efficient bms with active balancing system using fliback tra

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legerme1955

100 mW
Joined
Oct 19, 2011
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Esquema 3 cells.JPG:x [attachment=1]ti 5430.JPGHi, freinds 3 years ago i started up developping a solar powered e-bike prototype. On that way i learned a lot about batteries, charging and balancing, the worst and darkest side of the process. TIred about passive chineese bms systems i decided to built up using mi limited electronics knowledge an efficient active balancing system based on multiple little dc-dc transformers mounted on flyback system. I have actually choiced two types of them from murata and and usin ti dc dc converters 60v to 3.8. But i have a problem withe shematics originally disigned with transistor´s switches; now directly using small dc converters for each cell. The BIGGEST problem is how to resolve that problem making them working at the same time avoiding the polarity problems. I need help on to resolve that shematics properly mounting the diodes to split the cells and charge/balancing them individualy , all enables and controls using 1 or 2 pics or Ic. Somebody can help me to solve that challenge, please.
 

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legerme1955 said:
:x [attachment=1]ti 5430.JPGHi, freinds 3 years ago i started up developping a solar powered e-bike prototype. On that way i learned a lot about batteries, charging and balancing, the worst and darkest side of the process. TIred about passive chineese bms systems i decided to built up using mi limited electronics knowledge an efficient active balancing system based on multiple little dc-dc transformers mounted on flyback system. I have actually choiced two types of them from murata and and usin ti dc dc converters 60v to 3.8. But i have a problem withe shematics originally disigned with transistor´s switches; now directly using small dc converters for each cell. The BIGGEST problem is how to resolve that problem making them working at the same time avoiding the polarity problems. I need help on to resolve that shematics properly mounting the diodes to split the cells and charge/balancing them individualy , all enables and controls using 1 or 2 pics or Ic. Somebody can help me to solve that challenge, please.
Click to expand...

meh ...
 
HI FRIENDS IS NOT JUST A THEORY, I AM WORKING, ACTUALLY, WITH SMALL DC CONVERTERS FROM MURATA, OR TI DC -TO DC. NOT CAPACITORS, YET, MAY BE LATER I WILL INCORPORATE ULTRACAPS TO THE POWER BANK. I NEED TO CHECK OUT BOTH, THE ONLY PROBLEM I HAVE IS TO RESOLVE THE POLARITY INCOMPABILITY, THE CELLS NEED TO BE CHARGED BY PACKS OF SIMILAR POLARITY AND FOLLOWING TO THE NEXT SIMILAR POLARITY. THE ONLY WAY IS TO USE LARGE DC DC CONVERTERS , 3/5AMPS TO USE ALL THE POWER OF THE BATTERY UNTIL GET CHARGED AGAIN, IS THE ONLY WAY TO GET ALL HIS ENERGIE. THE LINES AND VALUES WILL BE CONTROLLED BY AN IC, PIC OR SIMILAR. MOST MANUFACTURESRS ARE WORKING ON FLYBACK TRANSFORMERS, ALL THE PASSIVE SYSTEMS JUST WASTE ENERGIE ON HEAT, IS NOT COOL; ACTUALLY GERMANS, AUSTRALIANS ARE WORKING ON SIMILAR CONCEPTS BUR THEY USE FEW AMP FOR BALANCING, I PROJECT TO USE NO LESS THAN 3 AMPS, AND ALSO WITH THE THE HELP OF REGENERATIVE FUNCTION IS POSSIBLE THIS CONCEPT IS POSSIBLE. MINE HAVE A BIG SOLAR PANNEL ONTHE ROOF( 320W) WITH SATELLITE SOLAR CELLS. iS NOT A CHAEP PROJECT BUT LOOK AT THE PRICE OF CSIRO AND GERMANS BMS. MANUFACTURERS !!. ATMEL USE SIMILAR CONCEPT, BUT ONLY BALANCE 1 AMP.; LINEAR ALSO BUT THEIR SISTEMS DO NOT WORK WITH LIFEPO4, . THEIR FAST CHARGING CAPACITY MAKES DECIDE TO BUILD UP MI OWN SYSTEM WITH TAHT BAT. CHEMISTERY. IS NOT OUT OF MI POSSIBLITY´S AND NOT MORE EXPENSIVE THAN ANY OF THE REAL EFFICIENT ONES. i AM NOT ENGENEER AND I NEED SOME HELP TO RESOLVE THE PLARITY AND WHERE TO MOUNT THE DIODES, WELL I AM WORKING ON IT....
 
