Cheaper alternative to bms that would make charging easier?

[Njakts]

Hi!

I was thinking about board charing methods and had an idea that might work.
Lets say, you have a board with 6s battery and you want to charge it with single plug and in the same time be sure that all cells have same charging conditions.

Then why not put a charger on each cell individually? I am talking about TP4056 charger circuits available super cheap on ebay.
10pcs for 6$
http://www.ebay.com/itm/10pcs-TP4056-5V-1A-Lithium-Battery-Charging-Board-Charger-Module-for-Arduino-/370941024039?hash=item565dced727:g:fqsAAOSwPhdVUCrP

these chargers will charge 1s lipo by monitoring current and voltage. once voltage reaches 4.2v, current drops to 0.

I have this charger in my custom remote.
It also has 2 leds- red and blue, one indicating charging and other - when battery is full.

The idea is to connect inputs of these chargers parallel and outputs to each cell individually and that would give you input charging voltage of 5volts and if each cell charges with 1amp = 5v and 6amps for 6s pack. If you have a 5000mAh pack, charging empty-full would take around 5h

Next youll need to make a nice 2 pole connector and get a laptop style power supply that can supply 5v and 6amps. And this would give you charger that you can carry around in your back pack and take out in any bar or cafe without others thinking that you are some kind of a freak pulling out balance charger with bundle of wires.
Chargers should be placed so that it is possible to see leds on them to see when all cells are charged.

Only downside with this I see is that cells are not balanced mid way, They all are charged individually so if you pull the plug mid charging voltages on each cell can differ a little, but if you are always charging your board to full, then i dont see any problems.

What are your thoughts about this?

 

[whereswally606]

a) they are only 1amp
b) you would need to isolate the grounds which can be done with isolated DCDC (1 per cell) which will probably cost more than the circuits you posted.

the bc168 does this style of charging but you need to remember to separate your pack at every 6s as they aren't isolated either but you will get 5amps easy out of them (they are more expensive though) and there are 9 cell variants too now so you could mix and match for different total cell counts. But you must remember to break the pack between the chargers else you will toast the chargers

 

[friendly1uk]

A bms is cheaper and does more. Things like lvc so you don't kill your pack on the first ride, Or cut your ride short in fear that you might.

If there were a viable alternative, at least one manufacturer would do it. Instead, they have taken them 10 chargers and put it on one board with the required safety additions and charge level indication, selling it for $20

There really is no alternative. That's why they sell in volumes so great the price is so low.