PINNED - Lithium battery conversion/info

[JoeP]

You cant JUST crimp most Anderson 50 connectors as the metal is too thin. The exception are the ones designed for smaller cables as they have heavy thicker walls and can be securely crimped with a hydraulic crimper.

Great info. Much appreciated!

[shirley_hkg]

Line them up to a 14P8S rated 24V 210AH for testing.

Found only one bad among 112 cells, and get replaced.

After balancing, 200 AH were released on the first discharge, which was stopped at cell voltage @3.0X volt. Don't want to go too low.

Cells are good and capacity seems up to standard.

Together with Nandol's 190 ah pack , that is over 400ah here , and it is a BOMB.

[expresso]

nice - looks huge !!! -

[JoeP]

I like those custom CNC cut copper busbars.

Question: Headway's busbars are nickel plated copper, presumably to prevent oxidation. Will you are custom bare copper busbars eventually oxidize enough to interfere with electrical connectivity?

[Irving]

I like those custom CNC cut copper busbars.

Question: Headway's busbars are nickel plated copper, presumably to prevent oxidation. Will you are custom bare copper busbars eventually oxidize enough to interfere with electrical connectivity?

AFAIK copper doesn't oxidise in air unless heated to >300degC. It does react with weak sulfuric acids such as 'acid rain' with a greenish patina of copper sulfate. Freshly cleaned copper will dull when handled as the surface traps 'dirt' ions, but these polish off quite easily.

[Burgerman]

Well I hate to disagree, but as an ex plumber (my dads firm did heating and bathrooms etc) every old copper water pipe is extremely oxidised. And a pig to clean up. And if its more than a week after cleaning with steel wool to fresh metal, it wont solder at least not properly no matter how dry its kept.

EG All of this copper has never been to anything near 300 degrees. Yet its surface doesn't conduct, and you cannot solder it until you use steel wool or similar and remove the oxidation. http://l7.alamy.com/zooms/06a9e08101bf4 ... cp2ncy.jpg

Even NEW copper tube requires abrasive cleaning for a GOOD safe soldered joints. It looks like this after a couple of weeks only. http://1iykqqazokj1xthmsh7rzxle.wpengin ... photo9.jpg

Really old copper tube, even if kept in a store and never sees water, goes black and eventually green. Polished copper loses its shine in a day, and gets darker day after day.

DE -Oxidised copper looks like this. But only for about 30 mins... http://dintaimetal.com/uploads/C12200%2 ... copper.jpg

[Irving]

BM, I stand corrected. Copper, like aluminium, does develop a passivation layer of oxide that dulls the surface and reduces/prevents further oxidation, though it doesn't stop other corrosion such as the dark brown or green patinas from copper sulphides or carbonates. Pure copper exhibits passivation fairly quickly. Copper tube, made from a so-called 'de-oxidised' copper/phosphorous alloy (typically >99.5% copper) passivates much slower, over several days, unless the local atmosphere causes sulfation/carbonation sooner.

The passivation layer is CuO. and relatively soft and only a few angstroms thick. Hard oxidation, Cu2O, requires the higher temperature I cited before, and is much thicker/harder to remove.

Copper, like aluminium, can be anodised and can also be 'coloured' with wipe on/wipe off dyes/pastes.

[Burgerman]

Its this amongst other things (physical strength) that makes me dislike home crimps...They oxidise which doesn't conduct, and can be pulled out... You cannot get airtight secure crimps on larger sizes at home. And you cannot but adequate strength terminals.

[JoeP]

Both you guys are a font of information.
I used to wonder why my electricians screwed and bolted their copper electrical connections so darned hard (never bothered to ask).
I'm thinking that the compression probably act as a physical barrier to any surface oxidation.
But one does not dare apply very much torque attaching a busbar to a Headway cell.
I'm wondering if there might be the possibility of connectivity issues in the future. Just wondering.

