PINNED - Lithium battery conversion/info

[expresso]

Shirleys BMS is better. But if its too complicated to connect, or too complicated to wire up, the packs that are ready built from evassemble already include a BMS that will work. Those just need to be bought and then plugged in to your chair.

Theres a 100 ways to do things. Thats the simple plug and play way. Its less good for a number of reasons. But should work in a fashion. And it will charge fine with your existing charger. While plugged into your chair or otherwise. EVAssemble will probably fit your Anderson 50 connector(s) as needed. Or you can.

After this, IF YOU WANT there are better ways. Better or bigger packs. Better lower charge voltage and higher Amp BMS boards, and so on.

Personally I would not use a BMS at all as they are all pretty crap and simply charge with a hobby charger instead and then its even more simple to use 2 OR 4 hobby king ready to go high rate 30C 8.4Ah 12V packs...

Or build a full proper 100Ah plus battery. And use a hobby charger. OR a dumb charger and shirleys low charge voltage type BMS. But a bigger higher Amp one.

Theres only so many ways or times you can say the same things! You must understand the reasons. Then this will all make obvious sense. Which is why I say you should read every post in this thread.

yes your right - i am going to start to read this section from the start - so i have a little understanding - this BMS thing is throwing me off some - i understand it balances the cells during charging and usage - - protects them etc, - and you also say they are no good and you dont use a BMS - - so in a pack with no BMS - is it more dangerous ? what do you loose out if you dont use a BMS -

i think i may just give this one a try http://www.evassemble.com/index.php?mai ... ucts_id=56

since i can just plug it in and thats it - i will get there charger also and charge it separate from the chair to get it to 29.2V and plug it in when i use the chair again - this has a built in BMS - and the only thing i need to do is make sure the connection has a SB 50 connector so i can just plug it in -

now i am still back to my charging cable - the cable i have on my chair direct with SB 50 is 10 guage with a 30 amp fuse - i use the 20 amp charger there and never had a issue -

now if i get this pack and use it plug it in and go out riding - is this going to be a problem - ?

so if i get this battery pack - and this charger - for this pack alone - one of these chargers - and the battery pack - 20 ah model - or if theres any reason to get the 15ah model instead - other than the cost difference ?

http://www.evassemble.com/index.php?mai ... ducts_id=6

http://www.evassemble.com/index.php?mai ... cts_id=167


i am still not sure the battery pack has two sets of wiring coming out of it - shouldnt i just need one cable with a SB 50 on the end only coming from the battery pack ?

[Burgerman]

yes your right - i am going to start to read this section from the start - so i have a little understanding - this BMS thing is throwing me off some - i understand it balances the cells during charging and usage - - protects them etc, - and you also say they are no good and you dont use a BMS - - so in a pack with no BMS - is it more dangerous ? what do you loose out if you dont use a BMS -

You lose nothing. Other than complications and extra wiring, and more to go wrong, usually shortened cell life as they tend to let the high cells bounce of the voltage limit for long periods while it feebly attempts to balance the battery, and the BMS cutting power inadvertently, in the wrong places and for the wrong reasons. PROVIDED you use a quality cell balancing charger, and use correctly sized, and correct C rated cells, and don't discharge them too low a hobby charger is easier, simpler, less to go wrong and it never lets your cells go over voltage and has 10x the balancing power as well as proportional power output to prevent the on/off cycling that causes the damage... But either will work.

Read... http://www.wheelchairdriver.com/BMS.htm Shirley gets over most of these problems by using a lower voltage charger, (to stop the cells repeatedly going over 3.60V) and by bypassing the part of the BMS that cuts power if you take a lot of Amps, or if voltage drops under load etc.

since i can just plug it in and thats it - i will get there charger also and charge it separate from the chair to get it to 29.2V and plug it in when i use the chair again - this has a built in BMS - and the only thing i need to do is make sure the connection has a SB 50 connector so i can just plug it in -

You DO NOT WANT 29.2V. I repeat myself endlessely. It will shorten the cell life and ruin the battery if used with a generic BMS... Use your mobility charger.

now i am still back to my charging cable - the cable i have on my chair direct with SB 50 is 10 guage with a 30 amp fuse - i use the 20 amp charger there and never had a issue -

As I already said (twice) Your chair CAN take much more. How much we don't know because we cannot know the battery internal resistance, you motor current draw etc. But it needs to be bigger. Fit a larger fuse if it blows. Or fit a larger one before it does.

now if i get this pack and use it plug it in and go out riding - is this going to be a problem - ?

