Balancing should be active through the charge cycle. Active balance through discharge can be done with isolated charge pumps on each cell activated by bulk current differential.
running a pouch cell on your eboard .now were talking....great videos love the samba ...I.have a 1.2kw pack on my skateboard .42 mi so far on a charge .snowing hear In new jersey so playing in the shop today.....building a new tube amp ..have a great day
@@jehugarcia Thanks for the reply Jehu. I'm just trying to get this 86' Toyota Van rolling and a BMS is a good bit of battery bone for my little budget. With more batteries, I'll add a BMS. Got a good EV battery source? I'm torn between calb and Tesla modules on a ac 75 or hyper11... Yeesh
+MrBrymstond depends, its normal to be off at the top when bottom balancing, but if they are way off it means your cells or cell groups are are not properly matched so you have change them or add cells to the smallest cell groups
COOL , I am making my second DIY E- Skate , making my Battery Pack with(50) Samsung 30Q cells for a 10S5P . My current pack is made with 40 salvaged Tesla (panasonic) cells
Neither video you linked answers the question of what we are supposed to measure and when. There is no procedure given. It seems to have something to do with matching the state of charge in separate parts of a single massive parallel array. Do you mean to say that you strap all the batteries in parallel then once they are all discharged to the same voltage, then you can put them in series? Isn't the need to top balance eliminated if you have a BMS?
how come there is no voltage cutoff to protect the batteries from getting so low? performance of car will be noticeable once volt gauge shows 10 percent life left in the battery before recharge is needed... the controller should automatically have a volt cutoff to keep the batteries from getting hot when the voltage drops below the standard operating level capacity of the battery..
They just lucked out. The car was equipped with an SOC guage, but they didn't bother looking at it. Another couple miles down the road, one of those cells would have gone POOF...gone forever.
then that means that your controller for your motor has a built in volt cut-off. because if the lights work and everything else works that operates on 12 volts through the converter, that means that the controller is shutting off power to the motor so the batteries do not cook, or fry.... overheat failure due to low capacity... that's why on my Chinese scooter Tao Tao has 12 volt converter for lights volt gauge, horn, alarm, emergency lights usb ports accessories all work when the controller cuts off the battery to the motor. If your batteries are hot to the touch smell bad, then there is probably no safety volt cutoff.. So my 72 volt scooter starts out at 84 volts fully charged when the scooter reaches about 30 miles the batteries drop to about 52 volts the controller cuts off power to the motor so the batteries do not over heat or over cook, or fry or go bad.. also all my 18650 cells have a volt cutoff so when the whole back drops to a certain level the battery will disconnect, protecting the whole battery from overheating... i already had a tao tao go up in flames from a bad controller that was not cutting off battery source to the motor when the sla batteries reached a low critical level, i smelled the acid from the batteries and heard the acid boiling in cases.. then the plastic on the bike got hot and the whole scooter went up in flames... any big electrical vehicle should have this safety feature automatically installed to protect from overheating, and vehicle fires... this is a serious thing this should not be overlooked...
not really the controller only stops because at around 70V my cells are down to around 2.3v each and they can no longer push any amperage. At that point there is no energy left in them to do anything including getting hot. Thats why bottom balancing works they all run out of energy at the same time so no cells can go into reversal
I like this video. Explains something important. But I have a question. At what voltage does EVWest bottom balance the batteries? And then also: To what voltage do they charge them?
Can you build a 48V battery pack out of 4 12v batteries. Then have output voltage as one 48V battery, and still charge it like it is a 12v battery pack with the cells in parallel? (Like have a 12v solar regulator charge a 48V battery, and keep it balanced)
We're doing sort of the same thing. We're converting a food truck from a junky old generator into a battery powered taco truck using the new Bosch lithium batteries. The battery modules are the same ones used in the Mercedes & Fiat cars - 24vdc 68ah modules - and we'll be tying four together for a 48vdc 136ah pack. Coupled with a Magnum inverter, we should be able to run the food truck up to 7 hours before needing a recharge.
Does a 48V electric car go father than a higher voltage car. I read in Home Power, about 20 years ago, some lady would always get a 48V car since she thought they got better range. I guess this can only happen if more efficient.
