PINNED - Lithium battery conversion/info

[expresso]

It was a speed/roadblock/gun incident and ended as a bail jumping thing... They dont like me.

i though you didnt like guns ?

[Burgerman]

I dont mind at all if I am the one holding it. But I wasn't!!! The cops were. They think speeding for a few hundred miles of deserted desert is a hanging offense over there!

[ex-Gooserider]

Another question - How good is the quality on the cells???

If I go with the 15Ah pack as discussed earlier, I will need 48 cells... If I do the proper balanced-pack construction, what are the odds of getting 48 cells that will all test as good?

I have noticed some of the other build reports where folks had a few cells that showed self discharge rates way different from the majority, and the advice was to consider those cells as bad, and not use them...

I don't want to order more cells than I need, but I also don't want to end up short if some turn out bad....

Is it a reasonably safe bet to just get 48 cells, or should I order extras? (If I do, I might get 56 cells so that if all do turn out to be good I have the conversion packs plus an 'add-on' or just a 'test-use' battery for bench use...)

Opinions?

BTW, in looking for quotes, I've found a couple of places that are less than Evassemble, including a vendor from Ali Baba that is about $200 less - Is there any reason to think that Evassemble will be significantly better for reliability / quality?

ex-Gooserider

[Gnomatic]

I dont mind at all if I am the one holding it. But I wasn't!!!

That was you on that episode of Cops wasn't it?!

[Burgerman]

Your download could not proceed because it would take you over the current free transfer allowance for your IP address.
To enhance this limit, you can register an account. This will not only give you ample extra transfer quota but also 50 GB of secure storage space in the cloud -

MEGA...

Cells? Pretty likely all good. Other vendor? No clue! Its china so anything is possible!
.

[Gnomatic]

expresso, if you need remote help with you PC, download TeamViewer. It allows someone else to remotely take control of your PC(or vice versa).

I use that program a lot to work on/fix a lot of PC's remotely.

[Burgerman]

expresso, if you need remote help with you PC, download TeamViewer. It allows someone else to remotely take control of your PC(or vice versa).

I suspect theres at least 3 or 4 people in it already!

[expresso]

When i did the full pack - i got 2 extra cells only to be safe just in case - i never needed to use them and still have them here -

but if you do plan on making a ADD ON also - might as well get enough to make both - this way you dont waste nothing -

[expresso]

expresso, if you need remote help with you PC, download TeamViewer. It allows someone else to remotely take control of your PC(or vice versa).

I use that program a lot to work on/fix a lot of PC's remotely.

thanks - i am not up to speed with you guys - but i get it done one way or another - i realize this isnt the section for this computer talk - so i will end it here -

if anything i post it in the other sections

[Gnomatic]

If I go with the 15Ah pack as discussed earlier, I will need 48 cells... If I do the proper balanced-pack construction, what are the odds of getting 48 cells that will all test as good?

I didn't order any extra cells, just the 56 needed for my pack.

Right now I'm halfway in topping off the cells, measuring their 60 day self discharge. At one end a couple cells so far needed as much as 185mAhrs put back into them, and at the other a couple cells that took in slightly less than 90mAhrs. Everything else is in between. Hope that is okay!

[Burgerman]

Yes. They vary in self discharge rates. Thats why you are measuring. So you can put groups together that add up to the same amount. That way you will be able to store a pack months with very little balance problems.

[LROBBINS]

Here's a link to a fairly step-by-step guide to doing what John suggests for Windows 10.

http://forum.notebookreview.com/threads/nbr-windows-10-clean-installation-guide.781178/

Obviously, you don't need to do everything exactly as he suggests. Aside from the initial installation instructions, most of this is also applicable to a Win10 that's already installed. There are also links in the comments at the end to some other useful things. For example, to this:

http://www.windowscentral.com/how-prevent-windows-10-requiring-password-when-resuming-sleep

[Burgerman]

http://forum.notebookreview.com/threads ... de.781178/

Thats a good start! And covers about the first 1/2 of what you need to do.


Win 10 should come in two versions. Two starting points. Two options.
1. Dummy mode with all icons and advertising/phone home and other dumbed down money maker garbage and no metro apps or crap browsers etc. And:
2. Serious user mode with all that crap removed/turned off, and configured to be usable and stop wasting 3 days of our time to get it like that...

Personally I have a version thats ready to deploy to any machine via macrium boot USB already done and configured. You may just need a driver or two for stuff it cant find. 2 weeks configuring, windows only. And then stored as a backup ready to go.

[expresso]

i will continue this in the laptop section i started - in Anything -

sorry i started this in the Wrong section -

viewtopic.php?f=5&t=6792

[Gnomatic]

Finished topping the cells off. Here's what they look like.

Headway 60 Day Static Discharge.xlsx.zip

(11.73 KiB) Downloaded 235 times

[Burgerman]

So now you make 8 groups of 7, that add up to 811.6mAh total lost! Give or take a few mA. And assemble a pack.

[Gnomatic]

So now you make 8 groups of 7, that add up to 811.6mAh total lost! Give or take a few mA. And assemble a pack.

That's the plan!