[Burgerman]

Thats why the headway ones are copper and plated in something I suppose.

[JoeP]

Hey Shirley,
Read this article on oxidation of copper busbars: http://blog.prv-engineering.co.uk/why-a ... rs-plated/
You may want to haul those beautiful busbars over to your local electroplater.
Should be inexpensive.
Joe P

[shirley_hkg]

OK. Will play more attention to exclude weather erosion when packing it .

The bus bar has a 12 mm square cross section, and there are 6 bars in every paths. There will be much left to use, even heavily eroded.

Nevertheless, when I inspected my 5 years old A123 pouch pack, which uses copper pipes as bars, I didn't see they are severely damaged... Hope they will last a decade more.

[Burgerman]

Its not so much the look of it, or the resistance along the length. Its the increase in resistance at the bolts over time as the oxides build. Same thing with crimps. If you can guarantee they are airtight then all good! Otherwise they get worse over time.

[JoeP]

Its not so much the look of it, or the resistance along the length. Its the increase in resistance at the bolts over time as the oxides build. Same thing with crimps. If you can guarantee they are airtight then all good! Otherwise they get worse over time.

I think that's right BM.
Like Shirley I don't like "the look" of ship lapped busbars. Those straight runs of CNC busbars are a lot more elegant.
I figure if you're going to build a Rolls-Royce battery you might as well go for Rolls-Royce busbars. But I think I'd bring them to the electroplater to have them plated. Just one extra step involved but probably not much expense.

[Burgerman]

Zinc plate at home its super easy.

[JoeP]

What's the recipe?

[Burgerman]

An OTT kit... http://gaterosplating.co.uk/Zinc-Plating-kit.php

Or electrolytic application of zinc by sticking clean steel or copper etc parts in a zinc salt solution and applying an electric current... You can buy the solution on ebay etc. http://www.ebay.co.uk/itm/Zinc-plating- ... SwIgNXmKhL

[JoeP]

An OTT kit... http://gaterosplating.co.uk/Zinc-Plating-kit.php

Or electrolytic application of zinc by sticking clean steel or copper etc parts in a zinc salt solution and applying an electric current... You can buy the solution on ebay etc. http://www.ebay.co.uk/itm/Zinc-plating- ... SwIgNXmKhL

Very cool!

[LR8O]

very confusing reading things here with all these acronyms etc, if i wanted to just replace the 2 x 50ah lead batteries in the same space area ish, what realistically ah wise lithium would i be able to achieve? would i be able to double the range and power? or would i have to build something really big to achieve that, maybe someone could do a video tutorial that i could follow for such building advice, i was hoping to build a battery a similar size that of the area the 2 lead acid batteries took up so i dont even know if its possible to do and if so in that space it would be less powerful etc so not worth it? also the charging thing has me a bit worried charging up leaving for weeks? then charging up again or something, then when built being careful not to charge too much and not let them get too low, it seems more hassle??

[Burgerman]

There are no simple yes no answers. It may be possible to increase range to double. Its easy to do with grp 24 sized 70Ah lead, as everything fits. Its less simple with smaller batteries but can be done. You must read and understand. So that you know what will fit, and why, and how to connect, how to charge and why.

Dont fixate on Ah. Each LITHIUM Ah takes you further than each Lead Ah...

This is 120Ah lithium. To replace 68Ah lithium It takes it 3 to 4 times further... viewtopic.php?f=2&t=5380&start=260

[LR8O]

ok so the first step really is to see how much room i have to play with ?

[Burgerman]

Yes. To the mm. Then read lots... Scooters are easier on batteries. So lower C rate prismatic may be ok and be easier to fit as long as capacity and measurements work out.