With a BMS and a small fuse, the add on may cut out due to BMS limit, or fuse may blow. Or it may be fine. I would have no BMS and also bigger fuse. Then no problem. But I already said this previously.

so if i get this battery pack - and this charger - for this pack alone - one of these chargers - and the battery pack - 20 ah model - or if theres any reason to get the 15ah model instead - other than the cost difference ?

http://www.evassemble.com/index.php?mai ... ducts_id=6

http://www.evassemble.com/index.php?mai ... cts_id=167

You do not WANT that charger...
15, 20? Weight, size, range, only difference.

Two wires coming out?
One goes to charger through the BMS (which I wouldn't use) and the other goes to the chairs power. The BMS interferes with them both differently. It allows a 2 wire dumb charger to be used. And the one you have is the one you need.

[expresso]

Ok so what should i do to make it simple and easy for me to do this ADD on -

Should i get this pack - ? and just plug it in - charge with my charger i have now and thats it -

do i just not connect the BMS wire to nothing ?

http://www.evassemble.com/index.php?mai ... ucts_id=56

the fuse i have is this one -

[expresso]

the wire i know is 10 guage about 3 feet - - with a SB 50 on the end - and that fuse on the battery with a fuse block -

i would like to not have to change anything there if i really dont need to - because i have to take the chair apart and i cant do that - - i then have to get a new wire and connector etc - since i had the wires done for me -

i mean if i have no choice - i will do it - but if i can get away with what i have already connected - its easier for me -

Happy Thanksgiving by the way - to everyone here -

[Burgerman]

A fuse may often take more than 30A INTERMITTENTLY. Sometimes much more like 60 or 80A So it may work fine.

If it doesent you wont break down, you just lose the extra add on power. Thats the only way you will know.

You can connect the BMS charge wire to your charger if you want. If the pack is plugged into your powerchair that will charge your lead battery too.

[shirley_hkg]

You'd better have the 2 batteries stay connected, during charge and discharge.

[expresso]

A fuse may often take more than 30A INTERMITTENTLY. Sometimes much more like 60 or 80A So it may work fine.

If it doesent you wont break down, you just lose the extra add on power. Thats the only way you will know.

You can connect the BMS charge wire to your charger if you want. If the pack is plugged into your powerchair that will charge your lead battery too.

i Started to read the section from page one yesterday - and i decided that i want to do the ADD on pack only for now - since its easier for me to get started and learn as i go with a small pack - and two - since i get new lead batteries paid for -
no reason for me to spend more than i have to - and i can use on either chair this way -

so i am ready to purchase what ever i need to do this - and what do you think i should do - Get the ready made pack http://www.evassemble.com/index.php?mai ... ucts_id=56

or should i get the 8 cells and make it - or try 16 cells - all depends how large would a 16 cell pack end up to be ? i want to fit this pack in my napsake that i hang on my chair in the rear -

i can try 8 cells first and then add 8 if i see it fits

or just get the ready made pack from the link above ?

i am still confused about this BMS charge wire sticking out of the battery pack - where do i plug that in ? my charger dosnt have a place for that - so i am confused what i do with that wire -

i just want to get started and get the parts or the ready made pack - which ever is easier - better etc, -

[expresso]

You'd better have the 2 batteries stay connected, during charge and discharge.

What do you mean ? i was going to disconnect the add on pack - and charge the chair normally - and charge the pack seperate - i would get the hobby charger if i have to and use that one for the add on pack -

how would i charge the whole system with the add on pack connected to the cable i would have used to fast charge with ?

of i have to use the slower charger in the joystick port ? and leave it all connected - but the chargers go into float mode - is that ok for the add on pack ? to keep it trickle charged that way ?

i really do want to get started with this add on - either the ready made pack 20ah - or the 8 cell or 16 cell you showed me a few links back with the BMS you showed me - which i will have to be walked thru what i do with that and how i connect it etc, since thats throwing me off - but i am sure once its done - i will see it and understand it as i do it with your help of course

[Burgerman]

Your choice. I cant tell you whether to buy a Ferrari or a skoda or a truck or a 4x4. Its up to you how much battery to add, BMS or not, etc. And it depends on how much of this stuff you can do yourself, understand, etc.

