Battery ADD on pack - First Attempt -

[expresso]

Hi - i decided to start a new thread for my first attempt with making a small Add on pack - i will try to take pictures best i can along the way -

first many thanks to BM and Shirley for taking the time to and effort to guide me so far - Shirley will be making me a BMS for me - i have another 8 Cells coming tomorrow and i think i have most little items i may need for making cables as i need them -

i wont be starting this till i get the BMS and my helper is back and free to do it with me - so early Next year - and first i will use the cells i have to make sure i can fit 72 Cells in my other chair battery try - just to be 100% - before i start the Add on -


i did find this which to read - always nice to find something i can understand - its slowly sinking in -

http://minibms.mybigcommerce.com/templa ... iniBMS.pdf

and i found this - looks to be decent for the price with all the extras needed - but since i am new to this - not sure if this charger is correct and would do what needs to be done - keeping in mind - its not a PL8 - or anything near that class - but for the cost - for a beginner like me - what do you think of one of the chargers on this site -

and with PC software - i know its slow charging at 5 amp i think so may be too slow for a full chair charging - but for everyday small packs etc, -

is this worth it to get and practice with ?

http://www.hobbypartz.com/skychb6chdup.html

http://www.hobbypartz.com/thac6smbachw.html

i have enough invested and i hope to get this done with some form of success with help from here -

i have to thank Shirley for offering to make me a BMS - and walk me thru it - - i couldnt have even got started with out this site and the rest of the users along the way -

so thanks to everyone - but BM mostly for keeping me going - i was ready to give up many times just get a Ready Made Pack - i still think it might have been better for me - - with the costs involved - but i learn a little doing it this way - so well see - if this is a success -- i will consider a full chair - but wont be till i get this done and use it this summer to decide if its worth it for me - the costs involved with a full chair is 3 x what i spent already - or not more -

any input is always welcome -

thanks

[snaker]

expresso, I see the chargers on the hobbyparz links above only support 6 cells balancing. A 24V pack needs 8 cells balancing, doesn't it?

I am saving money for a 'homemade' lifepo4 pack too. I will follow you

[shirley_hkg]

expresso, DO NOT waste money on those non-8S charger. Pick the 8S one if you insist.

Regarding your initial balancing, I'll include a DC-DC power module to bring up lagging behind cells to 3.6V.

One by one , though a bit slow.

Your money has paid for it.

[steves1977uk]

expresso, you'll end up buying the PL8 anyway, so why not buy the proper charger to begin with and then you'll learn how to set up presets. Also you'll be ready for when you do a full conversion to lithium.

Steve

[Burgerman]

You need NO BMS.
You need a PL8 charger.

Doing it with a BMS involves loads of wires, added complication, less effective charging, and ends up less reliable and problematic sooner or later. So at this point you will be on your own!

[shirley_hkg]

expresso, DO NOT waste money on those non-8S charger. Pick the 8S one if you insist.

Regarding your initial balancing, I'll include a DC-DC power module to bring up lagging behind cells to 3.6V.

One by one , though a bit slow.

Your money has paid for it.

Tested on my 80% full battery STILL capable of 423mA .

Powered from your own chair.

[expresso]

You need NO BMS.
You need a PL8 charger.

Doing it with a BMS involves loads of wires, added complication, less effective charging, and ends up less reliable and problematic sooner or later. So at this point you will be on your own!

