48v drinks bottle battery.

[Nealh]

Following on from d6veh's 36v bottle battery in thread below.
http://www.pedelecs.co.uk/forum/threads/how-to-make-a-lightweight-battery.28437/

My needs is for a 48v 2p 13s configuration using 26 cells.
Bottle from Aliexpress with bottom removed from the very base of the bottle using a Dremel type tool with thin disc cutter.

The yellow A4 sheet underneath is 0.4mm epoxy glass fibre sheet heat resistant to about 180c, for cell face separation and for the panel mount charge port in the lid.

For the base insert I am trying a desk cable tidy 80mm.
Using the Dremel tool and a fine straight reamer, I removed a thin layer of material a round the base upstand to allow the base to fit inside the bottles base and removed the bottom lip


Bottle with base fitted (push fit snug/tight).

Not easy to tell but the 12 cells are sitting within the base.
The middle tier 8cells will sit on top of these.
The orange strips donate the series connection on the under side the white strips the series on the top side.
10+ to 9- is the only awkward series connection and a slightly longer connection for safety 11- will have an insulator as well on the end.
8+ will have series connection to 7- which will sit directly above via a nickel strip with 180 degree crease.


Charge port wired and mounted.


Lid views ext and int with dry fitted charge port ready for epoxying later.

Cap not fitted but as per d8veh thread needs a few mm removed to screw down with out putting pressure on top panel mounted.

 

[Nealh]

BMS hasn't arrived yet, the plan is it will fit between tier 1 & 2.
Hopefully the 25a one I found on Aliexpress had the correct measurements that should enable it to fit.
Not purchased cells yet but probably will go with 30Q's.

The main build of cell pack and fitting is for next year late winter maybe, I'm not ordering cells yet as I may be in need of some for Swizzbee #2 battery pack of 8p 7s.

 

[KirstinS]

Great thread nealh, watching this one closely



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[Nealh]

It will be a slow burner this one Kirstin, not thinking of buying any cells this side of the year, my next step is to make up a cardboard mock up of the upper battery tiers so that I can checking fitting/ placement of the BMS when it arrives.

 

[KirstinS]

Works for me Neal

This project is as at least 6months away from even starting for me


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[anotherkiwi]

Will 20700's fit in there is my question?

 

[Nealh]

Will 20700's fit in there is my question?

Yes probably but should think only as 12 or 13s 1p in two tiers .
10s 2p might be possible but then a bms is needed though 36v ones tend to be a bot smaller then 48v.
You can cut a disc 78mm and have a play with 20mm coins, washers etc to see how many. Internal height to shoulder is approx. 190mm . Using 650's the top tier is placed in the middle a little more to give about 195 - 200mm in height.

 

[Nealh]

My waterproof bms arrived today along with two others I ordered to convert my 4 Graphene lipos to two 10s lipo with bms.etc,et.
The bottle battery bms it is sealed and encased in a ali/rubber enclosure width is 61mm x 75mm high x 9mm thick. On my scaled plan the bms comfortably fits inside between tier 2 & 3.

 

[Nealh]

Made up a cardboard mock up of tier #2 and #3 to go on top of the real cell tier #1, along with ample room for the 13s bms to fit in to the water bottle with base on.

 

[awol]

My waterproof bms arrived today along with two others I ordered to convert my 4 Graphene lipos to two 10s lipo with bms.etc,et.
The bottle battery bms it is sealed and encased in a ali/rubber enclosure width is 61mm x 75mm high x 9mm thick. On my scaled plan the bms comfortably fits inside between tier 2 & 3.

Which BMS's did you get to use with your graphene lipo's? I could do with a couple for those same lipo's

 

[Nealh]

Best to start a new how to thread, I will post a how to thread.

 

[Nealh]

Back to this old chestnut revived following Kirstins lockdown mini pack build.
I have 2 dozen LG hg2's coming from a UK wholesaler so will see if I can get 12s2p inside, I know 10s2p fits with a waterproof bms and am pretty sure 24 will fit, all coupled to a 12s 20a continuous lion Bms with 60a peak discharge.

I also looked at the Molicell P42A 21700 but will struggle getting 20 inside.

 

[Nealh]

For the interconnectors/buss's I'm going to try copper welding with the malectrics welder, the guys on ES have been experimenting and seem to have come up with a solution to spotting copper which I haven't yet tried out. It appears that nickel placed on top of thin copper sheet is the way to go and passes through the copper with out issue thus you get the advantage of the superior opacity of copper.