Personally I wouldn't want or need a BMS and would use a hobby charger. Because its simply a better, safer, simpler way. And I wouldn't bother with an add on, because if you can fit that you can fit a full lithium battery because its exactly the same thing but 3x better!

The spare cable where is where you plug in the charger to charge BOTH batteries at once...

[expresso]

Your choice. I cant tell you whether to buy a Ferrari or a skoda or a truck or a 4x4. Its up to you how much battery to add, BMS or not, etc. And it depends on how much of this stuff you can do yourself, understand, etc.

Personally I wouldn't want or need a BMS and would use a hobby charger. Because its simply a better, safer, simpler way. And I wouldn't bother with an add on, because if you can fit that you can fit a full lithium battery because its exactly the same thing but 3x better!

The spare cable where is where you plug in the charger to charge BOTH batteries at once...

ok i see -- so the two cables coming out of the battery pack - one end goes in my cable on the chair and the other i just leave there and use that one to charge ?

thats simple enough - and that would charge all the batteries connected - -

i dont mind doing the hobby charger - at least just to get started i want to try something easy for me - with me having to do much - if i have a good experince and i feel i can more later on - i can think about doing a full set on my other chair one day - but like i said - its going to cost me about $2000 - i first have to be sure how many cells fit in my chair space - then the money and the work - which is fine - if i had to pay for the lead batteries - would be smart to do it - but
the add on may be enough if it can get me thru my day with having to worry about charging during the day - and just charge at night - that would work for me also

can i use a 20 amp charger if i connect the add on pack all connected to my chair etc, or is that too much for the add on ?

[Burgerman]

Read the BMS/Battery spec on the one you will be fitting. One of those specs will be max cont charge rate. If it higher than your charger, then yes.

EG, THIS http://www.evassemble.com/index.php?mai ... ucts_id=56
Says 20A.

So SHOULD be OK but I don't trust BMS...

[expresso]

Ok i think this pack may be the best thing for me to try as a first timer and beginner at this - - how would i know if the BMS in this pack goes back or acts funny etc, -

when i have this pack connected to my cable and charge the whole system together with a 20 amp charger -- do i leave it connected the charger once it goes to green - the way i do it now is i leave it connected 24 7 to the chargers

but is that ok when i have the add on also or do i have to stop it once its green ?

i want to be safe - watching the videos on utube - i seen some you posted and others showing the overcharging of the headways etc, - exploding -

also i would leave the add on pack when its charging in my backpack - is that ok - wont get too hot etc, Safely first -

[Burgerman]

Ok i think this pack may be the best thing for me to try as a first timer and beginner at this - - how would i know if the BMS in this pack goes back or acts funny etc, -

You get to throw away all the cells.
The way that a BMS works will probably mean this happens anyway sooner rather than later! Thats why those that understand lithium call them Battery Massacre Systems!

LiFePO4 Doesent burn or explode. All the fires and problems are usually BMS wiring or the BMS itself.
Yes leave it connected and charge as you normally do.

[expresso]

http://www.evassemble.com/index.php?mai ... ucts_id=18

if i went with 8 of these - how much AH extra would i get ? maybe i can do 8 and not use a BMS ? - charge with the charger you tell me - i will get that also - - disconnect from cable - charge separate or try to do what shirly posted about his BMS -

but i have option to not use a BMS with the Cells this way - ?

would this give me about 15ah or 20ah - ?

also what is the model of the hobby charger that i should get to charge them if i went with the cells

[Burgerman]

Hobby charger means no BMS needed. Any hobby charger will charge them as long as it does LIFE cells and 8S.

But a GOOD hobby charger is far more capable, complex, can charge anything, can be controlled and set up via PC, and has more settings options. It can charge from a power supply, or a car, and at up to 40 Amps. Lead, or lithium, or anything else.

I use a Cellpro PL8. I f you do this, you would be easier to use the packs from hobbyking as they are all pre wired and have correct connectors on the balance wires all ready to go. You would just need an adapter making to go to Anderson on your chair.

2 of these gives you 24V and 8.4Ah
4 of these will give you 24V and 17Ah extra.
http://hobbyking.com/hobbyking/store/__ ... _Pack.html These are high rate 30C packs.

They would only need a 5.5mm bullet to Anderson 50A connector cable making up. And all balance connector plug/socket already fitted to suit charger board. You just plug it in.

