VX1 Li Ion 18650 conversion

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prensel
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VX1 Li Ion 18650 conversion

After searching a couple of weeks it seemed that a Leaf conversion was not so easy because these cells/modules are very hard to find.
Apart from that the Leaf option would only bring me 60Ah and about 100km usable distance per charge.

Because I wanted more I decided to go for the Li-Ion route with my own to assemble pack made of hundreds 18650 cells ;-)

The parts that I would need are:
- many many cells of the type 18650
- CD tab welder
- nickel strips 0.15mm
- busbars 4mm diameter of pure copper
- hotmelt glue pistol and glue sticks
- some soldering iron
- a LOT of time... but thats was just a guess ;-)

I ended up by buying 1050 cells of the Samsung 29E type. These are 3.7V and 2850mAh.
This would build me a 35S30P pack, so 35 cells in series and 30 cells in parallel.
In total 130Volt and 85,5Ah pack which would mean about 150km of distance. Now we're talking :-)

Yesterday the cells arrived. Well not all of them, the first batch of about 800cells. The rest is to expect next week.
Because of that i decided to build rows of 8 cells each instead of 10 cells.
Three of these rows would be parallel connected to create what i call a module. Each module is then 3.7V and 68Ah (with 8 cells) or 85,5Ah (with 10 cells)
For the busbar connection between the modules I would use 2 * 4mm copper wire. This would be enough for about 240A maximum.

I had a hotmeld glue pistol but that was just a small kinda thing with 7mm gluesticks. So I decided the spent some serious money and bought a brand new 11mm hotmelt gun at the Action store for just... €2,39...
Well for that kinda money why not buy some pack of 10 sticks for just €0.99. per pack with it...

I first created some stand to hold 3 rows of cells. This way I could line-up, glue and cool down 3 rows of cells at the same time.

foto-1.JPG

By glueing 3 of these rows together would create the module.

foto-2.JPG

Lateron I will add the nickel strips and busbars and probably shrink-wrap each module.

BLUESTREAK
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Re: VX1 Li Ion 18650 conversion

Now that is going to be a lot of work but you just the man to do it, please keep us posted with photos of your assembly. I sent you a PM about the item's and hope you have good fortune with your build.

pavlom
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Re: VX1 Li Ion 18650 conversion

Really interesting. How much are the 1050 cells?

prensel
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Re: VX1 Li Ion 18650 conversion

Really interesting. How much are the 1050 cells?

I have paid €2,40 per cell.

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

Bikemad
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Re: VX1 Li Ion 18650 conversion

Later on I will add the nickel strips and busbars and probably shrink-wrap each module.

Hi Paul,
I don't know if you've already seen the following video but you might find it very interesting if you haven't:

Apparently, it is done differently on the Tesla battery packs, instead of using high current nickel links on each of the modules, they are simply joined to a common high current bus bar using small fusible wires that only need to carry the current from each individual cell in each module.
This allows the wire to fuse if a fault develops on an individual cell so that it is automatically disconnected from the circuit instead of drawing excessive current, generating unwanted heat and discharging the other good cells in the module.

If you used 10A fuse-wire to connect each of the cells in your 24 cell modules to a common bus bar you would still be able to draw up to 240A from your pack without worrying about the fuse-wires blowing. The motor controller only has a 200 Amp fuse, which should be the weakest link.

You might want to consider implementing something similar while building your pack modules.

35 in series seems a bit low (147V max) compared to the typical 18 leaf modules (36 Cells in series). Is this because of space limitations?

Alan

prensel
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Re: VX1 Li Ion 18650 conversion

If you used 10A fuse-wire to connect each of the cells in your 24 cell modules to a common bus bar you would still be able to draw up to 240A from your pack without worrying about the fuse-wires blowing. The motor controller only has a 200 Amp fuse, which should be the weakest link.

You might want to consider implementing something similar while building your pack modules.

35 in series seems a bit low (147V max) compared to the typical 18 leaf modules (36 Cells in series). Is this because of space limitations?

Ah yes, i totally forgot about this video. I've seen it a while ago and actually forgot about it.
I have been thinking about using fuse wires and i really like that idea.
Tomorrow i'll be receiving my other few hundred cells so the packs wil be 3*10 cells each finally. This means that a fuse wire of about 8A is enough for 240A max. Well for use in the Vectrix that is but i'll go for 10A fuse wire which is also the max current allowed from the cells. That way i could always use the modules for something else if i wanted to.
I've also ordered another 30 cells extra to have the 36th module :-) the space is there, the BMS does support 36 modules so it would be a waste not take advantage of that.

