PINNED - Lithium battery conversion/info

[Scooterman]

The new cells have arrived, finally!

They're to go in my Salsa R2 powerchair. They're a tad long to fitted in the battery comp' but I knew that and will need to make a new battery back plate out but that's easy enough, it's just a rectangle with two slightly bent flanges to gain a few more millimeters.

They were extremely well packaged, although one box looks like it was opened to inspect the contents?

I won't be using the busbars but they're not bad, quite thin and with a bit of flex. AND rather than screws they've supplied M6 studs flange locknuts and washers.

I've only unpacked and inspected one cell at the moment.

It looks brand new, the only caveat is the terminals, although the threads seem good.

After purchase I notice one or two reviews of the cells posted on the site and the buyers mentioned marks on the terminals, some even uploaded photos. I don't whether that means they're old cells, or the company/factory tests the cells, there's a 'tested passed' sticker on the cells and the milli-ohm rating. I guess the 3.29v means the voltage they were stored at prior to shipping? Whether they're tested NEW cells or tested OLD cells, I don't know, but if they were old I would have expected to see more marks on the outside of the cells. I check out the others later.

Album url: https://postimg.cc/gallery/375z6xile/

[Burgerman]

The cells are new. But for reasons that baffle me are usually supplied with no holes or threads to the people that distribute them. So they manually drill and tap them. Some do it extremely well. Som like yours look like a 10 year old has butchered them. I suspect you should examine the threads very carefilly. And debur the edge with a countersing tool very carefully. Some are not even drilled centrally in your pic.

[Scooterman]

Well spotted, is that the reason!

You’re dead right on opening the rest some holes are quite way off centre and have a raised tapping burr. I taken off the worse of the burr just to test. And if test okay will properly address the issue during install. The threads seem okay though, and overall (pre-test anyway) I happy with the cells and the packaging.

Do you think the untapped cells the seller buys were originally intended to be welded terminals in say a massive commercial solar bank or electric vehicle?

[Burgerman]

Not sure you could weld them easily being alloy. They would melt the battery.

[shirley_hkg]

I had great admiration to your affection for your child.

Meanwhile , I always felt sad to learn the other.

second, because being 74 years old I have to plan for when I'm no longer around.

@LORBBINS, This genuine 9-channel charger may be more reliable and still easy to operate.
It can auto start as it sees a battery. Can also discharge @2.7A
May set all 32 memories with SAME volt & amp for foolproof .

UN-A9 can do 8A max (advise to add 1.00-1.25m㎡ balance leads from pcb direct, the 2.54XH plug is too weak)


In view of RACHI's low consumption , it can put back 60---70Ah overnight .

Powered from 12V @HKD $400.

The BMS I quoted still need quite some corrections .

[terry2]

Does anyone know where I can buy a M6 x 1.0 STI finishing tap?

All kits come with a starter tap. But not a finisher tap.

[Burgerman]

Any decent tool shop. Buy Dormer HSS. Bottoming tap, end tap, finishing tap. Dont buy cheap taps...

Or a relatively throwaway but half decent tap if you only intend doing a few threads. https://www.amazon.co.uk/Volkel-5mm-0-8 ... -1-catcorr

If you want more 'bottom' than this, take the 3rd tap, grind the last 2 mm off the end as a 4th tap. But remember that the bottom of the hole is drill bit shaped! As in has a point.

[terry2]

Any decent tool shop. Buy Dormer HSS. Bottoming tap, end tap, finishing tap. Dont buy cheap taps...

Or a relatively throwaway but half decent tap if you only intend doing a few threads. https://www.amazon.co.uk/Volkel-5mm-0-8 ... -1-catcorr

If you want more 'bottom' than this, take the 3rd tap, grind the last 2 mm off the end as a 4th tap. But remember that the bottom of the hole is drill bit shaped! As in has a point.

Found an STI tap https://www.amazon.co.uk/PowerCoil-3520 ... B00MWU058I

[Irving]

Any decent tool shop. Buy Dormer HSS. Bottoming tap, end tap, finishing tap. Dont buy cheap taps...