Charger... http://www.revolectrix.com/pl8_description_tab.htm
Will charge ANYTHING you have or buy. Very configurable. But you must configure it correctly at least once! Then save it. Again millions of hobbyists have no problem. Some do... Download and read its manual. Download the software, click advanced and take a look at the settings...

[Burgerman]

expressos head will explode soon...

http://revolectrix.com/support_docs/item_1437.pdf Charger manual. This will show you what the charger can do.

Once configured it means pressing a button twice to charge so dont let all that stuff scare you.

[expresso]

Hobby charger means no BMS needed. Any hobby charger will charge them as long as it does LIFE cells and 8S.

But a GOOD hobby charger is far more capable, complex, can charge anything, can be controlled and set up via PC, and has more settings options. It can charge from a power supply, or a car, and at up to 40 Amps. Lead, or lithium, or anything else.

I use a Cellpro PL8. I f you do this, you would be easier to use the packs from hobbyking as they are all pre wired and have correct connectors on the balance wires all ready to go. You would just need an adapter making to go to Anderson on your chair.

2 of these gives you 24V and 8.4Ah
4 of these will give you 24V and 17Ah extra.
http://hobbyking.com/hobbyking/store/__ ... _Pack.html These are high rate 30C packs.

They would only need a 5.5mm bullet to Anderson 50A connector cable making up. And all balance connector plug/socket already fitted to suit charger board. You just plug it in.

Charger... http://www.revolectrix.com/pl8_description_tab.htm
Will charge ANYTHING you have or buy. Very configurable. But you must configure it correctly at least once! Then save it. Again millions of hobbyists have no problem. Some do... Download and read its manual. Download the software, click advanced and take a look at the settings...

Sounds Great - and i am going to do it - if i have to do it - i think 4 would be the least to use to get any extra range out of it - but let me ask you this now - is this better or easier lets say etc, - than doing it with this Cells ?

http://www.evassemble.com/index.php?mai ... ucts_id=18

the Zippy batteries - i wont need a BMS or anything - but i have to disconnect from my cable on the charge and charge on its own - and chair separate ? i have to use the charge you linked me too - - i cant use my chair chargers that i use now ?

i want to get started and order something already - how do i connect the 4 batteries to each other ? to make one large pack - do would plug in to each other ?

either way i be back to ask questions once i get it in my hands to start - but right now - what are the pros or cons for each set up - 4 of these http://hobbyking.com/hobbyking/store/__ ... _Pack.html or 8 cells of these ? http://www.evassemble.com/index.php?mai ... ducts_id=1

[Burgerman]

I don't know where to start. We have been over all of this. And its all repeated in this thread in other places. And in different threads.

Ask a specific question and I will try and answer. As far as I see, its all easy.

EG "how do I connect 4 together". 2 in parallel, and 2 in series.

I would just make a bit of cable with an Anderson one end, and four 5.5mm bullet connector pairs on the other. Then plug into the chair. Yes you would plug 1 or 2 (or all 4 at once) into the charger. And charge in parallel at the same time at 30Amps and watch, monitor and control if you wish on your PC... No you cant charge those with your mobility charger. Yes they are 30C so better quality than the 10c Headway cells. You could charge the headways the same way, and use no BMS too.

The thing is you need to UNDERSTAND all of this to be able to decide. Don't buy, read! Go to a basic site that explains how to connect cells, batteries etc. Like http://scriptasylum.com/rc_speed/lipo.html And spend some time with the interactive stuff, and read it all twice! Then you will know the answers to your questions.

And read this thread too: viewtopic.php?f=2&t=5534&start=40

If you don't it will likely all end badly. If you do you will see how it all works!

[expresso]

i mean about the connections - was if they all plug into eachother with the plugs on the ends - so if i get 4 i can just plug them into each other - thats what i was asking - and yes i do have to read up on the connections etc, - i never done these hobbies so no experince -

and they are not cheap so i would be investing $400 on 4 batteries - plus the cost of charger - and i am ok with it - as long as i get it done right and it works for my needs -

the headways are cheaper overall cost - this is why i was curious what 8 Headways cells gives me in terms of Ah - how much extra - etc,

actually one review and it went up in smoke - not a good review - hope i dont get duds if i order them

http://hobbyking.com/hobbyking/store/uh ... duct=58820

[expresso]

For one moment - Lets say - i get the ready made pack - http://www.evassemble.com/index.php?mai ... ucts_id=56

i would just need to make two cables - one for the connection to my chair cable - i have already - and the other cable to charge it with - i can use my charger i have already 28.8V -

now if i am riding - and like you say - the BMS Can cut off power to the cells etc, etc, - the power would restore once it get lower - but if it cuts the power to the ADD on pack - the batteries in my chair - LEAD - would still work and chair wont stop ?

is that correct - or unless the chair is running off the battery pack alone - then it would stop ?

