My excellent adventure through some battery builds
- Thread starter ElectricGod
- Start date
ElectricGod
10 MW
I've been using smart BMS's on everything for a good while now. I won't be going back to dumb BMS!
China still has quality issues, but they have figured out how to make inexpensive smart BMS's that work.
China still has quality issues, but they have figured out how to make inexpensive smart BMS's that work.
ElectricGod
10 MW
As many people know by now, I like to post lots of pictures and explain things as I go. This helps people reading my threads duplicate what I did. I've built quite a few packs now, but never documented all the steps. Most of those packs are not even presented here at all.
I'm about to build 3 20S3P packs for a friend for use on his 2WD hunting bike. He needs to double his capacity and has limited room to use for the pack. I have a triangular space to fill that is conveniently the right size for 3 20S3P packs side by side for a total of 20S9P.
I made this cardboard mock-up of the space to see what would fit here.
60 cells fit in there with a little extra space at the top...not bad! 3 of these will go side by side in the space.
I ordered Panasonic NCR18650B cells. I considered using 30Q's but this build doesn't need lots more current draw, just more capacity. 3400mah vs 3000mah won out. This is 256 of the cells. Before I begin building the pack all the cells will get tested to confirm capacity and Ir. Only the best 180 cells will get used for this pack. The rest...for who knows what.
I have a 20S smart BMS coming that I will mod for 200 amps. I need to order a few rolls of nickel strip and a corded spot welding pen. My spot welder won't reach into the center of these packs.
First step is to charge all the cells to 4.1v. 3 RC chargers all at once and 104 cells is going to go through them quickly. For testing, the iCharger 4010 DUO (upper right) is the best choice. On the 4010 is dual 10S 18650 battery holders. I can charge and discharge 20 cells at the same time. The ISDT D2 is charging 6S6P and 4S6P battery holder packs. The SkyRC D2 is charging 2 sets of 6S6P.
I'm about to build 3 20S3P packs for a friend for use on his 2WD hunting bike. He needs to double his capacity and has limited room to use for the pack. I have a triangular space to fill that is conveniently the right size for 3 20S3P packs side by side for a total of 20S9P.
I made this cardboard mock-up of the space to see what would fit here.
60 cells fit in there with a little extra space at the top...not bad! 3 of these will go side by side in the space.
I ordered Panasonic NCR18650B cells. I considered using 30Q's but this build doesn't need lots more current draw, just more capacity. 3400mah vs 3000mah won out. This is 256 of the cells. Before I begin building the pack all the cells will get tested to confirm capacity and Ir. Only the best 180 cells will get used for this pack. The rest...for who knows what.
I have a 20S smart BMS coming that I will mod for 200 amps. I need to order a few rolls of nickel strip and a corded spot welding pen. My spot welder won't reach into the center of these packs.
First step is to charge all the cells to 4.1v. 3 RC chargers all at once and 104 cells is going to go through them quickly. For testing, the iCharger 4010 DUO (upper right) is the best choice. On the 4010 is dual 10S 18650 battery holders. I can charge and discharge 20 cells at the same time. The ISDT D2 is charging 6S6P and 4S6P battery holder packs. The SkyRC D2 is charging 2 sets of 6S6P.
ElectricGod
10 MW
All the cells are charged. I'm now looking for any weak ones.
I first attempt was to discharge 20 cells at 2C or 7 amps, but like cells, the results varied somewhat and the test aborted too soon.
I then went to 1C or 3.4 amps and tried 20 cells again. The results were lots better.
I then tried .5C or 1.5 amps and that was not really an improvement over 1C, jsut took twice as long.
I'll be discharge testing these cells at 3.4 amps or 1C.
I really wish manufacturers didn't fake capacity specs! They all do it more or less the same way...so I guess they are all dishonest together.
These cells are rated for 3400mah
The only way you will ever see that is if you charge to 4.2v and discharge to 2.5v...something no one in the real world will ever do. Then you have to discharge at .25C...again something no one in the real world will ever do.
As a result, I'm seeing around 3000mah out of these cells by charging to 4.1v, discharging to 3.0v and 1C. AKA...something that could happen in the real world.
On the left is what is tested so far. On the right is what is waiting to be tested. This will take a while. I put 20 cells in the battery holder, start the discharge test and walk away. An hour plus later, I have capacity results. When I get home from work, I check the batch I left running before leaving for work. Then start up a new batch. In the evening, I can get 2 maybe 3 batches done. I'm looking at something like 80 cells tested in a day.
