Poor mans battery balancer

[leon.davibe]

@wingnut771

been looking for an affordable/in stock balancer for a buddies 5s configuration
we first tried the cells he got to see if some work and to build a pack with what works ie top balanced and ran without a bms
some cells good now we are looking for a BMS/balancer

the only items i could see for his setup (5S LTO) locally is the, 4s-8s JKbms from lithium-cells.co.za
it does have a minimum requirement of 6cells (for LTO) hence the problem, i do think there is a solution to make the bms run on his 5s setup but budget is a stumbling block at the moment

looking for a cheap solution had me stumble on to this cheap diy balancer , that can work on any S config as individual cells just get resistance added when reaching full SOC, naturally i will have to amend the design to his 2.3v cells ie get a zener diode around 2.5-2.7v still need to research what will work best , and use the parallel design not series

Electric Vehicle Discussion List - Lee Hart's Minimalist Battery Regulators

www.evdl.org

 

[wingnut771]

@wingnut771

been looking for an affordable/in stock balancer for a buddies 5s configuration
we first tried the cells he got to see if some work and to build a pack with what works ie top balanced and ran without a bms
some cells good now we are looking for a BMS/balancer

the only items i could see for his setup (5S LTO) locally is the, 4s-8s JKbms from lithium-cells.co.za
it does have a minimum requirement of 6cells (for LTO) hence the problem, i do think there is a solution to make the bms run on his 5s setup but budget is a stumbling block at the moment

looking for a cheap solution had me stumble on to this cheap diy balancer , that can work on any S config as individual cells just get resistance added when reaching full SOC, naturally i will have to amend the design to his 2.3v cells ie get a zener diode around 2.5-2.7v still need to research what will work best , and use the parallel design not series

Electric Vehicle Discussion List - Lee Hart's Minimalist Battery Regulators

www.evdl.org

A poor man wouldn’t buy LTO.

 

[leon.davibe]

A poor man wouldn’t buy LTO.

Yea got cells for free so found some good cells

Tested it for his load ie TV/internet/lights via suicide lead and he could almost make it through 3 x 2hr load sheddings before the inverter switched off
5min before the power came on

Sorted him with a old laptop charger with buck to keep well away from top for the moment
And still charges way quicker than the car charger as it will push CC till Voltage selected the car charger (6A he has already) tapers and takes ages to charge full

And since he will recharge after every shedding he is sorted for now

 

[Magnum]

If you cant find one build your own.

 

[wingnut771]

Yea got cells for free so found some good cells

Tested it for his load ie TV/internet/lights via suicide lead and he could almost make it through 3 x 2hr load sheddings before the inverter switched off
5min before the power came on

Sorted him with a old laptop charger with buck to keep well away from top for the moment
And still charges way quicker than the car charger as it will push CC till Voltage selected the car charger (6A he has already) tapers and takes ages to charge full

And since he will recharge after every shedding he is sorted for now

Pics?

 

[leon.davibe]

@wingnut771

Getting full and balancing with bulb in one go
My buck had popped and the new one had not arived yet

Not even a month later and we already detected some drift in cells

5S2P 80ah 11.5v nominal

range 9v - 14v
So his 10v inverter shutdown is perfect to stay away from cells abolute min of 7.5v

 

[wingnut771]

@wingnut771

Getting full and balancing with bulb in one go
My buck had popped and the new one had not arived yet

Not even a month later and we already detected some drift in cells

5S2P 80ah 11.5v nominal

range 9v - 14v
So his 10v inverter shutdown is perfect to stay away from cells abolute min of 7.5v

Pics of inverter and charger?

 

[soulie]

@wingnut771

been looking for an affordable/in stock balancer for a buddies 5s configuration
we first tried the cells he got to see if some work and to build a pack with what works ie top balanced and ran without a bms
some cells good now we are looking for a BMS/balancer

the only items i could see for his setup (5S LTO) locally is the, 4s-8s JKbms from lithium-cells.co.za
it does have a minimum requirement of 6cells (for LTO) hence the problem, i do think there is a solution to make the bms run on his 5s setup but budget is a stumbling block at the moment

looking for a cheap solution had me stumble on to this cheap diy balancer , that can work on any S config as individual cells just get resistance added when reaching full SOC, naturally i will have to amend the design to his 2.3v cells ie get a zener diode around 2.5-2.7v still need to research what will work best , and use the parallel design not series

Electric Vehicle Discussion List - Lee Hart's Minimalist Battery Regulators

www.evdl.org

go have a look on car audio sites ,we used to make balancers for basic systems using 2 and more extra batteries .it was partly 10 watt ceramic resistors in aluminium casings ,

 

[leon.davibe]

Pics of inverter and charger?

Budget like i said

No pics of charger

Put a buck converter in a light switch box with a hole for tiny fan powered from the output side , laptop 65w psu as source

 

[soulie]

Budget like i said

No pics of charger

Put a buck converter in a light switch box with a hole for tiny fan powered from the output side , laptop 65w psu as source

just be very aware those things cook batteries ,yes ive witnessed it ,they boil a gell battery dry .

 

[wingnut771]

just be very aware those things cook batteries ,yes ive witnessed it ,they boil a gell battery dry .

What things? Also, not a dead acid thread.

 

[leon.davibe]

just be very aware those things cook batteries ,yes ive witnessed it ,they boil a gell battery dry .

Yea this one the charger portion is faulty , he was using the car charger

But the problem with some car chargers is the same

They have a normal/rapid switch

And what many don't know how it achieves rapid (no idea of the correct terms to explain)


ie normal uses half the coil ,or half the sine wave rapid uses both sides of
ac transformer essentially doubling the output voltage before rectification

(you don't see it cause it is dragged down to battery voltage) creating bigger potential difference and thus faster charging but if no overvoltage protection it boils the battery too

Moral of the story rapid while flat normal close to float/full

 

[soulie]

What things? Also, not a dead acid thread.

get a life,wasnt talking to you ,if i want your opinion ill go flush a toilet somewhere

 

[wingnut771]

get a life,wasnt talking to you ,if i want your opinion ill go flush a toilet somewhere

and yet my name is all over this thread.

 

[soulie]

and yet my name is all over this thread.

and Mr Da.vibe knows what im talking about ,you have no clue on how these things charging circuits work ,because you comment lots doesnt you a genius make .,neither is this your thread ,just an irritating noise in the background .

 

[wingnut771]

/unsubscribes.