PINNED - Lithium battery conversion/info

[expresso]

In your Case - i can see the reason you do it your way - you need it - and you have the knowledge and know how to do this correctly - i live in the City - i do fine at my 8.5 speed - many times i have to go slower - because of people - other wheelchair users are not as fast and because of all the bumps and cracks in the sidewalks and streets - i do full speed when i can - for me in my case - i would love to at least extend my battery life - so i can stay out longer and not worry about being in the RED -

if i get more speed in the process - great - but the battery range would be great - i do fine now also - and so far i never had to use my charger while i was out - come close but was fine - for me - i can wait till something in the future to come out and see - now if things change and i have to pay out of pocket for batteries which i dont know - i dont want to just spend all that money to do it myself -- but i like the idea and i dont fully grasp whats involved completely - i read your page over a few times to understand -

maybe one day who knows - i may give it a shot - if i ever do - i will be asking you alot of questions to get the correct parts - nuts - bolts - wires etc, - i would need everything from scratch -- for now its just a idea that can be done but most likely wont be doing it anytime soon -

i would need help physical help from someone who is willing and at least on the same page when talking and explaining etc, - or else its like having one your PA helping you - unless and frustrating - PA is short for Personal Assistant - that works for you - its great that you do this and do this forum also - its one of a Kind

[shirley_hkg]

Have been looking for charger with at lease 8 individule charging channels , and finally get one.

UN-A9+ is capable of 9 cells at 8A max.

Now battery is charged to 28.2V through a BMS, which has over-charge cutout at 3.65V , during normal routine charging. Then use UN-A9 to balance the cells once every 4-6 weeks.

.
http://item.taobao.com/item.htm?spm=a23 ... 6837493315

[Burgerman]

Why not scrap the BMS before it does damage, and use the 20 Amp Hyperion 14 cell 1420i, or the 30 Amp 8 cell 730i? Or the 8 cell celpro 1300 watt charger?

And charge with these full time?

[shirley_hkg]

UN-A9 charges with individule channels ; that is balancing current is the charging amp --ie 8A max.

[Burgerman]

Really? But that would melt the tiny balance wires and connectors on every hobby pack?

[shirley_hkg]

I tried 5 amp for 7 hours and feel just a slight warmth on the wires .

[Burgerman]

Not sure how safe that is...

But that would be OK for charging my transmitters etc.

How much? In UK pounds? And is there any specs anywhere in English?

[Irving]

Really? But that would melt the tiny balance wires and connectors on every hobby pack?

Yet that seems how its done....

charging.png (83.42 KiB) Viewed 13545 times

[Burgerman]

Do you think charging or balancing at 8 amps down less than pin sized wires and equally tiny connectors is a good idea?

If I charge via a balance connector as I do on my RC transmitter, they get quite warm enough at 2 amps!

If I charge at 30 to 40 amps, from my power supply to my chair, the 10sqmm cables and big Anderson connectors get very warm. That's massive in comparison. At least 20x the cross section.

I would have thought that 3 to 4 amps was pushing your luck.

[shirley_hkg]

Not sure how safe that is...

But that would be OK for charging my transmitters etc.

How much? In UK pounds? And is there any specs anywhere in English?

This seller speaks English , and it sells at US$ 66.00

http://item.taobao.com/item.htm?spm=a23 ... 7825630786

[Burgerman]

http://img01.taobaocdn.com/imgextra/i1/ ... 447737.jpg

There are 3 items plus a small connecting board.

What are they.
Power supply (OK), Charger (OK), and the 3rd thing covered in connectors?

And does the price include 1, 2 or all 3 things?



And...
Are all the grounds connected? So could it be used as a pair to charge up to 18 cells without smoke? And is the firmware / software any good? As in is it flexible?

[shirley_hkg]

http://img01.taobaocdn.com/imgextra/i1/20447737/T23TDyXgXaXXXXXXXX_!!20447737.jpg

There are 3 items plus a small connecting board.

What are they.
Power supply (OK), Charger (OK), and the 3rd thing covered in connectors?

And does the price include 1, 2 or all 3 things?



And...
Are all the grounds connected? So could it be used as a pair to charge up to 18 cells without smoke? And is the firmware / software any good? As in is it flexible?

This is a nanny which extends the charging flexibility and adds discharge feature to UN-A9.

Price is for charger only; nanny and power supply are sold seperately. Complete set cost US $120.

[Burgerman]

Shame no 14S version - be useful for balancing new or stored packs.

[shirley_hkg]

Good tools for 24V user.

[Burgerman]

Yes for either balancing or small hobby packs.

If it really balances at 8 amps.

I am tempted to try one for my hobby stuff. So I can plug in many assorted 2, 3, 4 and 6 cell packs at once.