[Burgerman]

Correct.

Theres many ways to do this.
Many ways to connect, charge, with or without BMS, different costs, etc.

All will work. The one that will work best depends on a bunch of stuff and what you know and understand.

Headways are, 10Ah, 12Ah, 15Ah and 10C cells. So you need 8. Or 16...
The Hobby king packs are 8.5Ah and 30C cells are FOUR cells in one. So you need 2. Or 4...

Both can be used with a BMS, or with a hobby charger. The hobby ones can make a LOT more amps. You may not need that. But it cannot hurt.

All will need connecting cables, and if a BMS is used then even more cables but simple charger.

[Burgerman]

http://www.hobbyking.co.uk/hobbyking/st ... _bag_.html

From battery to easier connector...

http://www.hobbyking.co.uk/hobbyking/st ... ctor_.html

Lets you connect 4 hobby batteries to the charger in parallel and charge all 4 at the same time.

http://www.hobbyking.co.uk/hobbyking/st ... ouse_.html

Lets you connect 2 packs in parallel for 12V and 16.8Ah...

http://www.ebay.co.uk/itm/Deans-T-Plug- ... XQDnpTbLUI

Lets you connect those in series, so now 24V.

Then you need a deans to Anderson connector...

So use this, http://www.ebay.co.uk/itm/Logic-RC-Char ... Swj0NUf5YA

And crimp the 4mm round pins into the Anderson. Then zero soldering.

Of course it mean thinner than ideal cables, lots of connectors!!!
But its easy.

Personally I like to use a bit of cable with my connectors. I would solder everything, and use 6mm2 cable, and change the connectors on the batteries to XT60's.

You realise its easier to fit a complete lithium battery system?

[expresso]

whow - thats all the parts i will need ?

looks more complicated - but i guess as i do it - i see it will fall into place - - if i do this setup - i would need the other hobby charger - and charge this add on with that charger only - ?

Deans T plug - i would need Two ?

do i also need two Logic RC charge lead 4mm ?

most of those links are from UK - i have to find them here in states - and the prices are different from hobby king in the states - not too much different -

when all done - i then need a cable going from the battery to the SB 50 connector on my chair - which i guess i have to make ? or can i buy it made from hobbyking also ?

in the end this is going to cost easy over $600 - i hope i can get it done and it works - after that - i will save those links - and like you said - read a little bit more also -

with the ready made pack from EVA - that has the built in BMS - for some reason i like that - its easy - but if the BMS gave me issues if i got that one - can it be removed and then just use the Cells inside with out the BMS - ?

untimally - i want what ever i do to work - if it means i spend a little more with the parts - and as long as i can get help here after i buy the parts - i do it - i want to have this done by the summer - because i wont even know how far i can go with this added till i use the chair in june on the long trips -

thanks burgerman - i was getting disappointed - not in you or the forum - just me that i am having a hard time figuring this all out - and understanding what is so easy to almost everyone else here

worst case - if i really have to solder - how hard can it be - i just have to buy every little part - so i rather do with out solder if i can - but if i have to - and i hate having to buy another charger - i have so many dumb ones and smart ones - and now this hobby charger which i have to learn to use -

how many more miles you think i can get out of this ADD on - i can get a good 12 to 15 miles easy with the Lead alone - when i add this or any other pack on - what can i expect ? more or less -

[Burgerman]

Soldering cables, easy if you have done plenty before. Very hard to do right if not. So best left to an expert.

You COULD do it how I showed and it would be all plug and play. But too many connections, and quite thin cables mean it may not be reliable. And you would only be safe charging at 20A with the 40A hobby charger. Thats plenty though.

Also I dont like those T Deans type connectors. I would use something else. Like the yellow XT60 or 90 connectors. Theres a 1000 options. But Ideally you would make 1 lead, with a 50A fuse, and an anderson on one end. Use 6 square MM cable, and four sets of 5.5MM bullet connectors to fit the battery.