You can charge this with a 24V generator, and use it as 48V at the same time? What device are you using to control the batteries? Or is it just alot of diodes.
Hi Jehu, great stuff you are posting and thanks for showing the work EV West is doing. A question: is my understanding correct that the only way to make sure the voltages of all the cells are the same on top and bottom is to either make sure they are all the same in capacity or being able to charge individual cells in a pack?
Are you looking into purchasing the Chevy Bolt? We live in Michigan near where they're built, and can't have one yet! Chevy! I can hardly wait, wondering what you think if you test drove it yet........
I'm totally confused Bottom balance is only half of the story (a dangerous half) They have to be in balance at the top,,, Wait what? So what to do if they are not equal at the top "of the charge curve"? (is the top of the charge curve 100%?)
Ok Jehu, I am concerned about these cells having hit rock bottom. Whats the collateral damage. If the pack was between 28 and 50 volts that means the cells had to be between .8 volts and 1.5 volts if you had 32 cells. All the science folks tell us that once below 2.5 volts damage is being done to the cell cathode plating blah blah blah. So a month later hows that car doing, great they recovered but are they now compromised in terms of capacity or are they a higher risk for the dreaded meltdown thermal runaway ..... Is there a possibility that some cells are now damaged or have reduced capacity changing the entire balance equation. You always provide lots of great tips and info I appreciate it, that's why I am asking this question, I know you have thought all this thru. I am just new to this and trying to get my head wrapped around it as I am building my second EV and switching over to Lithium on the old one and staring on Lithium for the new one. Perhaps you will need to do a video on this subject. Call it "Collateral Damage" that will get peoples attention.
If you believe it or not, the austrian military still uses the Pinzgauer. Be aware of not putting your thumbs inside of the steering wheel in rough terrain. They are also nicknamed Daumenbrecher (Thumbbreacker). You have been warned ;)
I'm using a bidirectional flywheel balancer. Do I need to bottom balance as well? *wink wink*. Just because you put same voltages on discharge doesn't mean they'll all top out at same time.. and vice versa. If you have a cell that has less capacity than others in pack, you can't do anything about it with balancing (it will always top out first or last, same with discharge), except if you install a complete cutoff per-cell voltage or install bidirectional balancer.
Awesome find! Can't wait to see it spiffed up and energized. Good tip on the balancing. Are you doing the same with the Tesla packs? How important is maintaining your pack voltage when using multiple chemistries?
hello sir. I am a newbie here. Pls show me a video on how you charge a lithium battery pack like 60v without BMS. as shown on your other youtube that you had this battery for over a year with bms and its still working fine and balanced without BMS.thank you sir
Doesn't the bms bottom balance and top balance they battery? I dont think Tesla connects all the batteries they use in parallel top balance then drain then bottom balance then put them together then use a bms they probably just build the battery charge it test the resting voltages place the closest ones together in groups +-.01v apart maybe less then build their batteries packs.
Just a heads up.. I can't find your video but on one of them you mentioned that a plastic bracket was made with a 3-D printer for mounting an a/c. The bracket had a slot for adjustment. Dayco makes a stretch belt they call "ela" . (www.daycoproducts.com/dayco%C2%AE-ela%C2%AE-belt) .. no adjustment necessary. I first ran across it on an application for a 5.3 Chevy a/c belt P/N E040357 (4 rib). I don't know if they make many sizes, but something like that might simplify things on a tight application. Off the top of my head I don't know if they supply info as to how apart a pair of pulleys has to be to give proper tension. A few phone calls to Dayco would clear that up. Surely other companies make that type of belt.
I disagree with driving your cells before you bottom balance them. Unless you know your cells are well matched I would take care to bottom balance them first.
The thing is that you use new batterys without BMS - so I see your reason to do so. When you top balance cells that are used you will end up having higher range. Long term used cells will have different AmpHours. Yes the lowest one will reach 3 volts first BUT all the other better cells will have higher voltage. So the overall voltage of the battery pack will be higher and >less current drawn< ! So the most used smallest cell will have less stress causing higher range ^.~ Greeting from Germany (by the way I really like EV West and your projects otherwise I wouldn't give you this)
Ha! that Dude said Bottom balanced cells will all die if you run them Dead, funny how my cell don't exactly due what the battery expert says they'll do, that guy is trying to sell you a BMS of course he's going to say bottom balancing does not work.
