HUGE EMPTY Downtube/Craddle Battery Box with Keylock

Matador

100 kW
Joined
Jun 29, 2016
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1,045
I've spent quite some time on researching this...
Maybe some of you ES members can point me in the right direction.

The main thing that I notice is that it's REALLY NOT EASY to find an EMPTY Downtube Craddle Battery Case sold without friggin cells inside of it ... Easy to buy the case already filled with "some 18650" cells and BMS inside.
I dont get what's the deal with small boxes ? Can't they make bigger downtube craddle box ? I want to cram 140 cells, not 50 ! Make battery cases removable from sideway latching action and it's still easy to remove a much bigger pack from it's craddle.
They're all 4P 13S tiny boxes ... but if you glue cells you can cram maybe 4P 14S.... There is maybe one model allowing for 5P... Is that all you've got China ???

I've got many good 18650 cells... Got them for about one fitht of the price I would pay them brand new, taxed and delivered to my door taxed. Mine are not new, but all under 100 cycle usage. They're NMC 2100 mAh and capable of 30A continous-100A burst/cell.

I tested each one of them at 1A discharge (each individual cell) and they are on average 2173 mAh (lowest 1983 mAh, highest 2309 mAh from 4.20 to 2.70 V... probably 95% of them being between 2100 and 2200), are between 1.7 anf 4.0 years old (from date code when manufactured at Koriyama Japan (70km from Fukushima nuclear plant) to this very day ... Dont worry, I checked the lot with my Geiger counter... not radioactive at 0.14 uSv/h ; just like the normal background cosmic radiation level in my house). I discharged them back to 3.65V (45-50% SOC) for storage as I'm eventually planning to assembe them into packs this early June... I measured one of them cell at 22 milliOhms DC (slope of graph with 5 different load resistors), while they're rated at 12 milliOhm AC impedance at 1 kHz. Pretty awsome for a 1.9 yr old (but almost virgin) cell (supposed to be 23 mOhm DC brand new !).

I got 286 of them cells... In case you want my data on these cells : View attachment Makita VTC4 cells from doctorbass.xlsx

VTC4.jpg1box VTC4.jpg3box VTC4.jpg

Back on topic now...
I've seen 4 types of battery box that I could fill up with my 18650 cells.
I want the box to look like an OEM battery from the outside... No cardboard or wood. Factory look is what i'm looking for.
It's going to be heavy (45 grams per cell) so it HAS TO HAVE a STURDY CRADLE to hold the pack. Ideally, the pack would be lockable, have some cute little led to display charge percentage

The thing is... I cannot go less than 14S5P as a very bare minimum (70cells)... Remember, my cells are just 2.1 Ah. And I like that because they are 15C cells so they will live a long life at less than 3C (ideally, I'd want to be at 1.5-2C... My BBSHD's controller is still at 30A for now... although I got myselfs some current sensing resistor to do the controller shunt mod in the future... to upgrade to 40 or 60A!).

QUESTION : Anybody knows where I can find such a craddle factory looking sturdy Downtube battery case to fit 140 cells ideally (14S10P - 52V, 20Ah, max 300A). I'd still be very happy to cram 112 cells in a case (14S8P - 16Ah, max 240A). For me a small but still intersting pack would be capable of holding 84 cells (14S6P - 12Ah, max 180A)... With my calculations and my riding style a 6P pack would give me 11.7 real Ah and I would not do more than 20-30 km on it (will only charge to 85% SOC and never discharge under 20% SOC)...

A 4P pack would be too small for me.
All I could find was these 4 boxes :

Hailong1.jpgDolphin.jpgTiger Shark.jpgCarbon Shark.jpg

Seriously, isn't there anything bigger than that for a downtube craddle ???

Ideas please ! Anything bigger ? I live in cold Canada (sometimes -40°Celcious in winter), and want to be able to remove my battery to charge it and not let if freeze.
Could not find a thread on different MODELS of Downtube battey boxes available on the market to DIY, so I decided to create this thread.

Seriously, I'd really love to get an 14S8P downtube box...

Matador
 

Attachments

  • Specification_US18650VTC4.pdf
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Forgot to say, I'm also planning to have my BMS inside the box. This Bestech one to be exact (80A continous, 200A maximum) : https://endless-sphere.com/forums/viewtopic.php?f=14&t=87134&p=1284752&hilit=autopsy+of+bms#p1284752.

