PINNED - Lithium battery conversion/info

[expresso]

MK

[expresso]

tested better than expected - finished 88.5ah discharged to 2.9v - from 3.6v -

[Burgerman]

So realistically they are 90Ah cells fully discharged. Thats not bad for real Ah rather than chinese smaller marketing Ah!

Also remember you would get a little more if discharged at say .5C as they warm up and perform better. So I would not worry about those. A solid 180Ah pack with 16 cells. For 54 dollars a cell.

If you compared to lead MK Ah they are already about the same.
MK GRP 24 are 73.6Ah at the 20 hour rate. But sadly in the real world we go 7 to 8 mph. So do 14 to 16 miles and run out of fuel in almost exactly 2 hours after setting off! And thats the 2 hour rate. And that means we get just 35Ah to 40Ah from them before we grind to a halt!

So GRP24 accessible only 40Ah. We will ignore the 7 times shorter lifespan.
For how much? 519 a set. Plus shipping that we will ignore. https://www.phc-online.com/GRP24_Batter ... -24-ft.htm
Thats 12.9Ah per dollar.

LITHIUM: 8X cells, 54 dollars each for the 24V 100Ah (90Ah usable) is 432 dollars! Plus around 120 fedex air shipping. So 552 dollars delivered.
Thats 6.13 dollars per USABLE Ah. HALF the cost per Ah.
Or 552 compared to leads 519 dollars, but with 2.5x the range.
But you can fit 16! So you can fit 5x the stock range. Which is the whole point!!!

I cant afford lead. These figures ignore the 10 to 12 year service life.

[expresso]

so far i feel good all around with these cells and the seller has been great dealing with the return damaged cells - so i will when this is over and ready to get another replacement - considering get 16 now since i know they are good and fit -

can take my time testing and build it in the winter - no rush - try to improve each time - cant beat the cost - size and Ah Cap.

i was told - honesty they would give me anywhere between 92ah and 96ah - thats following there discharge volts - and if i did - i would have gotten the stated specs - so happy i got more than expected - 85ah was what i expected

[Gnomatic]

I have the 75Ah version of these cells from the same seller. Very consistent, all measured ~66Ah to 2.9v. I was a bit more conservative on the Ah to fit, as I am having a bespoke 1.5mm thick sheet metal box made to house them. Which will easily fit in the footprint of my lead bricks, insulation included.

[expresso]

thats the best bet all around for high Ah and fully sealed - if you have the room - thats the way to go - easy to work with that size

how tall are those ? 195mm ?

[Gnomatic]

Yes 195mm tall. Room to spare in all directions. Which is what I wanted.

[expresso]

i doubled checked mines - they are spec to be 202mm - i checked on inches and comes to 8 inchs - should give me room for wiring and end up the same as the MK at 9.5 inches hopefully

you have tons of room to seal those nicely and never worry

its too bad those 200ah Cells cost more - the ones i found - would be easier with 8 Cells to build etc, but they cost double the ones i found - not worth it -

this way i can get 2 spares also - in case its ever needed - down the line - would be wise to get 2 extra ? i hate to have extra cells just sit around though -

[Burgerman]

https://www.rj-lithium.com/sale-1154646 ... cells.html

the 92Ah ones here seem to be them.

[terry2]

more

Looking great
The cat is saying "I did all this, but do I get credit for it? No)

Question. Is it good to use the PL8 to run the cells down to 3.0v? and if so why?

Is it to see how much AH you put back?

[Burgerman]

No its to see how much you take out!

If you charge to a safe 3.600V, discharge to a safe 2.90V then you are measuring around 95% to 97% of the cells ACTUAL capacity.
Rather than the claimed capacity which can be because the chinese exadurate, or because the cells are wearing out or damaged by under or over charge/discharge in volts or Amps.

[terry2]

No its to see how much you take out!

If you charge to a safe 3.600V, discharge to a safe 2.90V then you are measuring around 95% to 97% of the cells ACTUAL capacity.
Rather than the claimed capacity which can be because the chinese exadurate, or because the cells are wearing out or damaged by under or over charge/discharge in volts or Amps.

Thank you.
Full of knowledge as normal

I am trying to run mine down by going out and about.
But it's going to take ages until the warm weather comes.

I may use the PL8 if it's safe to do so.

[Scooterman]

I am trying to run mine down by going out and about.
But it's going to take ages until the warm weather comes.

I may use the PL8 if it's safe to do so.

The weather is crap at the moment. I went out on the scooter yesterday but only did about 10-11miles.
I've decided i need to fit a small polycarbonate wind screen. I've been looking at some 1mm lexan A4 size which I'm hoping i might be able to velcro on so removable in hot weather.[/url]

[Burgerman]

Get a good motorcycle helmet. Warm, quiet, and less likely to be killed so badly. And scare a few old ladies and car drivers...