Or a relatively throwaway but half decent tap if you only intend doing a few threads. https://www.amazon.co.uk/Volkel-5mm-0-8 ... -1-catcorr

If you want more 'bottom' than this, take the 3rd tap, grind the last 2 mm off the end as a 4th tap. But remember that the bottom of the hole is drill bit shaped! As in has a point.

Found an STI tap https://www.amazon.co.uk/PowerCoil-3520 ... B00MWU058I

DON'T BUY THIS - you will regret it

Its not a standard tap, but one for use with Helicoil & similar wire inserts (thread repairing). It cuts a wider thread than a standard one.

[terry2]

Any decent tool shop. Buy Dormer HSS. Bottoming tap, end tap, finishing tap. Dont buy cheap taps...

Or a relatively throwaway but half decent tap if you only intend doing a few threads. https://www.amazon.co.uk/Volkel-5mm-0-8 ... -1-catcorr

If you want more 'bottom' than this, take the 3rd tap, grind the last 2 mm off the end as a 4th tap. But remember that the bottom of the hole is drill bit shaped! As in has a point.

Found an STI tap https://www.amazon.co.uk/PowerCoil-3520 ... B00MWU058I

DON'T BUY THIS - you will regret it

Its not a standard tap, but one for use with Helicoil & similar wire inserts (thread repairing). It cuts a wider thread than a standard one.

I should of put more info.
The STI taps are for helicoil.
I am fixing a 6mm thread.
My mistake

I have taken the cells out of my Puma 40S and will get them ready for storage.

[Irving]

Found an STI tap https://www.amazon.co.uk/PowerCoil-3520 ... B00MWU058I

DON'T BUY THIS - you will regret it

Its not a standard tap, but one for use with Helicoil & similar wire inserts (thread repairing). It cuts a wider thread than a standard one.

I should of put more info.
The STI taps are for helicoil.
I am fixing a 6mm thread.
My mistake

I have taken the cells out of my Puma 40S and will get them ready for storage.

Phew!

Well there's always the danger someone else less knowledgeable would take it as a recommendation...

[terry2]

Phew!

Well there's always the danger someone else less knowledgeable would take it as a recommendation...

Very true.

[Scooterman]

I've known about helicoil inserts for donkey's years but have never used one or seen one used. Millennials don't realise what life was like before the internet. I found this video, not that you obviously need one Terry. It was just for my benefit, and anyone else who might not have seen thread inserts fitted before.
youtu.be/56Q5k3VbHwA

Growing up in a small village there was bugger all engineering books in the local library, although a few Haynes manuals which were helpful to a degree.

[Scooterman]

New cells tested from 3.6v down to 3.15v

old 90Ah 2P8S



new 8S




For the depth of discharge both the 180s and 150s give about 88%, but the older 180s are a much nicer graph.

[stevelawiw]

Got a box of these today
https://uk.rs-online.com/web/p/products/6048272/

[Burgerman]

After a dozen cycles, they will all get closer like your older ones. As long as no bad connections.

Talking of helicoils. They make very strong threads in weak allow materials. As such when building race bike engines, that are going to be stripped down many times, I would helicoil all of the threads tapped into the head, block etc as a matter of course. Even on a brand new engine. The first time you get chance on the bench, do the lot! I did the same to the alloy V8 that was transplanted into my 4 cylinder ford... They are cheap in bulk. Its just a time thing. And if its your own time thats free.

I note that on his video that it screwed in loosely. If you use a quality tap, they fit quite firmly. Loctite is a good idea, but they are usually tight enough that its not essential. I used it anyway, and on dry clean threads. But once you fit a few you will think its dead easy. And look at all threads in soft materials suspitiously! I would be temptedto do all the cells...

[Scooterman]

After a dozen cycles, they will all get closer like your older ones. As long as no bad connections.

Cheers, thanks for that, fingers crossed.