Ok this is why i ask first - so bottom line - if i do get a charger at sometime in the future - it should be the PL8 to be safe and future proof - - i hold off with the charger for now -

about the BMS - i decided to do it this way as to not invest in the charger stuff just yet - it may prove to be a bad move later or it may be ok - i guess i will find out - i know i was warned

My understanding is Shirley is the best for ADD on packs - has been using them for many years with good results - so with out getting too much involved since i am very new at this - i decided to have Shirley do my BMS - making it simple for me to connect and then i can just charge with current chargers etc, -

that was my goal from the start - since then - learning about this BMS and why it should not be used etc, - i understand now - i hope to make this work and learn from this first time - - good or bad - i am sure i will get a little of both -

worst case - i have to start over and do with out BMS if it really does give me problems that i can not resolve - best case it works good enough and satisfies my goals - even if its not perfect - -

If i check my other chair and decide to ever do the full chair in the future - then i will not use a BMS and have to get more hands on with the charging with the PL8 etc, - till then - i am sure to learn more by the time i get there -

i am counting on Shirley to make this BMS work for me

[expresso]

expresso, DO NOT waste money on those non-8S charger. Pick the 8S one if you insist.

Regarding your initial balancing, I'll include a DC-DC power module to bring up lagging behind cells to 3.6V.

One by one , though a bit slow.

Your money has paid for it.

Tested on my 80% full battery STILL capable of 423mA .

Powered from your own chair.

Ok - i leave it up to you Shirley to make this work out for me - i just need to be guided step by step - - my whole life i been around computer stuff and working with them etc, - my hobbies have been with Audio stuff - electrical - batteries etc, all this - havnt a clue about it till i started using a wheeclair myself and found this site -

so bear with me -

[expresso]

expresso, you'll end up buying the PL8 anyway, so why not buy the proper charger to begin with and then you'll learn how to set up presets. Also you'll be ready for when you do a full conversion to lithium.

Steve

yes makes more sense - PL8 if anything at all -

[expresso]

expresso, I see the chargers on the hobbyparz links above only support 6 cells balancing. A 24V pack needs 8 cells balancing, doesn't it?

I am saving money for a 'homemade' lifepo4 pack too. I will follow you

I guess i need a PL8 - you can follow me - but be warned - i havnt too much a clue - i am new and never done any of this electrical battery stuff Ever - so this is very much a learning first time try - with understanding the very basic -

only way i would even be doing this is because of BM and Shirley - helping me - now - i think you or anyone would have to decide first before anything is - if you are going with out a BMS - or with a BMS - and only you can decide which is best for your needs depending on many factors -

you can follow me with my results and then decide for yourself later - with no BMS - i see how it can be much less complicated with the wires - and less is better most times - but since i didnt want to get into the whole charging with the PL8 just yet - i am taking my chances with a BMS made from Shirley -

life is a gamble - i will learn from it - i wont really know till the summer time when i really use the chair -

[Burgerman]

Ok - i leave it up to you Shirley to make this work out for me

I wish you luck.

[expresso]

What can i do - worst that can happen - i have to start over without a BMS in the future - thats worst case - i made the choice - dont blame anyone for my choices --

i will need the luck either way - DHL - has my package - still at customs - havnt a clue why the tracking shows delivery for today - go figure

no rush either way - i think i be ready to start this in Mid Jan.

[Burgerman]

Regarding the PL8 theres an update to the LiFePO4 / A123 presets. It now allows us to choose 3.4V as the point where the cell balancing begins rather than just at the top, or all the time.

Balancing below3.4V causes cells to become UNBALANCED at the top. So now is the time to set cell balancing to 3.4V and over, to proportional not digital, and to 1000mA. Rather than ONLY at CV. And to 2 or 3mV accuracy. And starting at -1mV. Also require ALL CELLS TO BE AT CV. And ALL CELLS TO BE BALANCED before termination. Set CV to 3.550V per cell for long service life. 3.600V for faster charge ending. 3.650 volts to kill the pack faster!!!

[expresso]

I know this is a little ahead of myself - but when i get this finally all done - do i have to pack in a box or cushion it - or wrap it with something to keep it safe from vibration etc, -

My Backpack i have is more like a Messenger bag - no cushion in it - do i have to put it in a plastic container - which i would have to find one that fits or make a home made box for it -

Any suggestions what i can use or how do i have place it in my bag - i guess i would have to strap the bag also so it wont move as i ride -

i am far from this part - but good to know before hand - the Ready made packs are fully covered in some box with plastic sealed around it etc, -

is that what i have to do also ?

