LiPo batteries and BMS

[JimmyB]

My early R/C battery conversions were using Lithium Polymer (LiPo) battery packs, it would seem these do not come with Battery Management Systems (BMS) to keep the weight down for model aircraft use, and so are balanced charged via the multi-pin plug (number of cells plus negative). My question to the wise and knowledgable is: using the multi-pin socket as the cell outputs can I add a BMS to the battery, and then use the standard 2 pin jack plug to charge these.
Many thanks in advance for your responses.

 

[PhilP]

With BMS boards, then yes.

But....
It will depend a little on the charger you are using. - Some charge through the 2-pin, but must have the multiway connected, else they will not charge.

Your charger must be suitable for Li-Po charging. You should NEVER use a charger designed for other types of batteries.
(For completeness of information).

PhilP

 

[JimmyB]

With BMS boards, then yes.

But....
It will depend a little on the charger you are using. - Some charge through the 2-pin, but must have the multiway connected, else they will not charge.

Your charger must be suitable for Li-Po charging. You should NEVER use a charger designed for other types of batteries.
(For completeness of information).

PhilP

Phil, many thanks, my "smart" charger will charge most battery types, and only needs the multi-pin connector for balance charging, not normal charging, and I would assume with our low usage the BMS would manage most of this.

 

[GAP]

This how I "rolled" my own

Making 18650 Lithium Ion Battery Packs

After the failure of my third model store bought LiPo battery in my Bachmann Shay and Consolidation ("Connie")I decide that I would make my ...

ringbalin-light-railway.blogspot.com

If I understand correctly you want to add a BMS to LiPo's that do not have one; then cutting off the leads to the individual cells and the output and connecting the BMS board as if you are making a pack up should work.
Following the schematic should help do this.
Just be careful to measure everything twice before connecting, it may be an idea to discharge the cells down before starting.

 

[justme igor]

If putting your cells in a "x"p configuration, then make sure that all the "x"s connected cells are at the same mah!
It does not matter if the cells in the "x"p configuration are (for example!) 800mah and 1200mah, but they will give 2000mah.
Make sure the rest of the "x"p "packs" are also in the 2000mah range.

I presume that you are using new cells?
If a cell get older it will give not so much as when they were new.
If your cells were new and give 2000mah and now they give (remaining mah) a 1000mah, it is time to buy new.(50%soh)

in certain cases you can do without a bms, but you will need a balancing bord in case of a 2s or more.
This has to do with the certain charge and discharge speed of the cell itself.
In any case you would need a charging board that match with the chemistry of the cell
You already have a balancer-charger. why change?

I can set a 100 stages for you, but i would like then to have some more info:
operating V
number of P arralel and the number of S eries.
For now i would say a cheap charging and or balancing board will do what you need, match your cells and match your balancing or charging board accordingly to your "x"s

with best regards Igor