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

[miked826]

I can't charge the screwed up bank without cutting off the charger early on the good bank so now I'm trying to discharge the good bank down to the same level as the bad so I can charge both banks up together. I can't isolate the packs cause I don't have a 37V charger either.

What a PITA. This will drive you insane quickly. LOL

 

[Jayls5]

I can't charge the screwed up bank without cutting off the charger early on the good bank so now I'm trying to discharge the good bank down to the same level as the bad so I can charge both banks up together. I can't isolate the packs cause I don't have a 37V charger either.

What a PITA. This will drive you insane quickly. LOL

I'm going to charge that newly balanced pack on my charger that was previously unable to get it to balance charge all of the way and tell you if it did the trick. It might still go unbalanced during the charge, so don't go out of your way and get one just yet.

Anyways, you can take any old lithium battery charger (for 14500, 18650, etc), and just use some alligator clips and individually charge a cell through the balance leads of your LIPO battery. Just check which cell you need charged with a multimeter, then connect some single stranded wire right into the balance plug. That's how I charge my 2S laser pistol actually, one cell at a time through the balance leads.

 

[biknut]

I'm going to charge that newly balanced pack on my charger that was previously unable to get it to balance charge all of the way and tell you if it did the trick. It might still go unbalanced during the charge, so don't go out of your way and get one just yet.

Anyways, you can take any old lithium battery charger (for 14500, 18650, etc), and just use some alligator clips and individually charge a cell through the balance leads of your LIPO battery. Just check which cell you need charged with a multimeter, then connect some single stranded wire right into the balance plug. That's how I charge my 2S laser pistol actually, one cell at a time through the balance leads.

This is going to show my ignorance, but does a BMS normally charge your battery through the balance leads?

This is the problem with buying a bike complete from a factory, I don't know how it works. I just plug the charger into the XLR port, and somehow the right amount of electrons magically get into the battery cells lol.

 

[miked826]

I'm going to charge that newly balanced pack on my charger that was previously unable to get it to balance charge all of the way and tell you if it did the trick. It might still go unbalanced during the charge, so don't go out of your way and get one just yet.

Anyways, you can take any old lithium battery charger (for 14500, 18650, etc), and just use some alligator clips and individually charge a cell through the balance leads of your LIPO battery. Just check which cell you need charged with a multimeter, then connect some single stranded wire right into the balance plug. That's how I charge my 2S laser pistol actually, one cell at a time through the balance leads.

The only charger I got is 84V or nothing. There is no in between voltage.

 

[Jayls5]

The only charger I got is 84V or nothing. There is no in between voltage.

Well, I ran that messed up cell through my balance charger after my passive balancer tried to fix it. It seemed to have worked. 4.17-4.2v on average at end of charge

 

[Jayls5]

This is going to show my ignorance, but does a BMS normally charge your battery through the balance leads?

This is the problem with buying a bike complete from a factory, I don't know how it works. I just plug the charger into the XLR port, and somehow the right amount of electrons magically get into the battery cells lol.

I missed this question. Honestly, I don't know. I'd have to look at the circuit. I've seen them manage all input/output current as well as only charge current. The most common and cheap method is resistive balancing. There are also designs that redirect excessive charge to lower charged cells.

In regards to BMS's that directly manage all input/output current... I personally think that's a bad design, since the controller is already responsible for output current. It's unnecessary redundancy which increases inefficiency. Yours has an XLR port. That doesn't really say what's going on inside. What type of battery was it in the first place? SLA?

 

[Goat Herder]

Well I read a lot of these post. Thanks for a great informative thread Guys. Some of the threads started by the OP here have taught me more than I knew for sho.

Question once the cells get balanced they typically stay that way? Or is this luck?

I have a full sus jewel of a bike at the ready when I get some of this stuff sorted. Money always the major factor. I wanna build a 50 plus mph model. Not far off from Bikenuts.. With many of your folks improvements. Stability mad power and distance. Picky I know lol. Basically a sweet smooth hotrod.

You folks know the stuff..

Bikenut you about ruined me with that Russian's hopped up bike. That'un is perfect I will take that one! Jee Whiz now I gotta stop thinking about it.

 

[miked826]

Well, I ran that messed up cell through my balance charger after my passive balancer tried to fix it. It seemed to have worked. 4.17-4.2v on average at end of charge

Yeah I don't know what I was thinking when I thought I could just get by with the passive balancers. It wish simply wishful thinking is all. LOL

 

[miked826]

Well I read a lot of these post. Thanks for a great informative thread Guys. Some of the threads started by the OP here have taught me more than I knew for sho.

Question once the cells get balanced they typically stay that way? Or is this luck?

I have a full sus jewel of a bike at the ready when I get some of this stuff sorted. Money always the major factor. I wanna build a 50 plus mph model. Not far off from Bikenuts.. With many of your folks improvements. Stability mad power and distance. Picky I know lol. Basically a sweet smooth hotrod.