My bike has lots of triangle space...
It's a "Nakamura"19inch hybrid bike an the space inside triangle is : Vertical tube : 13.75 inch, downtube 25 inch, horizontal upper tube 21 inch.
IMG_0412.JPG
I really want to avoid a "flexible", no-rigid triangle bag. I'd wont something rigid, removable and somehow water-/weathe-resistant.

Matador
 
Reetetion : http://reention.com/product/1
Make battery cases (good reference for serial numbers).

I'm thinking I shoud buy two or even 3 cases of the TIGERSHARKS DS-6C Black. Do a dremel job an than a fiberglass (no experience on the fiberglass part) and than a bondo job + paint to expand the pack to hol 14S8P or even 14S10P.

The cradle looks sturdy.
 
split the pack in two and use saddle bags on the rear carrier... look for horse saddle bagsas they aresmaller than motorcycle bags... horse abouy 10x11x 4...motorcycle..about 11x 12 x6.. I am using 14sx20p in a split pack..
 
kriskros said:
split the pack in two and use saddle bags on the rear carrier... look for horse saddle bagsas they aresmaller than motorcycle bags... horse abouy 10x11x 4...motorcycle..about 11x 12 x6.. I am using 14sx20p in a split pack..

I thought about it. My concern with saddlebags on the rear is about the weight on the back causing an unbalanced. I chose the BBSHD motor kit because it keeps center of gravity low and centered thus handls like a champ.

Maybe I can cut the to part of the Tiger Shark pack and make it so that it can store twice as much cells.... Fiberglass, bondo, paint.

Why don't the make readily available bigger packs ?
 
Anybody sells a rigid triangular battery boxes like the sondors has ?
Googled everywhere, I can't believe this doesn't exist
 
rojitor said:
Have you considered frog? Room for 100+ cells
36 V caja de batería de 48 V bate...ss.com/VbIf2iqE (from AliExpress Android)

Thanks for the reply.
I've seen it on alibaba.
Good cell number... but i'm really ainming to put my battery inside the trangular space to keep the bike with a low and very centered center of gravity.
I'll still check out thr frog in bigger details.
 
Ideally, I'd want something like this if it existed :
ae6a3ae519d7cb40c129ebb3e3a73119 - Copie.jpg

Right now this is the biggest I can find on the market (room for just 65 cells).
ae6a3ae519d7cb40c129ebb3e3a73119.jpg

The battery has to be removable.
 
Some cases are designed to be removed sideways, so height should not be a concern so much.
Like this one :

Right not i'm heasitating.
Either I buy a cas and cut it open to do fiberglass, bondo paint and expand it's size (Crazy labor intensive)

Either I fing a permade triangular box. I can't even find a place to buy a sondors triangle box to begin with.
 
These are cool, but 250+ $$$
21584.jpg21585.jpg21583.jpg
https://gearjunkie.com/ak-codepak-bike-bag

Called the Codepack (Kickstarter.....)

Video of the Codpack:
https://www.kickstarter.com/projects/2039923878/ak-codepak-bike-cargo-solutions
 
I think nobody has tough of commercializing what I'm really looking for.

I'd want a rigid triangular frame box to cram in lots of cells, a bms and a battery indicator.
The triangular box I imagine would be easily removed by strong metallic latching mechanism.
There would be a cradle made of metal to attach it in a very solid way.... That cradle could even span on 2 sides of the triangle frame for more solid grip (attached by 4 screws to the frame).
 
Ashland ebikes triangle case (on Pinterest).
Dunno where to buy it but looks good.
320a3331b7ec767203cead59ae50ad77.jpg
 
What about two separate cases, one on the downtube and one on the top tube? Not ideal, but might be able to use off the shelf parts.
 
fechter said:
What about two separate cases, one on the downtube and one on the top tube? Not ideal, but might be able to use off the shelf parts.

Finally bought two of these empty kits (should fit 14S5P 70 cells if I get rid of the holders...)
56$ per kit (case, cradle, connector, battery meter).
View attachment 1
Got 2 + 16 $ DHL shipping.

Expecting a little DHL surprise fee at my door but seller agreed to declare each pack at 30 USD rather than 56, as some of the cases he sell really retail for 32 $ on his website...
A 34 CAD surprise to be exact :

So each battery case kit comes down at 105 CAD (USD) after taxes, customs, and shipping...
Bit pricey, but I was not satisfied with the idea of a 4P or even 3P pack. Even with 30amp rated cells... I went them to live a long life.