Last night i finished glueing all available cells into modules. it has taken me about 5 hours in total for almost 800 cells.
Now i need to find some fuse wire and start soldering instead of welding :-)

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

MEroller
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Re: VX1 Li Ion 18650 conversion

Now i need to find some fuse wire and start soldering instead of welding :-)

Methinks the fuse wire should be spot-welded to the cell terminals, not soldered?

My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW

prensel
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Re: VX1 Li Ion 18650 conversion

I finished glueing the remaining 300 something cells yesterday so ended up with 'slabs' of 10 cells each.
Three of these 'slabs' or glued together into the final modules of 3*10 cells. I now have 36 of these.

These modules are 3.7V / 85,5Ah each.

3 * 10 modules

To monitor each of these modules i've ordered three Zeva BMS12 modules which will be integrated into my 'Magic Box' solution so they are CAN controlled.

Methinks the fuse wire should be spot-welded to the cell terminals, not soldered?

I've decided to use 0.16 * 5mm or 6mm nickel strips instead of solid fusewire.
These nickel strips will stand up till about 8Amps or 10Amps and i think is better to weld these to the cells than to solder solid 1mm fusewire

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

prensel
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Re: VX1 Li Ion 18650 conversion

I was recommended to add and extra ring of protection on top of each cell.
Reason was that the only thing to separate the negative outside of the cell to the positive tap on top was the small white ring and shrink tube.
So I drew up some template in Adobe Illustrator and cutted some black sticker on the sign cutter.

I think the result is fine :-)

18650 cell sticker

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

BLUESTREAK
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Re: VX1 Li Ion 18650 conversion

REALLY NICE.

Jonathanm
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Re: VX1 Li Ion 18650 conversion

I think there are many people really interested in what you are doing - I for one certainly am - please keep up the pictures + I'm very interested to know exactly how you are going to weld the wire/straps to each battery pole... because that is what can take all the time...

Good luck and please keep the information flowing.

Jonathan

prensel
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Re: VX1 Li Ion 18650 conversion

Thanks for the interest.

I'm currently waiting for the spot welder, nickel strips and shrink tube to arrive.
This probably takes a week or two.
In the mean time i'm working on installing a bigger charger and programing a controller to drive the charger and the dashboard.
I'm using a ThunderStruck TSM2500W CAN enabled charger of which 4 can be paralleled upto 10kW. If I only had the space for that....

As you can see the TSM2500 charger is almost a drop-in replacement for the original charger.

TSM2500 CANBUS charger in Vectrix VX1

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

Jonathanm
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Re: VX1 Li Ion 18650 conversion

I had not seen that model of charger before...I have only used the Elcon/TC chargers...which incidentally I see are also for sale on the Thunderstruck page...again please keep showing the progress....Tesla like battery conversion looks very interesting...

prensel
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Re: VX1 Li Ion 18650 conversion

As told before I'm currently in the 'waiting-mode' for some essential parts to arrive.

Regarding the spotwelding I followed some threads on the Endless-Sphere forum like http://endless-sphere.com/forums/viewtopic.php?f=14&t=68005
and decided to order the JP Spotwelder made by Jakov from Croatia.
This is 12V battery based welder and looks very nice and comes completely build. Welds with this device have been made (by others) for 0.15mm nickel so i have no reason to believe this wouldnt work for me. It works with a little timer device which controls the double welding pulse. With double pulse the first pulse cleans the material and the second pulse is the actual welding pulse.

I also noted the Zeva v2 spotwelder made/designed by Ian Hooper http://www.zeva.com.au/Projects/SpotWelderV2/. This is a DIY spotwelder based on using 24 or 30 big capacitors in parallel without any timing or double pulse involved. Its just a matter of 'charging' the capacitors and dumping all this energy in one go in one 'pulse' onto the nickel strips. According to the Zeva website this works very well. Reason enough for me to have the PCB's for this device produced by Seeedstudio (Gerber files are supplied by Zeva) and to order the remaining parts to build one of these spotwelders.

Because the JP welder comes with footswitch and electrodes I can use these for testing out the Zeva welder as well.
Plan is to do some test welds with both welders and see which works best.
I have about 1080 cells * 2 sides * 2 welds = 4320 welds to do so i want to do it right :-)

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

Jonathanm
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Re: VX1 Li Ion 18650 conversion

FYI - there are many DIY spot welders - the majority made from transformers and various parts from old micro wave ovens - look on youtube - quite a number of them appear to function very well...

zeuz
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Re: VX1 Li Ion 18650 conversion

In the mean time i'm working on installing a bigger charger and programing a controller to drive the charger and the dashboard.