0.08mm copper x 26mm will provide ampacity of 33a and with two 0.15mm x 7.5mm nickel buss tops will add another 10a of ampacity. The nickel top acting as the welding catalyst to penetrate the copper indirectly is also the strength link between cells as copper is inherently soft and could fracture/tear on its own.
In between each cell layer will be a 0.4/0.5mm grp insulator to prevent shorting of cells.

 

[Nealh]

Ordered 24 HG2 Monday late afternoon, arrived this morning before 10am.
Fantastic service from a UK wholesaler.
Batteries all at 3.54v from the factory and dated marked R361L which donates they were produced on the 361st day of 2018. R is year date code (18th letter in the alpha bet) , 361 self explanatory and L may also donate December as the month as well being the twelve letter of the alphabet.

 

[Benjahmin]

Batteries all at 3.54v from the factory and dated marked R361L which donates they were produced on the 361st day of 2018. R is year date code (18th letter in the alpha bet) , 361 self explanatory and L may also donate December as the month as well being the twelve letter of the alphabet.

WOW ! Now I know you work for GCHQ

 

[Nealh]

All branded cells have a date code but use different codes so you need to know them to cypher the date of production.

 

[Nealh]

I revisited this one today as the wind was too strong with the cloud's today so not ideal for me to check the bee's out, tomorrow is looking better with a few days ofvery warm weather to come.
My cell holders arrived last week so after fiddling about I managed a dry fit with the 24 HG2's inside the water bottle along with the BMS and all the wiring.
To the base I mounted an XT60 male for the discharge .
No pics but they will come when I start spot welding in the months to come.

 

[Nealh]

Sorry guys I never did take any pics of the build as I went along but did get all 20 HG2's inside with 12s waterproof BMS and all the wiring. One of my 36v Sans was able to have the V trim pot turned up to 50.1v to allow cell charging to 4.175v so this is the max I charge to without buying another charger. Having built and finished it, I only finally got around to fitting it last week and it sits in an adjustable water bottler holder with a plastic cam buckle strap so it doesn't bounce out.
Capacity is 264wh and I reckon about 30 miles range is doable if not a bit more, I will drain to lvc once to see total range possible. The two older 36v 29E batteries it has replaced were getting tired and sagged quite a bit, my fault as I stressed them in early life some 4 years ago and they have soldiered on quite well. The performance difference of the 12s/44v is certainly a lot better and as we know acceleration is improved to due to the extra torque 12s gives over 10s, I got fed up with going fast so derestriction I find a boring now, I prefer to ride above the cut off speed under my own steam and my bike cuts out at 16.7mph and am quite happy at tootling along up to 20mph with no assist.

 

[vfr400]

Nice one, Neal. I never thought of 12S. I'm kicking myseld now. There's probably room in the top for two 6S ballance connectors to charge with a lipo charger, so no need for a BMS. The problem is health and fitness going down, so light-weight solutions might be a thing of the past.

 

[Nealh]

It's thanks to you and your previous postings of your bottle battery that I used to make mine. The simple genius bit was your use of the cap to glue in the charge port.
Though the space looks enough for a pair of 6s balance connectors the lid will reduce it even more so and in reality there is very little space
The cell layout in #1 was abandoned as too iffy for interconnectors and fitting.

This is the cell layout option, 24 LG HG2. Wrapping in shrink would make fitment to tight so I use cell holders to give cell protection and a mm spacing for cell can to drink bottle inner face. The remaining 3s sits in the arc void so are laid on the side of the first 9s cells, although cell holders are used between the cells I have used fibreglass reinforced tape to prevent shorting where they may touch. Otherwise all exposed cell ends and joints are taped over with Kapton and all is bound together with Kapton.
I still uses insulators added to the v+ end. Interconnectors I use a 0.08mm cu & Ni 0.15mm sandwich for current supply, thanks to the guys on ES for this one. Copper spot welds to cells using my malectrics welder by using the Ni on top, the Copper fuses to the cell where as on it's own it doesn't. End to end cell abutment by folding the interconnectors.





Bms is a Dalegreen 12s 25a rated std tri port model, I was going to use a dual port one but couldn't find one in 12s. 12s is very tight and snug and it only just slides in carefully so no rattling around as the edges of the cell spacers against the bottle walls prevent this.





The only bit I couldn't link with interconnectors was the group #3 to #4 so a very short piece of single 12awg was used. Bisecting the connection from each cell group equally takes the current share, instead of soldering direct on the cell end I cut the interconnector bigger so I can bend the tab over the side and soldered the connection to it first then I spot welded the interconnector to the cells.
Excuse the blurry image.



XT60 glued in place for discharge.