72V 100A 60Ah 4.3kWh 10s24p 200lbs.....

[Jayls5]

I started buying these Turnigy packs a long time ago because it was such a good bang for the buck. I haven't looked at the cost of A123's pouch cells, but I would have to factor in the extra protection I'd need to build for those pouches along with all of the soldering. At this point, I'd need 60 of their cells to match my Turnigy pack, and they have about the same C rating. Realistically, I could pull 1200A from my Turnigy pack at 20C if I truly needed it.... I might go crazy and upgrade if I end up not being not happy with the current power level). That's 118 horsepower.

I didn't seem to have a problem running the resistive balancers for hours when I tried it out. I immediately took note of the heat vent on the back and made sure to leave that exposed to air. They are only there to do minor balance corrections each charge, not to be used sporadically after a big imbalance has developed. I bought a low 800w (0.18C) charger for my main pack, giving the balancers plenty of time to do their job during the 5.5hr charging process. I'm not sure how quickly you're expecting them to work, but it's going to be slow.

 

[biknut]

I've been doing a lot of battery research lately. I'm looking at 18650 manganese cells for a battery build. They look pretty good as a replacement for my LiFePo4. In the same size space that holds 18 ah now, I could fit 35 ah.

 

[Jayls5]

How long do you consider "storage" for?

Woops, forgot to answer that question. I had my 2.23 kWh (30 battery) pack stored for a full year without touching it. I just left it around 79v, under 4v per cell. It barely moved during the time. The only thing I did was check it once a season to see how far it drained, and it wasn't much. In fact, I'm still using that storage charge for all of these test videos you've been seing.

 

[Jayls5]

I've been doing a lot of battery research lately. I'm looking at 18650 manganese cells for a battery build. They look pretty good as a replacement for my LiFePo4. In the same size space that holds 18 ah now, I could fit 35 ah.

Just be aware that the smaller you go, the more complex the balancing situation is going to be. If you're going for cost effectiveness, I highly suggest making individual 3S bricks and use laptop BMS's to keep them in line. It's super cheap. You could rip apart the "double size" laptop replacement batteries for 12 18650 cells with a BMS ready to go on it. That's actually what I'm going to be running the 12v system on my car with.

 

[miked826]

I started buying these Turnigy packs a long time ago because it was such a good bang for the buck. I haven't looked at the cost of A123's pouch cells, but I would have to factor in the extra protection I'd need to build for those pouches along with all of the soldering. At this point, I'd need 60 of their cells to match my Turnigy pack, and they have about the same C rating. Realistically, I could pull 1200A from my Turnigy pack at 20C if I truly needed it.... I might go crazy and upgrade if I end up not being not happy with the current power level). That's 118 horsepower.

I didn't seem to have a problem running the resistive balancers for hours when I tried it out. I immediately took note of the heat vent on the back and made sure to leave that exposed to air. They are only there to do minor balance corrections each charge, not to be used sporadically after a big imbalance has developed. I bought a low 800w (0.18C) charger for my main pack, giving the balancers plenty of time to do their job during the 5.5hr charging process. I'm not sure how quickly you're expecting them to work, but it's going to be slow.

I expect nothing less than the cell balancer/discharger balancing or discharging cells faster than the heat can accumulate on it and eventually shut the balancer down and turn the LCD screen completely black unless it sits on a bag of ice. I have all the time in the world to wait for balancing but obviously the balancer does not. The intense heat is when using the Discharge function.

Not only do the cells being discharged drop using the eBay Balancer but so do the rest of the cells that I'm trying to level off to. All cells drop at equal rates, meaning I never can discharge single cells to match the rest. Yet that's exactly what it claims to do. LMAO

I not only use that passive balancer but I have a totally different one that is a balancer only (no discharge function) I also use. The results are exactly the same with that one as well. It shuts off after a preset time whether it is done or not. They're cheap because they're worthless. LOL

 

[miked826]

I've been doing a lot of battery research lately. I'm looking at 18650 manganese cells for a battery build. They look pretty good as a replacement for my LiFePo4. In the same size space that holds 18 ah now, I could fit 35 ah.