Well I don't sell anything xD I'm a electric engineering student working with Bosch at the moment A BMS is just extra safety. With Bottom Balancing the pack all cells are more likly to reach 0V at the same time. The real problem with bottom balancing is charging to 100% when your cells have different mAh. For example chargingan 2s to 8,4V can lead to 4,1+4,3 Volts... And reaching 0V is probably instant reducing the mAh extremely so - yeah I think the guy how ran his pack down to 1V will have thrown away a lot the lifespan of his pack.
Man, your videos are awesome, your projects are awesome, and you are awesome. But please try to stop looking at the LCD screen of your camera while recording, or you can follow Casey's method and wear glasses.
I guess it shouldn't matter, but I don't know why it is so annoying to me, it feels like his main concern is make sure the framing is ok, if he looks only at the lens it shows more engagement with the audience, and feels more natural, that's why all vlogers look straight at the lens and not at the camera's LCD screen.
Neither one is "more" important than the other - they are equally important. Bottom balancing creates the 'static' starting point for the charge and top balance is the 'dynamic' part of the equation. Without a bottom balance, one or more of the cells will always create a false charge capacity shutoff.
Chayo Taco but if you don't have well matched batteries and only bottom balance, you could run into a situation where you over volt a cell while charging. This is more dangerous than having one cell limit capacity or go under voltage.
But, I think most people charge to 4V for longevity of the batteries. Thus, you have to balance the pack too. I think the buddy in this video made a mistake you should never do both, only bottom balance and only if you go to 4.00V or lower. I think I am only going to 3.82V.
Do you charge each battery individually then and not use a charger connected across the entire pack? i do not know how else you can charge each battery to 4V. If you are charging each battery to the same voltage, is that not considered top balanced? If you have balanced top after balancing at the bottom is the bottom balance not then canceled out? I don't think it is a thing that you should never do both, but it is more that if you do both, the first one you did is negated by the second.
Also, there are different li-ion technologies. Some only charge to 3.7 some charge to 4.2. By undercharging the battery, you may get a few more charge cycles, but you are also losing use time as you have not charged the battery to its full capacity.
Jehu, you talk about bottom balance, and how important it is...but I still don't know how it's done...charge a EV, plug it in an outlet.
So is the Pinz getting converted?
Who's doing the video series on the pinz?
Balancing should be active through the charge cycle. Active balance through discharge can be done with isolated charge pumps on each cell activated by bulk current differential.
running a pouch cell on your eboard .now were talking....great videos love the samba ...I.have a 1.2kw pack on my skateboard .42 mi so far on a charge .snowing hear In new jersey so playing in the shop today.....building a new tube amp ..have a great day
I have a 32650 12V pack. What is the safest voltage to stop when discharging... and can i set that minimum voltage to a "Low Voltage Buzzer Alarm"?
where did learn bottom balancing?
Electric Pinzgauer conversion? :)
Please share more detail! (Motor and battery sizes, range or hours of operation, anything.)
Thanks!
3:13 what a nice tune. Does anyone know it?
so if you bottom ballance LiPO4 cells, you can run without a bms?
Pretty much, I did it for years…. Oh what am I talking about I’m still running without bms
@@jehugarcia Thanks for the reply Jehu. I'm just trying to get this 86' Toyota Van rolling and a BMS is a good bit of battery bone for my little budget. With more batteries, I'll add a BMS. Got a good EV battery source? I'm torn between calb and Tesla modules on a ac 75 or hyper11... Yeesh
So what do you do if there not in balance at the top? How do you get this done?
+MrBrymstond depends, its normal to be off at the top when bottom balancing, but if they are way off it means your cells or cell groups are are not properly matched so you have change them or add cells to the smallest cell groups
jehugarcia Ok he made it sound as if they hade to be dead on and I never seen two identical batteries. Thanks
Whats up with the Electric Longboard ??
working on it
COOL , I am making my second DIY E- Skate , making my Battery Pack with(50) Samsung 30Q cells for a 10S5P .