[LR8O]

ok ill get measuring, what do you mean by lower C rate prismatic mean? or is that just going to be 1 of many many questions

[shirley_hkg]

[shirley_hkg]

[Burgerman]

That saves a few £ at the expense of no PC connectivity or control or graphing, apart from doing firmware, and far less programmability and settings options. Its a dumbed down version for amateur hobbyists. It also has lower balance current capability which matters for us, and lower discharge current capability and cannot do regenerative discharge. Its a very 'cut down' cheap option lacking many important details.

It also cannot do balance port only 3A charge/balance which is useful for charging other stuff. So its OK for a hobbyist flying planes on a Sunday using the built in 'presets'. Or a few basic setting options. Not very good for us at all, and is much like most cheap hobby chargers in this way. I took a look at one to use in my van. And returned it. You save a little, lose a great deal of the 'hidden' stuff that makes the PL8v2 so good. Its like the difference between painting a car in the spray shop, or using a brush...

[ronduino]

ok ill get measuring, what do you mean by lower C rate prismatic mean? or is that just going to be 1 of many many questions

Prismatic refers to the configuration of the cells in a battery.

C rate refers to the charge/discharge rating of the battery.

[Burgerman]

Prismatics are rectangular. But lower C rated usually. Yes one of thousands! EG Winston, CALB, etc. http://www.evassemble.com/index.php?mai ... ex&cPath=2

[ex-Gooserider]

Hi ex-Goowsrider,

I used to build houses and I've always been interested in 'best practices'. Somewhere I ran across your comments about military spec & crimping and that stuck in my head. I also used to be something of a tool junkie, but nowadays I'm lucky to be able to use a can opener.

In know its no Thomas & Betts, but would Powerwerx's $89.99 Hand Held Crimper qualify as a good crimper for SB50s? https://powerwerx.com/anderson-sb-connectors-sb50-50amp

JoeP

I use the PowerWerx crimper on the 15/30/45 size Andersons. I have a hydraulic unit I use on the SB-50 / PP-75 size, even though I also have the dies for the SB-50 pins as part of the crimper kit. PowerWerx CLAIMS that their crimper is approved by Anderson for use on those pins,

The Anderson documentation on assembly says to crimp OR solder, with soldering recommended for solid or minimal stranding wire (i.e. house-wiring style, as opposed to the marine or welding cable that we use) They don't mention the PowerWerx crimper, but the description of the manual crimper style is consistent with the PowerWerx unit...

What is interesting is that the hydraulic units that most of us are using on the SB-50's do a hexagonal crimp that basically squeezes the wire all the way around. However the description of the Anderson recommended tools are ALL for 'indentation' style where they crimp by denting the pin barrel rather than squeezing it, which I suspect might be more structurally sound. They also call out the use of a 'reducer sleeve' if using smaller than AWG-6 / 10mm^2 wire, AND cable clamps (note what I said earlier about strain relief, so that stress is NOT placed directly on the crimp...)

I currently crimp and solder the SB-50's but crimp only on the smaller sizes, and most other crimps. I may experiment with crimping only on my next builds...

ex-Gooserider

[Burgerman]

SB50s... You crimp them, and I will pull them out. Same with all the larger ring terminals etc you get nowadays.

Also dip one in salt water a couple of times and watch the cable and the crimped barrel corrode/oxidise in a week.

The only SB50 that is close to being adequate with a crimp alone are the ones with a small cable entry size. They have 2mm copper wall thickness. Those are the only ones with enough metal in them. Designed for 6sqmm or a fraction bigger cable. If drilled they take 10sqmm and still crimp adequately. They have a solid thick wall to the barrel, it requires a good hydraulic crimp and some strength. Those are air tight, and trying to pull the cable out results in a snapped wire. Those do not need soldering.

But the common ones, like all the ebay ones, with 16sqmm sized barrels can be crushed way too easily just under your foot. Those are too flimsy and soft to ever get adequate strength or airtight joints. I don't care what you crimp with, I can easily yank them out. And they may work initially but after a year or two oxides will say otherwise. They solder fine. They solder even easier if you crimp first.