There are very few alternatives though when talking about batteries capable of dumping massive amounts of amps needed to move the weight of a car or motorcycle at high speed quickly though. That's what we're dealing with.

 

[miked826]

I'm charging a 4Ah pack using a 3A charger. Neither passive balancer keeps up with the charger before certain cells are at peak voltage limits. Which forces me to cut the charger off early.

 

[Jayls5]

I expect nothing less than the cell balancer/discharger balancing or discharging cells faster than the heat can accumulate on it and eventually shut the balancer down and turn the LCD screen completely black unless it sits on a bag of ice. I have all the time in the world to wait for balancing but obviously the balancer does not. The intense heat is when using the Discharge function.

Not only do the cells being discharged drop using the eBay Balancer but so do the rest of the cells that I'm trying to level off to. All cells drop at equal rates, meaning I never can discharge single cells to match the rest. Yet that's exactly what it claims to do. LMAO

I not only use that passive balancer but I have a totally different one that is a balancer only (no discharge function) I also use. The results are exactly the same with that one as well. It shuts off after a preset time whether it is done or not. They're cheap because they're worthless. LOL

Hmm, well I don't use the discharge function. I only use "balance". Did you set your voltages on it? That is an option. Also, what size pack are you balancing? Since mine is only balancing 4 cells at once, there would be less total heat than a 5S or 6S that it claims to support.

 

[miked826]

Hmm, well I don't use the discharge function. I only use "balance". Did you set your voltages on it? That is an option. Also, what size pack are you balancing? Since mine is only balancing 4 cells at once, there would be less total heat than a 5S or 6S that it claims to support.

Yep voltages were set. 5 cells used. I'm "balancing" as we I write this and the cells that aren't getting balanced are also losing voltage. Voltage differentials are about .5 volts from high cell to low cell. Caused solely by me trying to balance or discharge using those crap passive balancers that only are good for very minor voltage differentials.

I need a battery charger that can be set to charge a single individual cell is what I really need. My charger does not do that.

 

[Jayls5]

Yep voltages were set. 5 cells used. I'm "balancing" as we I write this and the cells that aren't getting balanced are also losing voltage. Voltage differentials are about .5 volts from high cell to low cell. Caused solely by me trying to balance or discharge using those crap passive balancers that only are good for very minor voltage differentials.

I need a battery charger that can be set to charge a single individual cell is what I really need. My charger does not do that.

0.5v is a lot. I considered 0.05 significant.

I abused a few of these batteries for fun, jump starting cars with them and stuff like that. Those are the only ones that ever got more than 0.3v off per cell in the pack. When it's off that much, the capacity/impedence difference per cell is usually way off. I have a nice 400w Turnigy balance charger, and it couldn't even burn away the difference as fast as the difference in charge rate between cells.

Now, your passive balancer really should be able to selectively drain certain cells until it maches the rest. In balance mode, did you try setting the low voltage limit to the lowest cell? It shows "light bulbs" (resistors) next to the cells that are actively being drained. Is it flashing the lightbulb next to all of the cells, even the lowest one? It really shouldn't do that unless you're still in "discharge" mode. Discharge mode might keep going until it reaches your set low voltage limit for that setting, where balance might only do the cells that are higher than the lowest like you want.

 

[miked826]

0.5v is a lot. I considered 0.05 significant.

I abused a few of these batteries for fun, jump starting cars with them and stuff like that. Those are the only ones that ever got more than 0.3v off per cell in the pack. When it's off that much, the capacity/impedence difference per cell is usually way off. I have a nice 400w Turnigy balance charger, and it couldn't even burn away the difference as fast as the difference in charge rate between cells.