Talking of helicoils. They make very strong threads in weak allow materials. As such when building race bike engines, that are going to be stripped down many times, I would helicoil all of the threads tapped into the head, block etc as a matter of course. Even on a brand new engine. The first time you get chance on the bench, do the lot! I did the same to the alloy V8 that was transplanted into my 4 cylinder ford... They are cheap in bulk. Its just a time thing. And if its your own time thats free.

I note that on his video that it screwed in loosely. If you use a quality tap, they fit quite firmly. Loctite is a good idea, but they are usually tight enough that its not essential. I used it anyway, and on dry clean threads. But once you fit a few you will think its dead easy. And look at all threads in soft materials suspitiously! I would be temptedto do all the cells...

Yes i can see what you say makes sense. While i was watching that helicoil video it gave me the idea that if only m4 cells are available in certain size they could be helicoiled m6. Best if someone has a pillar drill rather than hand drill

i plan to buy a pillar drill day one day

[shirley_hkg]

YOU forgot , that you might have very shallow terminals to work with. Could be too shallow at all.

[Burgerman]

If thats the case, you fit them in upside down, and use a dremel to cut the top off. With the tang.

[terry2]

If thats the case, you fit them in upside down, and use a dremel to cut the top off. With the tang.

That's why I bought a STI finishing tap. The hole is not very deep.

[Scooterman]

If thats the case, you fit them in upside down, and use a dremel to cut the top off. With the tang.

That's why I bought a STI finishing tap. The hole is not very deep.

No they’re not.

Do the thread inserts Come in different lengths or do you have to cut them to length?

[Irving]

Do the thread inserts Come in different lengths or do you have to cut them to length?

They come in different lengths starting at nominal diameter so for m6 that's 6, 9, 12 & 15mm or so. You need a minimum of 3 - 4 threads so tapping out m4x0.7 with say 6 threads depth would only just give 3 - 4 at m6. It could be quite marginal. Better just to helicoil at m4 to add strength.

[terry2]

I am only helicoiling one hole.

I have drilled an extra 1/4 inch deeper so the whole helicoil goes in.

[Burgerman]

I would do the lot, properly and very accurately right now while you have the chance.

[Scooterman]

Do the thread inserts Come in different lengths or do you have to cut them to length?

They come in different lengths starting at nominal diameter so for m6 that's 6, 9, 12 & 15mm or so. You need a minimum of 3 - 4 threads so tapping out m4x0.7 with say 6 threads depth would only just give 3 - 4 at m6. It could be quite marginal. Better just to helicoil at m4 to add strength.

Thanks irving, useful information

I would do the lot, properly and very accurately right now while you have the chance.

I agree, aluminium is crap at holding a thread. I think everytime you bolt and unbolt wears the thread.

[terry2]

I would do the lot, properly and very accurately right now while you have the chance.

I was thinking about doing that.

But the rest are ok. So I am gluing 6m X 16 mm Grub screws with hex ends in to them.
So should be ok.

My new chair battery bay is going to look empty with the cells in

[Burgerman]

Then you choose the wrong cells. The idea is to get as many Ah as can fit into the existing battery area. In order to get the advantages lithium can give you.

[Scooterman]

My new chair battery bay is going to look empty with the cells in

Is that cos it can take 2 x 105Ah lead acids?

[Burgerman]

Yes. It takes grp 27 ir 31 batts. Its a massive rear steer scooter. Theres no need to constrain yourself to grp24 sized lithium. So instead of 210Ah of lithium you can likely fit nearer 300Ah and have great longevity and massive range, at the same tme as saving 60 to 65 lb of weight. Because those 16 105Ah cells will be cold and shivering hiding in the corner...

[terry2]

Then you choose the wrong cells. The idea is to get as many Ah as can fit into the existing battery area. In order to get the advantages lithium can give you.

You forgot your thinking cap again
I had the cells before the chair

My new chair battery bay is going to look empty with the cells in

Is that cos it can take 2 x 105Ah lead acids?

It can take 120Ah and then some

It's a awesome chair, way better than the Puma 40S in everyway.