I first attempt was to discharge 20 cells at 2C or 7 amps, but like cells, the results varied somewhat and the test aborted too soon.
I then went to 1C or 3.4 amps and tried 20 cells again. The results were lots better.
I then tried .5C or 1.5 amps and that was not really an improvement over 1C, jsut took twice as long.
I'll be discharge testing these cells at 3.4 amps or 1C.
I really wish manufacturers didn't fake capacity specs! They all do it more or less the same way...so I guess they are all dishonest together.
These cells are rated for 3400mah
The only way you will ever see that is if you charge to 4.2v and discharge to 2.5v...something no one in the real world will ever do. Then you have to discharge at .25C...again something no one in the real world will ever do.
As a result, I'm seeing around 3000mah out of these cells by charging to 4.1v, discharging to 3.0v and 1C. AKA...something that could happen in the real world.
On the left is what is tested so far. On the right is what is waiting to be tested. This will take a while. I put 20 cells in the battery holder, start the discharge test and walk away. An hour plus later, I have capacity results. When I get home from work, I check the batch I left running before leaving for work. Then start up a new batch. In the evening, I can get 2 maybe 3 batches done. I'm looking at something like 80 cells tested in a day.
ElectricGod
10 MW
Cell testing has been ongoing. I've had 2 cells that are 2800mah and I'm about 450 cells in. The rest are testing pretty close to capacity so that I don't care.
ElectricGod
10 MW
Ianhill said:
Battery testing takes a good while! This is 3 layers of 133 cells or 399 cells on the left and 40 on the right...all tested. Another 160 to go. I got the cells for $4 each including shipping
ElectricGod
10 MW
Ianhill said:
No...2 packs...20S20P for me and 20S10P for a friend.
ElectricGod
10 MW
Ianhill said:
His pack is a secondary to another 20S10P he already has...just needs more current and range. He has a 2WD mountain climbing monster with 40 pound tires on it. He calls it the Mudworm. It's not fast, but it will dig out of 2 foot deep mud or climb a 45 degree hill. This is going from 8kw to about 12kw, RV-160SH rewind, Nucular 24 fet controller, bigger pack and a few other things.
https://www.youtube.com/watch?v=-oIEnukUpuE
My pack will go in the XB-502 in place of the LIPO's in there now. 3.4A at 20S is 68A, 2C is 136A, 3C is 204A. I won't need but maybe 80 amps. so far the worst I've seen is 70 amps on the HLD inrunner. That will go a little higher on the RV-120...once I get that done. The battery box has lots of wasted space due to the blocky nature of LIPOs. With 18650s fitted to the shape of the box, it can hold a good bit more capacity.
Ianhill
1 MW
- Joined
- Sep 25, 2015
- Messages
- 2,872
I like the mudworm, perfect name wriggles its way up everything in the video filthy stinking horrible trail too, there's a few local bike eaters close to me horrible they hide themselfs fields full of bog enter at own risk one wrong move and the bike is upto the handlebars airlocked in bog.
How much of a weight difference is there with the 18650 vs the Lipo, And then vs the added torque from the motor swap out will you have extra power or equalise power with the added weight but an exceptional jump in range.
Tab welding/ assembly now at least thats fairly fun compared to the testing you have completed fairplay you have really got into the guts of all the aspects of EV the controllers batterys motors and much more brought us all along for the ride appreciate it tought many lots few haters along the way but so did your son Jesus
How much of a weight difference is there with the 18650 vs the Lipo, And then vs the added torque from the motor swap out will you have extra power or equalise power with the added weight but an exceptional jump in range.
Tab welding/ assembly now at least thats fairly fun compared to the testing you have completed fairplay you have really got into the guts of all the aspects of EV the controllers batterys motors and much more brought us all along for the ride appreciate it tought many lots few haters along the way but so did your son Jesus
ElectricGod
10 MW
Ianhill said:I like the mudworm, perfect name wriggles its way up everything in the video filthy stinking horrible trail too, there's a few local bike eaters close to me horrible they hide themselfs fields full of bog enter at own risk one wrong move and the bike is upto the handlebars airlocked in bog.
How much of a weight difference is there with the 18650 vs the Lipo, And then vs the added torque from the motor swap out will you have extra power or equalise power with the added weight but an exceptional jump in range.
Tab welding/ assembly now at least thats fairly fun compared to the testing you have completed fairplay you have really got into the guts of all the aspects of EV the controllers batterys motors and much more brought us all along for the ride appreciate it tought many lots few haters along the way but so did your son Jesus
I'm pretty sure "up to the handlebars" will stop the mudworm too...even at 12kw. That's an insane amount of bog!