Don't forget that Dugas Engineering and Vectrix 3.0 have custom firmware for this situation... ;)
prensel
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Re: VX1 Li Ion 18650 conversion

Finally today my nickel strip arrived from China.
Last week the spot welder and shrink tube had arrived and i found some solid 16mm2 copper for the busbar, enough for 160Amps each.

So today I continued working on the modules.

Because the nickel strips cannot be welded to the solid copper with the spot elder i needed to solder them.
First i created a jig with my router and some pieces of leftover Trespa board. I cutted 10 slots of 0.5mm depth and with equal distance of 18.3mm.
The nickel strips where placed into the slots and the busbar could be soldered on to them.
I ended up with something that looked like a piece of railroad track :-)

Busbar with nickel strip

Then the 'railroad tracks' are spot welded on the modules and there we have the first modules ready to be used.
The spot welding is very easy to do. I first tried some test pieces of strip to see which welding time was best and ended up around 12mS per weld.
It actually takes more time to cut and solder the nickel trips and busbars than to weld the 120 spots on each module.

Module with busbar

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

BLUESTREAK
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Re: VX1 Li Ion 18650 conversion

This is going to be one nice job, you have good hands and a sharp brain to do this. keep us posted although, I have my leaf conversion I still like to see other battery set-up's.

LithiumVectrix
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Re: VX1 Li Ion 18650 conversion

Hi Prensel,
This build looks similar to the Vectrix I built in 2013. It was built with the Panasonic CGR18650CG batteries as used in the Tesla Roadster.
http://www.evalbum.com/preview.php?vid=4802

oobflyer
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Re: VX1 Li Ion 18650 conversion

In total 130Volt and 85,5Ah pack which would mean about 150km of distance.

I'm also curious about the voltage. My Li-ion conversion has 42 cells (CHL LiFePo), 3.65V each, all connected in series for a total voltage of about 153V (50AH). The original NiMH pack had similar voltage.
Will the lower voltage lower the "horsepower" of the bike?

Love the capacity - 85AH!

LithiumVectrix
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Re: VX1 Li Ion 18650 conversion

Hi oobflyer,
The 130 volts mentioned is the nominal voltage of the battery pack. This is different to the voltage of a fully charged battery pack.
The original NiMH batteries nominal voltage was 102 cells x 1.2 volts = 122.4 volts. When fully charged this battery reaches 102 x 1.49 volts = 152 volts.
Your LiFePO4 battery nominal voltage is 42 cells x 3.2 volts = 134.4 volts. This battery can safely charge to 42 x 3.65 volts = 153.3 volts.
The batteries that Prensel is using are NMC batteries commonly used in Ebike battery packs.
LiNiMnCo batteries are nominal 3.7 volts per cell. 35 x 3.7 volts = 129.5 volts. When fully charged this battery reaches 35 x 4.20 volts = 147 volts.
The regenerative braking on the Vectrix will reduce progressively at voltages over 146 volts. The 35s setup matches the voltage range of regen braking, nominal voltage and motor controller low voltage battery protection correctly.
From my experience the 85.5 Ah battery pack will give a range of 210 - 220 km at a constant 60 Km/Hr.

Kocho
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Re: VX1 Li Ion 18650 conversion

With the availability now of customized motor controller software from www.vectrixsupport.com, I think opting for higher pack max. voltage is advantageous, while low voltage protection in use is still possible. The bike just feels more powerful when fully charged vs. when half-charged. Might be my imagination, but I think mine's zippier at 146V than at 130V... Plus the battery is charged to lower levels than max, which is supposed to be good for it.

Without mods, the factory MC software on mine noticeably starts to auto-protect from low voltage at something around 118V and stops the bike around 115V if I remember right. I think power begins to be limited even a couple of volts earlier. I forgot which version MC software I'm running, but I'm pretty sure it's a late revision Li one. That's a safe level for the 18 cell Nissan Leaf conversion that I have. Regen is weak after my "full" charge at 146V, but by 144V or so (which comes pretty soon as the discharge curve is steep there) regen seems back to normal.

LithiumVectrix
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Re: VX1 Li Ion 18650 conversion

I agree that the best setup when using Leaf battery blocks is 18 blocks. This is a 36s setup. Works well in the Vectrix VX1.