My current pack is made with 40 salvaged Tesla (panasonic) cells
What Batterys are you using for the eboard?
Y u dont use gare box in ev ?
How do you bottom balance AND top balance?
You can't, Jehu's "Expert" was wrong.
How is bottom balancing done?
ua-cam.com/video/0KSFitqvap0/v-deo.html
ua-cam.com/video/Vu7Lx9qZCig/v-deo.html
thanks
Neither video you linked answers the question of what we are supposed to measure and when. There is no procedure given. It seems to have something to do with matching the state of charge in separate parts of a single massive parallel array. Do you mean to say that you strap all the batteries in parallel then once they are all discharged to the same voltage, then you can put them in series? Isn't the need to top balance eliminated if you have a BMS?
how come there is no voltage cutoff to protect the batteries from getting so low? performance of car will be noticeable once volt gauge shows 10 percent life left in the battery before recharge is needed... the controller should automatically have a volt cutoff to keep the batteries from getting hot when the voltage drops below the standard operating level capacity of the battery..
They just lucked out. The car was equipped with an SOC guage, but they didn't bother looking at it. Another couple miles down the road, one of those cells would have gone POOF...gone forever.
then that means that your controller for your motor has a built in volt cut-off. because if the lights work and everything else works that operates on 12 volts through the converter, that means that the controller is shutting off power to the motor so the batteries do not cook, or fry.... overheat failure due to low capacity... that's why on my Chinese scooter Tao Tao has 12 volt converter for lights volt gauge, horn, alarm, emergency lights usb ports accessories all work when the controller cuts off the battery to the motor. If your batteries are hot to the touch smell bad, then there is probably no safety volt cutoff.. So my 72 volt scooter starts out at 84 volts fully charged when the scooter reaches about 30 miles the batteries drop to about 52 volts the controller cuts off power to the motor so the batteries do not over heat or over cook, or fry or go bad.. also all my 18650 cells have a volt cutoff so when the whole back drops to a certain level the battery will disconnect, protecting the whole battery from overheating... i already had a tao tao go up in flames from a bad controller that was not cutting off battery source to the motor when the sla batteries reached a low critical level, i smelled the acid from the batteries and heard the acid boiling in cases.. then the plastic on the bike got hot and the whole scooter went up in flames... any big electrical vehicle should have this safety feature automatically installed to protect from overheating, and vehicle fires... this is a serious thing this should not be overlooked...
not really the controller only stops because at around 70V my cells are down to around 2.3v each and they can no longer push any amperage. At that point there is no energy left in them to do anything including getting hot. Thats why bottom balancing works they all run out of energy at the same time so no cells can go into reversal
elitheitguy 12v systems work off an entirely different battery, its isolated from the traction pack.
How nice is that a Pinzi (Pinzgauer) EV conversion
how the heck did the customer run the pack down so far? forgetfulness? or is that thing a business car with multiple drivers?
what is the music?
good stuff! love VW coverage :)
I like this video. Explains something important. But I have a question. At what voltage does EVWest bottom balance the batteries? And then also: To what voltage do they charge them?
Can you build a 48V battery pack out of 4 12v batteries. Then have output voltage as one 48V battery, and still charge it like it is a 12v battery pack with the cells in parallel? (Like have a 12v solar regulator charge a 48V battery, and keep it balanced)
We're doing sort of the same thing. We're converting a food truck from a junky old generator into a battery powered taco truck using the new Bosch lithium batteries. The battery modules are the same ones used in the Mercedes & Fiat cars - 24vdc 68ah modules - and we'll be tying four together for a 48vdc 136ah pack.
Coupled with a Magnum inverter, we should be able to run the food truck up to 7 hours before needing a recharge.
Does a 48V electric car go father than a higher voltage car. I read in Home Power, about 20 years ago, some lady would always get a 48V car since she thought they got better range. I guess this can only happen if more efficient.
You can charge this with a 24V generator, and use it as 48V at the same
time? What device are you using to control the batteries? Or is it just
alot of diodes.
Hi Jehu, great stuff you are posting and thanks for showing the work EV West is doing. A question: is my understanding correct that the only way to make sure the voltages of all the cells are the same on top and bottom is to either make sure they are all the same in capacity or being able to charge individual cells in a pack?