The LION pack will weigh a bit more, but it will also have almost double the capacity as the LIPOs. I'm mostly going for more range, but more motor power won't offend me either. 60mph top speed is fine. It's already faster than any moped on the road both accelerating and top speed. The bigger pack is mostly about riding 60 miles round trip on a single charge.
The RV-120 vs the HLD inrunner: Virtually the same size and weight, but lots more torque from the RV-120 after the rewind. That's generally true for outrunenrs vs inrunners anyway, but really good copper fill helps push that even higher. I'm not sure yet...haven't touched the RV-120 in months due to a scooter build from hell for a friend killing movement on everything else, but I'm expecting something like 10kw from the RV-120 once I get to use it.
Brought along for the ride...you are welcome. I post what I post so others can see and copy. I don't see myself as some epic know it all leader. More like an average guy doing stuff that most folks ought to be able to duplicate. I do have my haters! Go figure! Pretty sure I'm no deity, but thanks for comparison.
ElectricGod
10 MW
Ianhill said:
Cell testing is done! 600 cells took a looong time to get through.
hopefully this weekend, I'll be arranging cells for a pack and start doing some welding.
ElectricGod
10 MW
I'll make a frame out of wood to fit around this to hold them all tightly together. This is pretty close to the triangular shaped space I have to work with on my friends hunting bike and getting the maximum number of cells in there (60 each). I'll be welding up 3 sets of these to place side by side inside the space. Each sub pack will be 20S3P for a total of 20S9P.
Here's the space I have to fill.
Here's the space I have to fill.
ElectricGod
10 MW
The frame was easy to make. I ripped a section of 2x4 into 1/4" thick sections. It's a snug fit around the cells so they stay held together while being welded.
This is the cell layout for 20S3P. I went for the best layout to long straight lines of cells. One down...2 more to go!
Worked out pretty well. Batt + is at the sharp corner. Batt- is the other top corner.
FYI...don't let the nickel strip make contact to other cells, it will instantly weld itself down. This was at 15S...plenty of voltage and current.
This is the cell layout for 20S3P. I went for the best layout to long straight lines of cells. One down...2 more to go!
Worked out pretty well. Batt + is at the sharp corner. Batt- is the other top corner.
FYI...don't let the nickel strip make contact to other cells, it will instantly weld itself down. This was at 15S...plenty of voltage and current.
ElectricGod
10 MW
3 packs welded. 2 need to sit for a while so the silicon can cure since they got made no more than an hour ago.
I have balance and buss wires to make up yet. Lots more to do before this is a 10S9P pack.
I have balance and buss wires to make up yet. Lots more to do before this is a 10S9P pack.
ElectricGod
10 MW
I've been a battery pack making crazy man today. This is for a friend in NYC for his scooter build. I'm also modding a BMS and a C80100 for him. He gave me $$ to get him LIPO packs and to then set it all up for him.
All 8 packs have been tested to make sure they have the right capacity.
I first wrapped them together in stacks of two and then 4 to make each individual 16S pack. On pack has the wires all coming out at the center and the other at the edges. The packs has XT60's on them so one by one I removed a single wire from each pack and soldered the next pack wire to finally get the 16S series like this.
I then carefully routed the power wires and taped them down. This was probably not necessary, but I prefer making everything neat and tucked away.
Since it's 2 sets of packs that I needed to make into one, I cut a piece of plywood to mount them on. I'll need to make some Y cables for the balance wires and the 2 remaining XT60's will get a Y connector too so that both packs can be all in parallel.
All 8 packs have been tested to make sure they have the right capacity.
I first wrapped them together in stacks of two and then 4 to make each individual 16S pack. On pack has the wires all coming out at the center and the other at the edges. The packs has XT60's on them so one by one I removed a single wire from each pack and soldered the next pack wire to finally get the 16S series like this.
I then carefully routed the power wires and taped them down. This was probably not necessary, but I prefer making everything neat and tucked away.
Since it's 2 sets of packs that I needed to make into one, I cut a piece of plywood to mount them on. I'll need to make some Y cables for the balance wires and the 2 remaining XT60's will get a Y connector too so that both packs can be all in parallel.
Ianhill
1 MW
- Joined
- Sep 25, 2015
- Messages
- 2,872
Good thing by separating the packs apart is you don't have to double up on nickel the current is split amongst the 3 so am i right in thinking its got the current carrying capability of 3 pieces of nickel strip thick for the grouped bundles ?