Who know, I might even choose to mod one of the battery case in the future... to increase capacity (as long a the cradle can hold the pack unde high G-force in x, y and z-axis).
A little fiberglass there, a little bondo here, a little sanding there, a touch of black paint here. :wink:

There is that one seller on aliexpress who actually has a great choices between around 20 to 30 different models of empty battery cases (lot of downtube models too). He does not sell ready made packs with 18650 cells inside, but he has 100% good feedbacks (n = 267).
There's even an aluminium one that can host 120 cells or so. and it slide onto a metal plate "cradle", but the box is squary, not for downtube postion.
 
Quick view on different battery casings :
[youtube]B_leLpKVxuw[/youtube]
 
https://endless-sphere.com/forums/viewtopic.php?f=6&t=11765&p=603605&#p603605
Oatnet onn Friday June 29 said:
Jerry, at Ashland electric bikes, had completed a model, and was looking to do a production run. Send him a pm I'm sure he'd be glad to hear from you.
wavetrack closed its doors October 2006, soo yeah, when.
sure, just like today is 'when'.

pm these two, see if he's even still into it.
may need to gather together a group buy for him to get it up one more time.

https://endless-sphere.com/forums/memberlist.php?mode=viewprofile&u=18440
https://endless-sphere.com/forums/memberlist.php?mode=viewprofile&u=533
 
This one empty alloy case is pretty cool also. Quite gigantic...
I think it can contain up to 96 cells, judging by the inner dimension ! But it's for a rear rack, so that can be a pitfall for the center of gravity :
[youtube]wE4kWhu4qbU[/youtube]


I think this is about to become the "Where to find empty battery case, and what are the options for a huge batteruy case" thread.
 
999zip999 said:
Diy. Just make one. You have the skills. You said 140 cells custom. That means you.

I'd love to. Just too busy with work these days...
 
Okay, so I recieved 2 x Tiger shark empty battery cases. They are meant to fit 60 (ex: 10S6P) to 65 cells (ex: 13S5P) when you use the cell holders.
Tiger%20Shark.jpg4 insets.jpgCase2.jpgBMS 30a.jpg
All in all. I'm happy. I ended up having to pay only 22 Canadian dollars at the door for custom duties and tax by UPS (declared value was 30 USD rather tha 56 USD per kit).
So with shipping and duties. Each case (includes craddle, key lock, 48V voltage display,ON/OFF switch and USB phone charging port) ended up costing me 99$ CAD every fee included (72 USD) per kit.

I have a 14S Li-ion charger (58.8V @ 5A) I got from Paul at EM3EV.

I want to do 14S5P (70cells). The only way I can see this to fit is to just hot glue the cells togeoether (BMS fits too, but very crammed).
This is very crammed but it should fit. I made a simulation with laptop cells. You can see that I have to put 2 cells in a special position (the voltage indicator bumps on the alien placed cells otherwise).
Test.jpg

I managed to put the BMS on the upper left part. I's really crammed.

What do you think. I'm kind stuck doing it 14S... Got 14S BMS and 14S charger....
BTW picture is just a Mock up... No way I'm filling it with cheapo laptop cells. I'll fill it up with some Sony VTC4 cells with some already soldered nickel plated copper tags you just saw above : https://endless-sphere.com/forums/viewtopic.php?f=14&t=88415&p=1299070&hilit=vtc4#p1289715

Matador
 
Also I was thinking of using the "slide and solder" 9mmx1.7 mm Copper bussbar technique for wiring P-groups togoether. But I'm now wondering if it's going to fin inside...
Like this https://endless-sphere.com/forums/viewtopic.php?f=14&t=84791&p=1275079&hilit=tags#p1273439

Copperbussbar are 100A ampacity. Would it fit....
I also had tinned copper braid (a 50 feet roll that's supposedly 30A ampacity), I could alos solder that instead : this one to be exact : http://www.ebay.com/itm/50-Ft-Flat-Braided-Tinned-Copper-Wire-1-4-Wide-Ground-Strap-USA-/302037112727?hash=item4652d09797:g:q0sAAOSwU-pXqIpM
Or I could go buy solid copper wire.
I also bought nickelstrips.... but I was a noob at that time, and it ended up being nickel plated steel... doh! This to be exact : http://www.ebay.com/itm/0-15mm-8mm-10meters-18650-battery-nickel-strip-nickel-plate-li-ion-cell-nickel-/111844645318?hash=item1a0a75d9c6:g:yuoAAOSwHQ9WZlV4&vxp=mtr

So what's your vote ?
1) Copper bussbars (100A)
2) Copper braid, tin plated (30A)
3) Solid copper wire
4) Steel strips plated with nickel (maybe good for 2.5A)

Any input appreciated. I'm aiming at building a good quality pack, with quality cells.

Matador
 
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