[Burgerman]

Yes for either balancing or small hobby packs.

If it really balances at 8 amps.

I am tempted to try one for my hobby stuff. So I can plug in many assorted 2, 3, 4 and 6 cell packs at once to save time.

I do this now with the Hyperion and the thing has a nervous breakdown. It gets there in the end but it takes time.

[shirley_hkg]

8 AMP should be used for short time. I tried 5 amp for over 10 hrs and it does not get hot. Seller recommends 6.5 amp max for prolong charging.

Shame no 14S version - be useful for balancing new or stored packs.

GET 2 !

[Burgerman]

Common grounds mean it wont work on 10S helis, or 13S powerchair without smoke.

[Irving]

Common grounds mean it wont work on 10S helis, or 13S powerchair without smoke.

Nope, you have to split stacks into packs of 2 - 6 cells.

[Burgerman]

My chair is 13s doesn't split. Heli packs 10s doesn't split. Many ebike and scooter packs are 12s and don't split. So it wont work for me or them.

Like these:

https://www.hobbyking.com/hobbyking/sto ... Order=desc

Or 12S


https://www.hobbyking.com/hobbyking/sto ... Order=desc

Most powerful model helis are now 10s and smaller capacity as you get better performance with no loss on hovering time etc.

[ex-Gooserider]

If you got two, it might be possible to figure out how to "float" the grounds on the second unit so that you could put them in series... Sort of along the same idea as how some folks will float the grounds in PC power supplies so that you can connect them in series for more than the usual output voltages...

ex-Gooserider

[Irving]

If you got two, it might be possible to figure out how to "float" the grounds on the second unit so that you could put them in series... Sort of along the same idea as how some folks will float the grounds in PC power supplies so that you can connect them in series for more than the usual output voltages...

ex-Gooserider

could probably work if the common ground is wired back to the -ve supply input and your power supplies were floating outputs and you only did one stack... so second unit 'ground' would float at voltage of first part of stack. then again it could be a recipe for letting magic smoke out....

[CPguy]

Forgive me, I am not close to the manual or tools now. Embarrassing! On a Hyperion charger what size are the charging and balancing wires please? (metric and imperial please?) Thank you ever so much!

[Burgerman]

Balance wires, no idea. But the shorter they are the better. If you make them longer then use a slightly heavier gauge too.

Same with charge leads. I use 10sqmm charge, but that's probably overkill.

[CPguy]

@ BM. Thank you very much for the information!

[mous3]

My LiFe's will be hear in the morning and not day to soon as led pack is totally dead now having to run off emergency12ha pack hope they can last a few weeks whilst making up the pack. I was not going to have a split pack but my new 10s charger got caught up in the flooding. Now waiting for new shipment, leaving me with my 2x 6s chargers any suggestions?

[Burgerman]

When they arrive, charge each cell to 3.600 volts at 2 Amps. Tell it the true capacity. And let it sit at this voltage still on charge, floating, for at least 30 mins or so after charge "ends". Your charger should allow this.

Label this cell with a 1. Do the same to the next cell, and label it 2. And then 3. etc etc. Its boring but important.

Put them all in a box, leave in a cupboard or under a bed for about a month. And forget about them. If you cant spare a month, then as long as you have. At least 2 weeks...

Then charge each one individually, to the same 3.600v and slowly at 0.2 Amps. (200mA).
Make a note of the CAPACITY returned to each one individually. It will only be a few mAh...
It will tell you on screen or on the charger.

Type this figure in notepad or something, next to each cells number on your PC. This is the measurement of the cells SELF DISCHARGE over a long time period.

Its now easy to assemble your parallel groups, using your calculator and simple maths (adding up) with the same TOTAL mAh returned. These are your groups of cells that will be all connected together as a big single cell. This means each "group" will stay in balance in use MUCH better, even if stored for a long time.

After you finish, remove about 40 percent of the charge accurately from all cells to store them long term. Your charger will have a "store" command. Don't use that. Remove say 4Ah from each cell. As accurately as you can.

Then you are ready to build the pack...

[mous3]

Thanks I will get on with the individual charging and matching you advise but I am correct in my assumption that I a stuffed on using my new pack until charger turns up
I am off to cruffs later praying they will let me charge up as i will run out more than once

[Burgerman]

2x 6cell chargers?

Well if you used 2 separate power supplies that were FLOATING, ground wires not at the same potential you could charge it as 2x 4 cell packs. Or charge first 4 cells, then the other 4 cell later on.

But not really practical.

And ideally you need to fully charge all your new cells, and soak charge them, so they are FULL. Then store them for a week or 2. To find self discharge rates.

[daddywoofdawg]

trying to understand.
would this work?or am I looking at the wrong type?
http://www.ebay.com/itm/A123-ANR26650M1 ... 0863056969