Are you looking into purchasing the Chevy Bolt? We live in Michigan near where they're built, and can't have one yet! Chevy! I can hardly wait, wondering what you think if you test drove it yet........
Marvin Johnson Haven't driven it yet...
Nice E-board!! Would love to see a video with some details!
I'm totally confused
Bottom balance is only half of the story (a dangerous half)
They have to be in balance at the top,,, Wait what? So what to do if they are not equal at the top "of the charge curve"? (is the top of the charge curve 100%?)
Ok Jehu, I am concerned about these cells having hit rock bottom. Whats the collateral damage. If the pack was between 28 and 50 volts that means the cells had to be between .8 volts and 1.5 volts if you had 32 cells. All the science folks tell us that once below 2.5 volts damage is being done to the cell cathode plating blah blah blah. So a month later hows that car doing, great they recovered but are they now compromised in terms of capacity or are they a higher risk for the dreaded meltdown thermal runaway ..... Is there a possibility that some cells are now damaged or have reduced capacity changing the entire balance equation. You always provide lots of great tips and info I appreciate it, that's why I am asking this question, I know you have thought all this thru. I am just new to this and trying to get my head wrapped around it as I am building my second EV and switching over to Lithium on the old one and staring on Lithium for the new one. Perhaps you will need to do a video on this subject. Call it "Collateral Damage" that will get peoples attention.
I made a video answer
If you believe it or not, the austrian military still uses the Pinzgauer. Be aware of not putting your thumbs inside of the steering wheel in rough terrain. They are also nicknamed Daumenbrecher (Thumbbreacker).
You have been warned ;)
I still don't know why you don't like BMS systems. At the very least it would have shut down the battery pack before there was an issue (or would it?)
You should do a video on solar charging your diy powerwall! That would be awesome!
I'm using a bidirectional flywheel balancer. Do I need to bottom balance as well? *wink wink*. Just because you put same voltages on discharge doesn't mean they'll all top out at same time.. and vice versa. If you have a cell that has less capacity than others in pack, you can't do anything about it with balancing (it will always top out first or last, same with discharge), except if you install a complete cutoff per-cell voltage or install bidirectional balancer.
I'm building an electric go kart, any advice?
Just do it.
Awesome find! Can't wait to see it spiffed up and energized.
Good tip on the balancing. Are you doing the same with the Tesla packs? How important is maintaining your pack voltage when using multiple chemistries?
hello sir. I am a newbie here. Pls show me a video on how you charge a lithium battery pack like 60v without BMS. as shown on your other youtube that you had this battery for over a year with bms and its still working fine and balanced without BMS.thank you sir
Doesn't the bms bottom balance and top balance they battery? I dont think Tesla connects all the batteries they use in parallel top balance then drain then bottom balance then put them together then use a bms they probably just build the battery charge it test the resting voltages place the closest ones together in groups +-.01v apart maybe less then build their batteries packs.
Never mind I don't see a bms leads 0.0
Any other filmmakers??
I'm one:)
Just a heads up.. I can't find your video but on one of them you mentioned that a plastic bracket was made with a 3-D printer for mounting an a/c. The bracket had a slot for adjustment. Dayco makes a stretch belt they call "ela" . (www.daycoproducts.com/dayco%C2%AE-ela%C2%AE-belt) .. no adjustment necessary. I first ran across it on an application for a 5.3 Chevy a/c belt P/N E040357 (4 rib). I don't know if they make many sizes, but something like that might simplify things on a tight application. Off the top of my head I don't know if they supply info as to how apart a pair of pulleys has to be to give proper tension. A few phone calls to Dayco would clear that up. Surely other companies make that type of belt.
Parts for Pinzgauer i can find...
you guys should get in contact with some serious Electric RC racers. we have been doing this for years with nickel metal batteries and looks.
EVwest are "serious Electric Racers" i think they hold the electric street legal pikes peak record
Pinzgauer looks like a Humvee predecessor.
Thank you 🙏 ✔️
I´ve acess to drive a Pinzgauer at home... they are soo awesome vehicles. i woner how a electric version would handle :o
What's up with Bendy? An update would be appreciated...
he was checking parallel not flatness. that shows flat to each other.
god I've dreamed of doing an electric pinzgauer. should be an easy conversion with the engine being removed from the transmission.
