted.
I will report on how well it works.