[expresso]

https://www.rj-lithium.com/sale-11546469-lifepo4-3-2-lifep04-battery-3-2-volt-battery-lifepo4-battery-cells.html

the 92Ah ones here seem to be them.

yes i seen those also before - i never asked for price etc, would be curious to find out - i feel good with my Seller now so dont think i be switching - also you never know - i like to take 10ah off the top of what ever they advertise as a way to know the true Cap. and so far it seems to be working that way more or less

i was told the Cells were going to be at Min. 92 - 96ah - and comes out to be pretty much true - in my mind - if getting a Cell advertised as 92ah - then i would expect about 80ah Cap at least - so i went with the 100ah - pretty much for the size and cost - and its 100ah - so i get a decent 90ah out of them - very very close to 90ah - i am fine with the results - the quality and the seller so far -

now i have to pack them up today - BM ask them about those Cells - see what they say - i will shot them an email also - curious to see if we get the same results back -

[expresso]

@Terry - its safe to use the PL8 for a full discharge test to find out the Cap of your pack - BUT - its very slow on a large pack - i done it once on my first 105ah pack Took Days nights non stop and to be honest - i even forget what the Voltage was that i had too watch out for

never had an issue anyway - and i since added 45ah more - in your case you have 150ah ? its too slow - can be done if you want to leave it for a few days -

i will have to get a dump inverter or something like that - then can discharge it at 20A and still takes a day - but thats not bad - use it till close enough to the end - then stop and finish up with the pl8 so it will stop at 2.9v can have an idea of Cap. and the Voltage of the pack at 2.9v

thats what i will do when or if i do the next one - 200ah is alot to use a pl8 - i will do each cell when i do mines just to know - with the pl8

since i am in no rush - one cell at a time - give it two days a cell - to charge - discharge and recharge once - i be done by xmas

[Scooterman]

Get a good motorcycle helmet. Warm, quiet, and less likely to be killed so badly. And scare a few old ladies and car drivers...

Hmmm thank you, I think? And may the force be with you BM.

Btw I was going to ask you being an ex-motorcyle man how high to position the top of the screen. But I did some googling and the consensus seems to be just below eye level. So I've decided I'll have a go, I'm quite looking forward to fitting one I hope it doesn't blow-off when going down the road or decapitiate me if I crash . Maybe I should glue some split rubber hose along the top edge?

[Burgerman]

On a bike the whole fairing/seating and screen work to throw a bubble of air over your head and down your back for reasons of aerodynamics. At 150 to 200 mph its important. It low enough that you can sit up and see over it at traffic speeds, and not really designed to look through clearly. So its top edge is eye height or a little less. At high speed you get a few inches lower and it stops the 180mph airflow from trying to tear your head off!

Doesent really apply at scooter speeds...

[Burgerman]

At low speeds you are not tucked behind...

[woodygb]

Get a good motorcycle helmet. Warm, quiet, and less likely to be killed so badly. And scare a few old ladies and car drivers...

Hmmm thank you, I think? And may the force be with you BM.

Btw I was going to ask you being an ex-motorcyle man how high to position the top of the screen. But I did some googling and the consensus seems to be just below eye level. So I've decided I'll have a go, I'm quite looking forward to fitting one I hope it doesn't blow-off when going down the road or decapitiate me if I crash . Maybe I should glue some split rubber hose along the top edge?

https://www.amazon.co.uk/Universal-Moto ... 3RSS2D1CGS

Attaches via your mirror mounts ( M8 )

[terry2]

Just had these come from the battery guy(I never asked or paid for them)
They are 2.2mm thick, but the middle is a bit bendable .
I have emailed him to see what he wants done with them.

[Burgerman]

Bin.

[terry2]

Bin.

He may want me to send them back.
They are thin strips of copper plate. Solid at the ends and flexible in the middle.

[Burgerman]

How flexible? Like a cable?

[Gnomatic]

Get a good motorcycle helmet. Warm, quiet, and less likely to be killed so badly. And scare a few old ladies and car drivers...

That is a badass helmet!

[Burgerman]

[Burgerman]

[Scooterman]

You've got nice hands Terry . Mine are filthy and cut to pieces



Thank you Woody, but I saw your post too late . What you linked to looks perfect!!! .

I ordered this https://www.ebay.co.uk/itm/1-mm-A4-Lexa ... 2749.l2649 this morning. I'll give it a go, but if it doesn't work I won't have lost much and will order that screen.

[Gnomatic]

I'd go with the Predator LOL.

[expresso]

after making wire cables for my 80ah pack - the charge graphs are perfect - cant get any better - they were not bad before -

one pic is before - the perfect line is today after - i now know what to do if it happens again - since i added lock washers to the only 4 that were a bit stripped with larger screw - if i have to redo it again - i will add all lock washers with a touch of locktite and all get larger 10mm screws - change the one wire cable thats not bent - and that should be it -

very happy with these 80ah Cells so far