200Ah Pack

[expresso]

Although using bus cables are good in theory, your end result looks not good. I still prefer using bus bars as your first build. My pack uses bus bars too. They are brass (not copper), handmade (not flat). All mean bad. But the pack survives more than 2 years. The balance graphs seem getting better (I do not know why). I see your pack is built better than mine. If there would be problem, it would happen to my pack first and I would inform you

I agree with you - it dosnt look good with the cables in the way they ended up - i made a bad choice to use thick wire and those lugs are too big - i will reuse the same wire to connect them across - but i am really leaning on goin back to those buss bars - wire it up - screw it down tight lock nut and test it - i feel it will be fine also -

is there a chance it wont when in the chair or in use etc, - yes it can be but i will notice it right away during recharge and then can fix it if needed and worry about it only if it happens - i know the two cells wrapped together first as ONE Cell is not going to move - and the pack is wrapped decent enough also - dosnt move

once in the battery tray - all wiring down etc, - it will be wrapped again - given i have the space which i believe i will - i may go down this road and try the buss bars first - i dont have a chair to use it in yet anyway and have time to test it and redo it i really have to - using lock nuts - dont have to reglue anything - just unscrew - remove wiring and redo.

thanks for the input - i know not many will agree to use the buss bars and i understand why -

[Scooterman]

Expresso or anyone.

If cable is a tad to thick for lugs, you can always pull a few strands out so it's a snug fit in the lug. Don't cut away strands with side cutters, always pull strands out with pliers. It's easy with silicone cable and even with long cable runs the strands will still pull out. If not warm up the insulation with a hair drier.

But it's not so easy with PVC cable.

Also if I was to make copper links I'd do this...

[expresso]

thanks - theres no way to really try to fix my cables i made already - thats a done deal - will remove and just keep for who knows what or when i can even use them - or maybe can cut off the ends and reuse if i need a shorter cables - but they are short enough already -

i will follow what snaker suggested first since i have everything i need to just bolt it down and see - if that is not working out - then i will do what shirley suggested - i ordered new ring ends smaller size for 12 or 10 Awg and will make a very short wire - will try that first with no soldering involved -

i feel it will be OK with the buss bars i have already - once bolted down tight with lock nut - i dont see it moving - as long as the contact is flush enough which i will tighten it down very good - we shall see

[Scooterman]

i know not many will agree to use the buss bars and i understand why -

You gotta do your own thing expresso. Listen to what other people say but ultimately it's your own choice. If you're happier using bus bars use them. I'll be interested in how it works out for you

PS: When I connected my 16 cells with wire links I had something like 30 individual links, 60 lugs/crimps!

[LROBBINS]

If you do use buss bars you may want to tin them by fluxing and dipping in a bath of molten solder then shaking off the excess and using a straight blade to wipe smooth. Careful to not burn yourself, however.

[Scooterman]

If you do use buss bars you may want to tin them by fluxing and dipping in a bath of molten solder then shaking off the excess and using a straight blade to wipe smooth. Careful to not burn yourself, however.

Good idea

Also re copper links they don't have to be as thick as perhaps people might think? And thin allows more for more flex.

For E.G. 25mm wide by 0.5mm thick flat copper bar gives a CSA of 12.5mm2.

I'm not sure what that is in AWG, size 6 silicone cable?

[Burgerman]

The other way is also easy.

Electro plate them. They are only about 50mm long?
They will go in my electroplating jar! Then you can plate them with shiny nickel!

Copper coins, before, and after!
Or copper bus bars. Nickel works well, doesent oxydise or corrode. Easy to do in 3 mins. Clean, dip in, apply power (3V and 3A max), take out. Done! And its fun.

Copper coins, before, and after!

[expresso]

nice looks cool - but i wont be doing it - haha - i wonder if i can find a place to just have them done - most likely not - with out shipping them out or costing too much etc, -

i figure this - my first chair pack i did use the copper ring terminals - and its going fine 5 years later - i have replaced some years back when i had to change out one Cell - but only the ones i had to address - i didnt take it apart - so how bad can this be - we shall see - i did ask the seller if they had the same kind size etc, coated already but they didnt.

for some reason - all you ever get are copper buss bars - if its that bad - Why do they keep making them in copper

[Scooterman]

Cos copper is an excellent conductor and malleable.

Lead is probably a good conductor as well cos it’s a component of solder?

[Scooterman]

If you do use buss bars you may want to tin them by fluxing and dipping in a bath of molten solder then shaking off the excess and using a straight blade to wipe smooth. Careful to not burn yourself, however.

For a solder bath are chunky sticks of solder broken up and dropped in?

[terry2]

If you do use buss bars you may want to tin them by fluxing and dipping in a bath of molten solder then shaking off the excess and using a straight blade to wipe smooth. Careful to not burn yourself, however.

For a solder bath are chunky sticks of solder broken up and dropped in?

There is a picture of my Busbars on here some where....Oh yeh you said something about my hands

Copper and already tinned and flexible.

[Burgerman]

for some reason - all you ever get are copper buss bars - if its that bad - Why do they keep making them in copper

Same reason they keep fitting BMS.

Because its all common percieved knowledge. Everyone knows its true! Everyone that doesent get it, keeps on repeating it. All the 'experts' on youtube are a typical example. 99% of youtube is garbage. Like running your battery down fully before you charge it. And 101 other well known truths that are wrong. Theres usually some truth somewhere, but people are dumb. I read a website of a supposed battery manufacturer (bought in, own brand lead bricks made in china) with the same old discharge fully instructions... And total confusion between gel and AGM.