[Burgerman]

As long as nothing can short it out its safe. Put it into a small makeup type case that girls use, thats a close fit. Preferably with a handle... Wrap in bubble wrap for eg first.

https://www.google.co.uk/search?q=small ... +hard+case

If its using a BMS make sure its also fire proof...

[expresso]

Oh ok - i didnt know - yes it will be with the BMS - - so i have to wrap it in fireproof material - that sucks - what Can i use - is this something common i can buy to wrap it in thats fireproof ?

i hope i can find something thats not bulky -

[Burgerman]

I was joking...

[expresso]

I was joking...

Oh ok - i take what you say for real - i know you know best - ok i feel better now - so any container that fits it is fine - i can leave it just as it is when its built and place in some container with bubble wrap for cushion ?

[expresso]

http://www.batteryspace.com/PVC-6.49-in ... Packs.aspx

You think i should wrap it with this - to cover most of it and then finish it off with Duct tape or something like that

to be honest i though i could just leave it alone and just place in a plastic container if i can find one thats fits it just right -

i did get the torch - for future wires - i could use that to shrink this over the bulk of the pack ?

[shirley_hkg]

Did you ever see that before ?

[expresso]

on your chair - that fits nicely -

my chair back is not as flat and i have the bar going across - which i am thinking of strapping it on the bar - in the bag first

this is the bag i carry in the rear with a 20amp charger in it - my vision is to replace the charger with the pack - i hope this bag is good enough to hold it

http://www.amazon.com/gp/product/B0031Q ... ge_o08_s00

it may fit - but now if i have to stick the pack in a container - that maybe harder to fit - have to figure that out when the time comes - -

Shirley - i never asked you before - i wasnt thinking - is this BMS you are making for me - how big is it ? etc, - would i be able to tape it to the side ? which then makes it wider -

about 5 inches wide when all done ? i know its about 12 inches long by 8 high approx. -

[expresso]

Shirley - i like that little stand you put in the rear for someone to stand on and ride around -

[Sully]

I also like that little platform, does it work as well as it appears to? I can walk much further, faster with my chair than my wife can on her own. This would be a good solution for that problem.

[Burgerman]

There's a vid here somewhere with it in use. But I cant find it.

[shirley_hkg]

There's a vid here somewhere with it in use. But I cant find it.

https://www.youtube.com/watch?v=TT53Cl1 ... e=youtu.be

You want to watch it again ?

This is a 20 miles trip to the nearest railway station.

The guy right in front of me is using chin-control . Impressive . itsn't it ?

With lithium power, we always do 30 , 40 miles @ charge , effortlessly.

[shirley_hkg]

on your chair - that fits nicely -


Shirley - i never asked you before - i wasnt thinking - is this BMS you are making for me - how big is it ? etc, - would i be able to tape it to the side ? which then makes it wider -

about 5 inches wide when all done ? i know its about 12 inches long by 8 high approx. -

It is the size of my S4 .

[Sully]

I think I would call that clip as, "minimum transportation maximum load" they were so loaded down I could not identify what chair they were using, and they were moving quite fast.

[expresso]

There's a vid here somewhere with it in use. But I cant find it.

https://www.youtube.com/watch?v=TT53Cl1 ... e=youtu.be

You want to watch it again ?

This is a 20 miles trip to the nearest railway station.

The guy right in front of me is using chin-control . Impressive . itsn't it ?

With lithium power, we always do 30 , 40 miles @ charge , effortlessly.

Very nice - you use just your Lead batteries and the ADD ON pack to do your 30 to 40 miles a charge ? what size is your ADD on pack ? and your using a BMS ? for a few years - any issues or problems during that time ?

[Burgerman]

Shirley has brushless, (more efficient motors) and a full lithium battery.

[expresso]

Oh ok - i though he used an ADD On - from the last picture i seen

so he has a full chair pack - nice -

that sounded great for just a Add on