legerme1955 said:
HI FRIENDS IS NOT JUST A THEORY, I AM WORKING, ACTUALLY, WITH SMALL DC CONVERTERS FROM MURATA, OR TI DC -TO DC. NOT CAPACITORS, YET, MAY BE LATER I WILL INCORPORATE ULTRACAPS TO THE POWER BANK. I NEED TO CHECK OUT BOTH, THE ONLY PROBLEM I HAVE IS TO RESOLVE THE POLARITY INCOMPABILITY, THE CELLS NEED TO BE CHARGED BY PACKS OF SIMILAR POLARITY AND FOLLOWING TO THE NEXT SIMILAR POLARITY. THE ONLY WAY IS TO USE LARGE DC DC CONVERTERS , 3/5AMPS TO USE ALL THE POWER OF THE BATTERY UNTIL GET CHARGED AGAIN, IS THE ONLY WAY TO GET ALL HIS ENERGIE. THE LINES AND VALUES WILL BE CONTROLLED BY AN IC, PIC OR SIMILAR. MOST MANUFACTURESRS ARE WORKING ON FLYBACK TRANSFORMERS, ALL THE PASSIVE SYSTEMS JUST WASTE ENERGIE ON HEAT, IS NOT COOL; ACTUALLY GERMANS, AUSTRALIANS ARE WORKING ON SIMILAR CONCEPTS BUR THEY USE FEW AMP FOR BALANCING, I PROJECT TO USE NO LESS THAN 3 AMPS, AND ALSO WITH THE THE HELP OF REGENERATIVE FUNCTION IS POSSIBLE THIS CONCEPT IS POSSIBLE. MINE HAVE A BIG SOLAR PANNEL ONTHE ROOF( 320W) WITH SATELLITE SOLAR CELLS. iS NOT A CHAEP PROJECT BUT LOOK AT THE PRICE OF CSIRO AND GERMANS BMS. MANUFACTURERS !!. ATMEL USE SIMILAR CONCEPT, BUT ONLY BALANCE 1 AMP.; LINEAR ALSO BUT THEIR SISTEMS DO NOT WORK WITH LIFEPO4, . THEIR FAST CHARGING CAPACITY MAKES DECIDE TO BUILD UP MI OWN SYSTEM WITH TAHT BAT. CHEMISTERY. IS NOT OUT OF MI POSSIBLITY´S AND NOT MORE EXPENSIVE THAN ANY OF THE REAL EFFICIENT ONES. i AM NOT ENGENEER AND I NEED SOME HELP TO RESOLVE THE PLARITY AND WHERE TO MOUNT THE DIODES, WELL I AM WORKING ON IT....
Click to expand...

I give up ...
 
[ATTACH type="full" alt="esquema baterias [attachment=0]Esquema Generico juanma.hi i dont want o use transistors or mosfets hard to drive i just want to use diodes for polarity isolation , is ti possible check me las t shematics, thanks
[attachment=1]Esquema Generico juanma.pdf"]0[/ATTACH]
 

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to nubuo, paasive cell balancing use resistors to drop the extra charge from higher cells dissipate by heat with the resistors, many energy is lost on that process, flyback converters use the proper power from the batteri to power the lower cells . Nothing in power control means 100% of efficiency or 0 losses, thE mportant is to get suitable and ruggedised devices with the maximum efficiency.
 
I DONT KNOW ABOUT ELECTRONICS OR CIRCUITS , I JUST LOOK FOR HELP TO RESOLVE THE ISOLATIONS PROBLEMS IN MI CIRCUIT, WITHOUT USING TRANSISTORS OR MOSFETS, I WANT TO USE INDIVIDUAL DC DC CONVERTERS TO POWER UP EACH CELL FOR AN ACTIVE CELL BALANCING SYSTEM!!!!
 
start by learning some electronics and then take a course in circuits so you can figure out how to implement your ideas.

your idea is already part of the generally considered methods for actively balancing a battery pack.

but the designs are nothing like what you are guessing at.

i have done something similar when i had a set of six 12V 100Ah Deka gel SLA packs that had one pack with much less capacity than the others. i used an iCharger to distribute charge from the two 12V packs with the highest capacity to the one 12V pack with the lowest capacity during the discharge.

i was able to add about 15% of the low pack's capacity to it during the discharge so that the entire battery would now produce 58Ah instead of the 40Ah it had been limited to when i first began reconditioning the SLA packs.
 
FOR SHURE IS NOT NEW, LINEAR USE ic´s TO BALANCE ACTIVELY THE CELLS BUT NOT WORK FOR LIFEPO4 , ATMEL JUST BALANCE 1 AMP, AND MI PROBLEM IS I HAVE 16 CELLS , 6P 16S , I JUST LOOK FOR HELP NO NEED NEGATIVE ADVISINGS I AM NOT FOOL, BUT NOBODY KNOWS ABOUT ANALOGIC ELECTRONICS. I BELEVE IS EASY TO RESOLVE AND IT CAN WORK USIN THE PROPER ISOLATION OR BALANCING BY PACKS OF 4/6 or 6 cells,
 
Popcorn-02-Stephen-Colbert.gif
 
Whats wrong about to use caps? is better for reading dont? i slog hard evry day i use to work up mi projects , is not the first one, thanks i dont have time for learning electronics right now , i try to work out an efficient and cheap active balancing system. there are not much cheap in the market.
 
legerme1955 said:
Whats wrong about to use caps? is better for reading dont?
Click to expand...
Caps is not better for reading. It makes peoples' eyes hurt.
there are not much cheap in the market.
Click to expand...
There is probably a reason for that, and the reason is probably because this is a difficult project and expensive components. If it was easy and cheap, someone else would've already made it.
 
:oops: :oops: :shock: i have perform actually mi design using isolated dc converters and i will start in contruction
NB i am not engeneer i am intuitive and mi target is to built up a simple and efficient cell balnacing system, thanks for your help and understanding. i Know that big developpers use bidirectional dc converters but tey are ,actually far from mi budget

 
for people who uses EV every day whe know the importance of an an efficient active balancing systems while load, the bat stops because a cells turn to low soc and you check your battery and you see you could run one hour more. I used many chineese passive balancing but they work only in regenerative function , they are many really efficient active balancing bms from 500€ for 16 cells Fraunhoffer from DE. csciro austrl have really efficient active balancinf systems for 24 cells from 750 aus dol. more and more they will become cheapper and cheapper on demand , is the futur not inefficient passive/bleeding balancers. the cost of mi project with programing will be around 1200 €,after some test i will produce 20/30 and sell them for me is an affordable investement thanks for your support.....
 

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