The thing is that copper IS a great conductor. But that isnt the problem we have. The actual level of conductance depends on many things, inc cross section etc. Not least length, too. So as long as its adequate, we could use aluminium (terrible conductor, but fine in battery terminals, power lines etc) or any other metal. If of adequate cross section. But thats where the truth part is. But it ignores the voltage potential between different metals like alloy batt posts and bare copper, 0.5V! And the subsequent electro chemical reactions and oxidation it causes etc. And theres LOADS of those joints with 16 cells... 32 pos, 32 neg! Its why I always say use tinned marine cable too. Although once soldered properly thats not an issue. Just goes all black were it isnt soldered over time! But crimped alone it IS a problem.

[Scooterman]

The electricity boards (now private companies) use aluminium cables. In the IEE wiring regs there's table for aluminium cores (as well as copper). Stating current carry capacity, voltage drop per metre, single phase or three phase, a single core, twin, 3/4 cores, blah blah...
And you can't use copper fitments or terminals. Not sure about brass though? Although they don't use brass much nowadays. From experience most of the nuts and bolts and terminals in electrical panels as I remember were cherodized steel (however you spell it?)

PS: I googled various metals and pure lead is a very poor conductor. That surprised me as I thought being a dense metal it would be an excellent conductor.

[Scooterman]

Oh yeh you said something about my hands

Wear your pink marigolds

[Scooterman]

https://www.ebay.co.uk/itm/Flat-Copper- ... 2296818531

Crimp/solder into tinned copper lugs? Being braided the crimp terminal will grip it better than fine stranded cable?

Just a suggestion....

[Burgerman]

You mean like these? If you plan on solderingit doesent need to grip at all.

I could easily pull those off. Just soft copper lugs. Thin walled. And in time they will still oxydise. They are crying out for a little solder! Even has a little hole to feed in solder.
Yet they are sold like this...

[Scooterman]

You mean like these? If you plan on solderingit doesent need to grip at all.

I could easily pull those off. Just soft copper lugs. Thin walled. And in time they will still oxydise. They are crying out for a little solder! Even has a little hole to feed in solder.
Yet they are sold like this...

I totally agree with you BM.

I have found the pre-made braided links but they tend to be quite expensive, especially if someone's hooking up 16 cells. Also the shortest length I've found is 6" which is a bit long. Even with chunky prismatics half that length would be plenty I would think...

[Burgerman]

Just buy the correct sized lugs. If you want to add 2 cables to each cable lug/ring terminal, get one with 2x the cross section of the cable.


So if your cells use M6 bolts, and you are using 6mm2 cable as I would, buy: 6.6mm hole, and 12sqmm (or bigger) so you can add an extra cable to each one. To daisy chain the extra cell. Crimp, then solder with a little turbo cigarette lighter. Theres loads of easy neat ways to do it.

[expresso]

i have the cables all made already - i have done that with the Charge connector and ADD on - so its using one lug for two jobs - i could have or should maybe have done that with 3 connectors in one larger ring size - the whole thing is the joining of the two cells together first -

i havnt decided yet but leaning on just using those buss bars i have and see how it works out -

[expresso]

based on this - if i went with cables again - would 12 awg be enough for connecting the two cells ?

in case i go down this road ?

thanks

[Burgerman]

Maybe just... 10 is better.

[expresso]

i have enough of both wiring 12 or 10 awg - waiting on the ring terminals to decide how it would work - i am still leaning on the buss bars which i may just do first and see - leaving the cables for a backup plan in case i dont like the cable loops - too large too many connectors rings on each post - i didnt make the studs too long to be sure it will fit in any chair with gr24 size battery.

if the ring terminals are small - they should be - maybe i can make a very short wire between both and not loop them - same size as the buss bars but with a wire - but it would be very very short wire -

[Burgerman]

A loop is better.

[expresso]

i will see when i get the ring terminals in - to make one small loop - one across - which looks fits better with the rest of the cables - or buss bars

[ex-Gooserider]

You mean like these? If you plan on solderingit doesent need to grip at all.

I could easily pull those off. Just soft copper lugs. Thin walled. And in time they will still oxydise. They are crying out for a little solder! Even has a little hole to feed in solder.
Yet they are sold like this...

Actually the hole is NOT intended for soldering, it is intended as an INSPECTION hole for QA purposes - if the cable was made properly one should be able to see the end strands of the cable in the hole.... If not then the bare cable was not sufficiently inserted before crimping....

No reason the hole can't be used for soldering if one chooses to, but that isn't what it's there for...

ex-Gooserider

[expresso]

i think i am going to do it with the buss bars - this works - just have to add the balance wires and thats it - i just did a test fit and looks much neater - once its locked down with lock nuts - the cells are not going to move

i just have to make another cable to join the two packs so the wire is on the inside - may have to use a thinner gauge

[shirley_hkg]

It's all over the ebike forums about copper-aluminium reaction.

Wish you luck, if you have aluminum cell terminals.

[Burgerman]

That .5V (500mV) aluminum/copper difference and the galvanic corrosion, as well as the affect of cell voltage reading error caused is important. As you shirley found out trying it yourself.

[Scooterman]

Why not do this espresso then you won't have that awkward tight link cable?

8 cells photo but same principle with 16

[shirley_hkg]

This is exactly what I 've suggested, using what he has already made.

Just solder thin wires for paralleling & balancing .

Then only one lug per batt terminal to cope with under-length stud.