Then make up a similar charge lead with 4x 5.5mm bullet connectors, and two quality 4mm charger connectors. Then you can charge at 40A and go from empty to full in about 20 mins. Or do them individually.

You need to understand what is happening though. And how it all works. To not do so means innevitable problems!

[Burgerman]

how many more miles you think i can get out of this ADD on - i can get a good 12 to 15 miles easy with the Lead alone - when i add this or any other pack on - what can i expect ? more or less -

You get to USE about 38 to 42Ah from a 73Ah gel at very best. Before it stops completely.
So that means approx 40Ah takes you 12 to 15 miles. Call it 13.5...

Thats 2.96Ah per mile.

With a lithium battery you get to use ALL of the Ah it holds. So a 16Ah Add on means 5.4 miles extra, so 18.9 miles.
With a 20Ah add-on you will get 20.2 miles. In fact you will get a bit more than these figures suggest because you also win because of the reduction in peukert affect on the lead battery. Meaning its likely to be closer to 21 and 23 miles in reality.

Provided the lead is still healthy. Lead screws up and deteriorates fast.

[expresso]

i never soldered before - so i would have to buy all that stuff and who knows if end up doing that correctly -

you know all this stuff and have much more knowledge experience doing it - with your hobby background

you are right - alot of plugs to connect and not the ideal way - i dont mind charging at 20A and take 40 mins since thats great -

you know i am thinking maybe this may be the best for me to try for the first time

http://www.evassemble.com/index.php?mai ... ucts_id=56

all i would need is two cables to make - - one from the batter to my cable on the chair - and the other from the batter to plug in to charger at end of day and charge all at once together at 28.8 V with the 20A charger i have already -

i know the BMS thing is not the best to have and it may give me issues or cut off during use - but as long as the chair wont stop since it will have the chair Lead batteries to keep it going - all depending how deep i drained them both -

for the chair to stop - the ADD on would have to cut off - and the chair batteries would have to be so dead that it wont move the chair either way - ? thats correct ?

if so - just to save myself a big headache and dozens of connections - cables - adapters - i may just try this option for my very first time - if i can see the advantages and if it does really work enough to get me thru the day with out charging -

i be fine - then charge when i get home - with 20A - dosnt take long even when dead all the way - 3 hours about - maybe 3 and half with the Add on - before getting to Green -

i appreciate all your help burgerman for sure - your trying your best to make it as simple as possible for me - and even then i have tons of more questions

i have a few other friends who are interested and know even less than i do - they are waiting on me and want to see how it works for me before deciding if its good for them also - but they are looking for the same thing as me - plug and play type of add on - and this one is the only one i can find that is as close to that as can be -

it all comes down to this built in BMS in there - worse case - i can remove it later on ? or i end up loosing out and learned a lesson -

[expresso]

how big a fuse would i need if my 30A blew at some point -

60A - 70A fuse ? and the wire would have to be redone - its 10 gauge now - if the fuse blew - how low do i need to go - 8 gauge or lower ?

[shirley_hkg]

Expresso, thanks for asking, so here we go.

1, determine the size and shape of your add-on battery pack.

2, choose the suitable screw on type LiFePO4 cell, cylindricle / rectanglar block.



3, buy cells in multiple of 8.



4, I help to get you a suitable 3.65/2.5 BMS.



5, guild you to get it done here, step by step.



If you are choosing 38120 cells AND still worrying if you could do it , order 8 pieces first, together with bus bar, plastic holder.




Assemble in a layer of 8.

I can see that you don't have to use solder at all. ---- DONE. ----

Later on, if want more amps, simply purchase another 8 cells . Put it on the existing one , and to form just another layer on top of it. Screw on the bus bars. That's it.

NO MORE WIRING IS NEEDED , NO MATTER HOW MANY LAYER YOU WANT TO ADD. SIMPLY SCREW ON BUS BARS.

[Burgerman]

I think the best thing is to let him sit and think a few days. Information overload!!!

[flagman1776]

The way EVAssemble sells the cells is like a 'kit'. The cells come with METRIC phillips head stainless screws.
(HINT: Be sure to check your order number. The "S" after the 38120 S, 38140 S means the screw terminal unit. The 38120, 38140 without is a solder on cell.)
EVAssemble includes the correct orange building blocks & buss bars for the cells you buy.