[Gnomatic]

Here are my groupings ....
(60 day static discharge test)

Group 1

Cell 12 - 122
Cell 16 - 109
Cell 22 - 84.3
Cell 23 - 106
Cell 36 - 107
Cell 43 - 95
Cell 44 - 189

Total 812.3mAh


Group 2

Cell 04 -187
Cell 06 - 98.9
Cell 10 - 112
Cell 15 - 106
Cell 17 - 127
Cell 21 - 89
Cell 28 - 91.9

Total 811.8mAh


Group 3

Cell 13 - 185
Cell 24 - 117
Cell 38 - 115
Cell 39 - 90.2
Cell 42 - 99.8
Cell 46 - 106
Cell 53 - 99.5

Total 812.5mAh


Group 4

Cell 02 - 98.2
Cell 07 - 95.8
Cell 09 - 110
Cell 20 - 103
Cell 35 - 121
Cell 41 - 103
Cell 45 - 180

Total 811mAh


Group 5

Cell 08 - 150
Cell 31 - 101
Cell 37 - 103
Cell 47 - 98
Cell 49 - 135
Cell 50 - 122
Cell 54 - 102

Total 811mAh


Group 6

Cell 03 - 109
Cell 14 - 114
Cell 25 - 123
Cell 29 - 107
Cell 30 - 148
Cell 52 - 102
Cell 55 - 109

Total 812mAh


Group 7

Cell 01 - 101
Cell 18 - 147
Cell 27 - 115
Cell 32 - 105
Cell 33 - 108
Cell 34 - 116
Cell 56 - 119

Total 811mAh


Group 8

Cell 05 - 109
Cell 11 - 116
Cell 19 - 100
Cell 26 - 116
Cell 40 - 111
Cell 48 - 117
Cell 51 - 142

Total 811mAh


Assuming my primitive Excel skills didn't fail me, all 8 of my groups are within 1.5mAh of each other following static discharge testing and grouping. I don't see much point continuing to fiddle trying to make that number smaller. Feel free to check my math ....

[Burgerman]

Its only got to be approx. Most people never do this.

[expresso]

yes those are great numbers - 99.9% - cant get better than that i had my chair sitting for months and charges right up just as fast as always - balance etc, - i only charged it once this whole winter on the full pack -

because i was going to use the chair - but then i didnt have to use it - - or else i didnt even have to charge it once -

[Gnomatic]

Its only got to be approx. Most people never do this.

I understand the objective here is to build the pack in such a way to prevent the cell groups from getting too far out of balance during long term storage situations. So just in general, if the static discharge varies between the groups by say no more than 1% after 60 days, its okay to conclude the pack shouldn't have balance issues when it comes out of long term storage. Would you agree?

[Burgerman]

We hope! Things change over time, but thats the best start you can have. After 7 months, on my bed my 3 lithium chairs all charged up and had less than 10 mins re balancing. And one pack is 5 or 6 years old.

[expresso]

We hope! Things change over time, but thats the best start you can have. After 7 months, on my bed my 3 lithium chairs all charged up and had less than 10 mins re balancing. And one pack is 5 or 6 years old.

thats great - - i hope is right - only time will tell how good the pack handles and lasts - mines is still very new - i think i got a good start - but we see this summer how it holds up - and next and next and next

[Gnomatic]

Reading back through your thread for your pack build expresso, and doing a bit of number crunching, it looks like each of the cells in your pack averaged 1.71mAh/day of static discharge. Comparing to the cells I got, my cells averaged 1.84mAh/day on static discharge each in this phase.

Also, the cells you got for your pack have a black negative end and a red positive. The cells I got have a white positive end.

Not that any of that matters really, just a couple observations.

[Gnomatic]

Also, had I not tried to organize my cells by static discharge, and just took the first 7 cells out of the boxes and put in Group 1, the next 7 in Group 2 etc etc, I would have ended up with a 180mAh difference between my lowest and highest group following 60 day static discharge.(had I gone back and measured).

Instead, I got a 1.5mAh difference between my groups. 180 vs 1.5 seems significant, but I have no idea what the real word implications of that would be.

[Burgerman]

Well it means that with a typical BMS that has claimed 50 to 100mA max balance ability, and in reality they never reach this unless miles different. So it would add 4 to 8 hours re-balancing time to a charge after 2 months. 3x that after 6 months. So potentially a day or more.

The PL8 has 1A balance so it will take that about 10 to 15 mins. Or about an hour after winter say. But you were lucky. Sometimes its possible to find a few cells with higher self discharge. Add 2 or 3 of these to a group and then it makes a massive difference.

[Gnomatic]

That makes sense. My average discharge per cell was 116mAh. However, I had four cells that took in 180+ mAh. Had I been unlucky and those cells ended up in the same group, along with four average ones, then I'd potentially be looking at 400+mAh variance between the groups at the 60 day self discharge rate. And rebalancing out of storage would take a really long time...... especially if I was relying on a BMS to rebalance.

[expresso]

https://www.ctsiredcap.pitt.edu/redcap/ ... FTTXAHNK4X

not sure where to post this - everyone should do this and let them know - we need lithium power source - i just did it

[ex-Gooserider]

https://www.ctsiredcap.pitt.edu/redcap/surveys/?s=FTTXAHNK4X

not sure where to post this - everyone should do this and let them know - we need lithium power source - i just did it

Just did, and told them to look here for what is needed in good chairs - probably won't do any good, but...

ex-Gooserider

[expresso]

hey nothing to loose - more they hear from real users - at least they cant say they didnt know -