Now, your passive balancer really should be able to selectively drain certain cells until it maches the rest. In balance mode, did you try setting the low voltage limit to the lowest cell? It shows "light bulbs" (resistors) next to the cells that are actively being drained. Is it flashing the lightbulb next to all of the cells, even the lowest one? It really shouldn't do that unless you're still in "discharge" mode. Discharge mode might keep going until it reaches your set low voltage limit for that setting, where balance might only do the cells that are higher than the lowest like you want.

It's monkey simple to operate and what started out as .02v diff. is now .5v. All my cells are dropping at an equal rate using 2 different balancers regardless of what mode it's in or what lightbulbs are blinking. LOL

 

[miked826]

I have a total of 3 balancers and all 3 are easily overwhelmed if the voltage differential goes beyond about .05v. The odds that all 3 balancers are somehow faulty is practically zero.

 

[Jayls5]

I know, we're just troubleshooting because we are clearly getting different results from the same product. Did you compare voltage readouts with a multimeter? What is your exact voltage limit setting for balance mode? What are your current voltages for each cell?

 

[miked826]

I know, we're just troubleshooting because we are clearly getting different results from the same product. Did you compare voltage readouts with a multimeter? What is your exact voltage limit setting for balance mode? What are your current voltages for each cell?

I've tried various voltage limits for balance mode and nothing mattered. I compared voltages between the 2 different types of balancers and they were all pretty close. Cell voltage differentials now range from 3.3v to 4.1v. The voltage gap has been steadily widening since day 1. LOL

Balancing basically ceases to exist past about .05v differential.

 

[Jayls5]

I've tried various voltage limits for balance mode and nothing mattered. I compared voltages between the 2 different types of balancers and they were all pretty close. Cell voltage differentials now range from 3.3v to 4.1v. The voltage gap has been steadily widening since day 1. LOL

Balancing basically ceases to exist past about .05v differential.

Yeah, I don't mean to imply that you're doing things wrong. I'm just covering all potential problems. I'll try my balancer on one of my abused batteries with wide voltage differences and report back in the morning.

 

[miked826]

Yeah, I don't mean to imply that you're doing things wrong. I'm just covering all potential problems. I'll try my balancer on one of my abused batteries with wide voltage differences and report back in the morning.

No implications taken. I'm just glad that I have somebody to talk to about it. If I only had 1 balancer I would simply chalk it up to a bum balancer but I have 3 of them of 2 different makes and the result is the same with all of them. I just need an active balancer or a BMS, cause passive just ain't cuttin' it.

My charger is just a basic 84v LiPo charger that has no balancing or discharging ability. It is assuming that I have taken care of the cell balancing myself which I now know that I haven't even come close to doing. LOL

 

[Jayls5]

Yeah, as soon as you said it does it on all 3 of your balancers, I knew I have to try it on mine to confirm.

I also have a 84v plain old series LIPO charger, 800w. I'll update in the morning if my balancer fixes my abused 4S battery or does what's happening to you.

 

[biknut]

There are very few alternatives though when talking about batteries capable of dumping massive amounts of amps needed to move the weight of a car or motorcycle at high speed quickly though. That's what we're dealing with.

I've been talking to a guy on es that's running this is pack in his Bomber. His Bike is jacked up to 10 kw. He's running 20s 14p 84v 35 ah. I want this.

This is half the pack. It's made of LG 18650 2500 mah

 

[miked826]

I've been talking to a guy on es that's running this is pack in his Bomber. His Bike is jacked up to 10 kw. He's running 20s 14p 84v 35 ah. I want this.

This is half the pack. It's made of LG 18650 2500 mah

That looks great Biknut and I'll use anything that has a high discharge rate but look at the "Maximum Constant Discharge Rating" of that LG battery at the link below. Ask him what his "Maximum Constant Discharge Rating" is for his entire battery pack......because nothing else really matters.

http://www.vividsmoke.com/lg-18650-he2-35a-2500mah-battery.html

 

[Jayls5]

No need to ask, it's 280A continuous rated multiplied by 74v nominal to make 20.7 kW discharge capable. HOWEVER, I would be hesitant to do that with the cells packed so tightly together with no method of heat removal.