Kocho
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Re: VX1 Li Ion 18650 conversion

I was actually suggesting that 19 would be better :) I went with 18, because at the time I was not sure if the MC software would be modifiable or not and I wanted to have some low voltage protection from the OEM controller software. I think, if the MC low voltage limit can be raised, then 19 modules would be better - charged to a little lower SoC than the 18 would be (but perhaps a bit higher voltage), so the top voltage will still be something like 146-150V but that would be a lower SoC than 150V is on the 18 module setup. So the battery would be less stressed when charging, and will be in the more linear section of the discharge curve so the voltage will stay high longer than with 18 modules...

Probably splitting hairs anyway. I'm very happy with the 18 module setup. If I had 5-10mph higher top speed it would be perfect. With a max of 68mph I'm relegated to the right two lanes (that's the slow lanes for those of us who drive on the proper side of the road ;) ) when traffic is light, and I think the bike could probably safely handle bursts of higher top speed on flats and downhill without overstressing the electronics.

I agree that the best setup when using Leaf battery blocks is 18 blocks. This is a 36s setup. Works well in the Vectrix VX1.

prensel
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Re: VX1 Li Ion 18650 conversion

Okay, vacation has ended so back to 'work'...
After almost 4 weeks in France i returned with another project: Citroen Saxo Electrique.

Citroen Saxo Electrique

This is one of the original by Citroen factory converted cars. About 450 of these Saxo's Electrique were made between 1997 and 2002.
I will be converting this from 100Ah NiCd to about 260Ah Lithium.

But first back to the Vectrix conversion:

I finished up welding, soldering busbars, connectors, re-soldering connectors because of a mistake etc etc and finally ended up with 36 of these nice modules.

Li-ion blok 85Ah

These all fit very nicely in 9 rows of 4 blocks each in the Vectrix chassis.
Before putting in the 36 blocks i have padded the box with 5mm rubber plates and 2mm polystyrol plates.
So the whole pack of blocks is electrically isolated and protected against vibrations.

blocks in chassis

Then I realized i had made a BIG mistake.
I had totaly forgotten to pack each cell in shrink tube and additionally added protection on the top ends.
How i found out ?

Well look at this as two adjacent blocks had apparently damaged the cell plastic and touched each other and big sparks flew around.

Cell damage

So at this time i'm taking all blocks out of the chassis and will cover them with shrink foil and separate all 4 rows of cells with additional polystyrol separator plates.

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

LithiumVectrix
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Re: VX1 Li Ion 18650 conversion

I have used an insulator between the rows. I cut them from sheets of plastic to separate the rows.

prensel
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Re: VX1 Li Ion 18650 conversion

This is how i'm doing it now:
Both sides of the blocks are covered with an 1mm carton cover and then shrink-wrapped.
So now every block is separated from the adjacent one with 2mm of carton and 2 layers of shrink-wrap.

packing blocks

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

BLUESTREAK
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Re: VX1 Li Ion 18650 conversion

Very nice work,keep us posted since we all are interested in your build.

Kocho
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Re: VX1 Li Ion 18650 conversion

EDIT: after I wrote the below, I see you seem to have something between cells in a block - can't see well from the photos...

I'd be a bit worried about something like this happening between cells in a group. Especially, the ones near the bottom, where the rest of the cells push on them from above.

Also, I suppose, heat-up may not be a huge issue in the Vectrix where currents are not huge vs. these cell capacities. Still, the cells touching each other and being shrink-wrapped and triple-insulated will keep them from dissipating heat. You save space by not having a plastic separator honeycomb-like structure where each cell is locked, but will it work safely without it?

Then I realized i had made a BIG mistake.
I had totaly forgotten to pack each cell in shrink tube and additionally added protection on the top ends.
How i found out ?

Well look at this as two adjacent blocks had apparently damaged the cell plastic and touched each other and big sparks flew around.

Cell damage

So at this time i'm taking all blocks out of the chassis and will cover them with shrink foil and separate all 4 rows of cells with additional polystyrol separator plates.

MEroller
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Re: VX1 Li Ion 18650 conversion

Kocho, every cell block has ALL cells facing the same way, they are all in parallel, so their cases are already all connected via the minus bus bars ;-)

My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW

prensel
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Re: VX1 Li Ion 18650 conversion

All modules ready to be installed.

Blocks to be installed

===================================
My contribution to EV in The Netherlands
- Novox C20
- Vectrix VX-1 Li+ my2009 #2791
- Vectrix VX-1 Li my2011 #3228
- CityEl Fact4 / Mini El Cabrio
- Th!nk PIV4 A266
- Th!nk City A306
- Tesla Model3 AWD

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