Seems plenty enough I'd make sure the links are the same length to keep the resistance equal across the 3 stacks but you got it covered I'm sure your flat out there by the looks top work for the community and all.
I noticed there's a new torch on the block using a laser excited phosphor (lep) extreme narrow angle beam 500 lumens at 1 metre can throw 2km there's also another new one called lep again but this is a light emitting plasma modernised arc lamp but with high efficiency not to sure on how that one works but the lep is a blue laser shot at phosphor to create a white light and guided by mirrors to make an extremely powerful throwing light in a small form factor torch that just looks super impressive even in it's 1st stage down the line this could bring a handheld torch that could shine 10 miles or more.
Seems plenty enough I'd make sure the links are the same length to keep the resistance equal across the 3 stacks but you got it covered I'm sure your flat out there by the looks top work for the community and all.
I noticed there's a new torch on the block using a laser excited phosphor (lep) extreme narrow angle beam 500 lumens at 1 metre can throw 2km there's also another new one called lep again but this is a light emitting plasma modernised arc lamp but with high efficiency not to sure on how that one works but the lep is a blue laser shot at phosphor to create a white light and guided by mirrors to make an extremely powerful throwing light in a small form factor torch that just looks super impressive even in it's 1st stage down the line this could bring a handheld torch that could shine 10 miles or more.
ElectricGod
10 MW
I got the BMS set up today for that dual 16S LIPO set up I posted earlier. I've already modded the BMS for more amperage some time back. I have a thread on how to do that if you are interested.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=95853&p=1403576#p1403576
Today, I got the BMS wired up for power and so that it can monitor dual 16S packs in parallel. I reused 2 XT60's from the packs as shown above and then made a power cable that puts both those XT60's in parallel.
Power cables connected to the BMS. Both wires are 10 awg. The negative wire connects to the BMS via 5.5mm bullets.
I made up parallel 4S balance connectors for the BMS. Notice the numbering on the connectors. 1 is the LOW balance conenctors and 4 is the HIGH balance connectors on the individual 4S LIPO packs in the 16S strings of packs.
BMS connected to the dual 16S packs.
Balancing is pretty good considering these packs have never been balanced as a 16S whole before.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=95853&p=1403576#p1403576
Today, I got the BMS wired up for power and so that it can monitor dual 16S packs in parallel. I reused 2 XT60's from the packs as shown above and then made a power cable that puts both those XT60's in parallel.
Power cables connected to the BMS. Both wires are 10 awg. The negative wire connects to the BMS via 5.5mm bullets.
I made up parallel 4S balance connectors for the BMS. Notice the numbering on the connectors. 1 is the LOW balance conenctors and 4 is the HIGH balance connectors on the individual 4S LIPO packs in the 16S strings of packs.
BMS connected to the dual 16S packs.
Balancing is pretty good considering these packs have never been balanced as a 16S whole before.
Ianhill
1 MW
- Joined
- Sep 25, 2015
- Messages
- 2,872
https://www.autocar.co.uk/car-news/industry/williams-reveals-lighter-yet-longer-range-ev-battery-module
Have a read of that reminded me of your scooter running Lipo and laptop cell mix exact same thing being achieved capacity and discharge combined all be it they have limited the current flow between the two cells types with a dc/dc converter.
Have a read of that reminded me of your scooter running Lipo and laptop cell mix exact same thing being achieved capacity and discharge combined all be it they have limited the current flow between the two cells types with a dc/dc converter.
ElectricGod
10 MW
I got back to the 20S Mudowrm packs tonight. They all have balance and power wires on them now.
They all have balance wires and power on them now. I have 21 unique colors here.
There's an under layer on each side that separates the wires from the nickel strips so that the wires can't short on anything. This will prevent any abrading of the wires on the nickel strips.
Each pack is enclosed in 2 layers of closed cell foam and then wrapped in kapton tape.This ought to protect all the surfaces from shock and bouncing.
They all have balance wires and power on them now. I have 21 unique colors here.
There's an under layer on each side that separates the wires from the nickel strips so that the wires can't short on anything. This will prevent any abrading of the wires on the nickel strips.
Each pack is enclosed in 2 layers of closed cell foam and then wrapped in kapton tape.This ought to protect all the surfaces from shock and bouncing.
ElectricGod
10 MW
Ianhill said:
Yes...you are right...it's just a dual chemistry pack.
Depending on what kind of batteries and money I have on hand for my next build, I may be building from LION, LIPO and LTO to get the capacity I need. At 131v, have enough LTO to make 33Ah. In LIPO, 16 or maybe 32Ah and in LION...lots and lots of used 18650's.