You folks know the stuff..

Bikenut you about ruined me with that Russian's hopped up bike. That'un is perfect I will take that one! Jee Whiz now I gotta stop thinking about it.

I can say from what I've experienced that each individual cell seems to have it's own mind as far charging and discharging goes. Some of the cells march to the same beat, and others don't, for whatever reason. They all have to be forced to march lock step to the same beat......actively and electronically. Not with simple plug and play balancers........especially when charging those cells.

 

[Jayls5]

So, charging up my 2.23 kWh pack as we speak, getting ready to test drive my Electric Sandrail. 800w running in series, resistive balancers micro-correcting along the way:

 

[miked826]

So, charging up my 2.23 kWh pack as we speak, getting ready to test drive my Electric Sandrail. 800w running in series, resistive balancers micro-correcting along the way:

I never made it this far on my battery testing. I only had bought 2 balancers and then 1 more later on and I actually needed 4 of them. LOL

 

[Jayls5]

I got the thing running! I did not expect it to launch like this!

https://www.youtube.com/watch?v=icPn7w4Tw_8

 

[miked826]

3 days straight of balancing later and I've got the high pack down .3v and falling. LOL

 

[Jayls5]

I'm not sure if you use 12v electronics in your bike, but here's my ghetto fabulous solution if you do. I had a laptop that someone sold me that my computer didn't recognize, so I tore it apart and compacted it. Then I wired another 5AH 3S LIPO to share the BMS with it, so I have an effective 10AH 11.1v lithium battery to run things now. I'll just be wrapping it up, and it's good to go lol.

 

[miked826]

I'm not sure if you use 12v electronics in your bike, but here's my ghetto fabulous solution if you do. I had a laptop that someone sold me that my computer didn't recognize, so I tore it apart and compacted it. Then I wired another 5AH 3S LIPO to share the BMS with it, so I have an effective 10AH 11.1v lithium battery to run things now. I'll just be wrapping it up, and it's good to go lol.

My bicycle has state of the art LED lighting, front to back, including the head and brake lights and working turn signals. All the lighting uses so little watts, that all I have to use is a 12V sealed lead acid burglar alarm battery and it lasts at least 16 hours straight. That battery DOES NOT lose voltage while just sitting unused. It holds on to it. $8 LOL

 

[Jayls5]

My bicycle has state of the art LED lighting, front to back, including the head and brake lights and working turn signals. All the lighting uses so little watts, that all I have to use is a 12V lead acid burglar alarm battery and it lasts at least 16 hours straight. That battery DOES NOT lose voltage while just sitting unused. It holds on to it. LOL

I'm pretty knowledgeable about LED's. I could probably tell you what model it is just by looking at the die in your headlight. Cree XML's can take up to 10w by themselves and can put out around 1000 lumens. How big is your SLA battery? I just know that bike people love to save weight where they can, and you could probably get away with a 1 pound LIPO battery replacement.

Edit, I see you posted a picture. That thing looks like it weighs a ton, and it has the same power rating as my 1 pound lipo (and even less after factoring in Peukert's law).

 

[miked826]

I'm pretty knowledgeable about LED's. I could probably tell you what model it is just by looking at the die in your headlight. Cree XML's can take up to 10w by themselves and can put out around 1000 lumens. How big is your SLA battery? I just know that bike people love to save weight where they can, and you could probably get away with a 1 pound LIPO battery replacement.

Edit, I see you posted a picture. That thing looks like it weighs a ton, and it has the same power rating as my 1 pound lipo (and even less after factoring in Peukert's law).

Battery is 5Ah 12V. Here it is again. Triple barrel CREE 3x3w with working High and Low beams cause I like to keep it simple. LOL

 

[biknut]

I really like having all my LEDs powered by my main Battery. Power consumption is less than 1/2 amp. When you're already carrying a giant battery, why not utilize it, instead of having an axillary battery to have to charge separately?

 

[Jayls5]

Too far away to identify, but based on your description they are either Cree XRE or XPG.

Weigh out that lead acid battery and consider if you want to remove all of that weight minus 1 pound. Although more expensive, it's really not all that bad to upgrade, and LIPO don't really degrade quickly either.

 

[Jayls5]

I really like having all my LEDs powered by my main Battery. Power consumption is less than 1/2 amp. When you're already carrying a giant battery, why not utilize it, instead of having an axillary battery to have to charge separately?

Because then you have to get a DC/DC converter, which costs more than the LIPO + charger for decent output. I can just plug in a simple 12v A/C adapter up to this battery I made and it auto-balances. I'll have the plug go in parallel with my main charger so it's still just 1 simple wall charger plug. It's all about cost effectiveness in my book

My total cost of my car is under 4 grand.