I disagree with driving your cells before you bottom balance them. Unless you know your cells are well matched I would take care to bottom balance them first.
Still prefer "top balancing" with observation electronics like BMS to extend the range
How do you extend the range? The smallest cell in your series string still dictates when your battery pack is done.
The thing is that you use new batterys without BMS - so I see your reason to do so.
When you top balance cells that are used you will end up having higher range. Long term used cells will have different AmpHours.
Yes the lowest one will reach 3 volts first BUT all the other better cells will have higher voltage. So the overall voltage of the battery pack will be higher and >less current drawn< !
So the most used smallest cell will have less stress causing higher range ^.~
Greeting from Germany
(by the way I really like EV West and your projects otherwise I wouldn't give you this)
Ha! that Dude said Bottom balanced cells will all die if you run them Dead, funny how my cell don't exactly due what the battery expert says they'll do, that guy is trying to sell you a BMS of course he's going to say bottom balancing does not work.
Well I don't sell anything xD
I'm a electric engineering student working with Bosch at the moment
A BMS is just extra safety.
With Bottom Balancing the pack all cells are more likly to reach 0V at the same time.
The real problem with bottom balancing is charging to 100% when your cells have different mAh.
For example chargingan 2s to 8,4V can lead to 4,1+4,3 Volts...
And reaching 0V is probably instant reducing the mAh extremely so - yeah
I think the guy how ran his pack down to 1V will have thrown away a lot the lifespan of his pack.
+Defiro2k8 or probably not
Best balance you can do if you have connection to individual cells is to put connect all the cells in parallel mode for 1 day.
these are huge cells (180AH ) you would need longer than 1 day, maybe a couple of weeks if cell are far from each other
DIY Tesla PowerWall Nope- go away
Man, your videos are awesome, your projects are awesome, and you are awesome. But please try to stop looking at the LCD screen of your camera while recording, or you can follow Casey's method and wear glasses.
gevary krunchy Why?
I guess it shouldn't matter, but I don't know why it is so annoying to me, it feels like his main concern is make sure the framing is ok, if he looks only at the lens it shows more engagement with the audience, and feels more natural, that's why all vlogers look straight at the lens and not at the camera's LCD screen.
So that every comment here accuse me of copying casey? No thank you, I get enough hate as it is.
cool
Music ua-cam.com/video/Ly8-luPbhsY/v-deo.html&list=FLneWCWne_O0MuxGsQ3OHJlw
whats up jehuuuuuuuuuu!
Nice toy
Top balancing is more important than bottom balancing.
Neither one is "more" important than the other - they are equally important. Bottom balancing creates the 'static' starting point for the charge and top balance is the 'dynamic' part of the equation.
Without a bottom balance, one or more of the cells will always create a false charge capacity shutoff.
Chayo Taco but if you don't have well matched batteries and only bottom balance, you could run into a situation where you over volt a cell while charging. This is more dangerous than having one cell limit capacity or go under voltage.
But, I think most people charge to 4V for longevity of the batteries. Thus, you have to balance the pack too. I think the buddy in this video made a mistake you should never do both, only bottom balance and only if you go to 4.00V or lower. I think I am only going to 3.82V.
Do you charge each battery individually then and not use a charger connected across the entire pack? i do not know how else you can charge each battery to 4V. If you are charging each battery to the same voltage, is that not considered top balanced? If you have balanced top after balancing at the bottom is the bottom balance not then canceled out? I don't think it is a thing that you should never do both, but it is more that if you do both, the first one you did is negated by the second.
Also, there are different li-ion technologies. Some only charge to 3.7 some charge to 4.2. By undercharging the battery, you may get a few more charge cycles, but you are also losing use time as you have not charged the battery to its full capacity.
first u need Buddha balance. lol
Yeah try to power a toaster with bike power: ua-cam.com/video/S4O5voOCqAQ/v-deo.html
As educational videos goes this video is pretty much useless useless. The title has nothing to do with what's on the video.
how the heck did the customer run the pack down so far? forgetfulness? or is that thing a business car with multiple drivers?
not sure