Need a plastic case for battery pack

I just finished my battery and am looking for a plastic case to put it in. Preferably something enclosed with a top. I did find a some cases designed for $300 in rolled quarters that is about the size I need, ordered it and will see. This is for a cargo bike so it doesn't need to be compact.

Dimensions are 11.5 x 3.5 x 3.5

It's a rectangular 14s4p design in holders.

Anyone have a good case to put it in?

Click for large view - Uploaded with Skitch

You can make your own with just hand tools.

I did mine with no prior experience, 2mm polycarbonate. Just needs a good heating before bending it to make it both strong and permanent. Then wrapped it in carbon fiber vinyl from aliexpress. Material costs $20.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=88921&start=100#p1414867
https://endless-sphere.com/forums/viewtopic.php?f=28&t=88921&start=100#p1421835

Tommm said:

You can make your own with just hand tools.

I did mine with no prior experience, 2mm polycarbonate. Just needs a good heating before bending it to make it both strong and permanent. Then wrapped it in carbon fiber vinyl from aliexpress. Material costs $20.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=88921&start=100#p1414867
https://endless-sphere.com/forums/viewtopic.php?f=28&t=88921&start=100#p1421835

Click to expand...

This looks like a good plan, I was thinking of just building one but wasn't sure of what material to use (I have a lot of experience with sheet metal and wood)

Did you just use a heat gun to bend the polycarbonate?

Go to Home Depot and buy some PVC pipe and see how much the Heat Guns are, if they are not on sale then go to the Thrift Store and buy an iron. There are threads here on E.S. with people doing that for a case. I am thinking about doing it myself for my own portable enclosure and using very wide velcro to mount it on the frame.

All sort of empty battery case are available on alibaba, from 5$ to 25$

Your 14s4p does fit in a standard dolphin case

RichW_SC said:

Did you just use a heat gun to bend the polycarbonate?

Click to expand...

I used a hair dryer, but the heat gun would of been idea. Once it is ~80-90C you need a template that will bend it about 110' to get a 90' bend.

MadRhino said:

All sort of empty battery case are available on alibaba, from 5$ to 25$

Your 14s4p does fit in a standard dolphin case

Click to expand...

Thx, I didn't realize I could just drop this into a dolphin case. Just ordered a Hailong 2 case from a US based ebayer. Will be much nicer than trying to fab something together.

Yep. Big batteries or limited placement requirements are worth the trouble of building your own case, but when you only need a standard size and can fit it easily, it is cheaper and faster to just buy a common case.

I use bags, and do quite some mods to them for my lipos. At the end they cost much more than a standard case. I am working on a quick release CF case now, and realize that many are not spending that much for their whole ebike frame with integrated battery box. Well, at least it will be repeatable quickly for the next builds, and will be fitting almost any size L frame.

good job

PVC Pipe 4" x 10' $15 Has a wall thickness of 0.11" or 2.8mm for DR35
Heat Gun $20 8300N model 375°C / 540°C is like 750°F - 1000°F
NiChrome Wire - How to bend PVC https://www.youtube.com/watch?v=wVEf7PfuKxo
Just figure out the sidewalls and you are golden.
From the YT's I've seen, the PVC can get bumps in the surface without a smooth surface to clamp to.

markz said:

PVC Pipe 4" x 10' $15 Has a wall thickness of 0.11" or 2.8mm for DR35
Heat Gun $20 8300N model 375°C / 540°C is like 750°F - 1000°F
NiChrome Wire - How to bend PVC https://www.youtube.com/watch?v=wVEf7PfuKxo
Just figure out the sidewalls and you are golden.
From the YT's I've seen, the PVC can get bumps in the surface without a smooth surface to clamp to.

Click to expand...

Fantastic tip. I have a bunch of 4" pvc laying around. Love this idea... Will try it tomorrow.

The hailong 2 case did not work. A 14s4p battery in square plastic holders would not fit so I'm back to figuring out a DIY solution.

RichW_SC said:

markz said:

PVC Pipe 4" x 10' $15 Has a wall thickness of 0.11" or 2.8mm for DR35
Heat Gun $20 8300N model 375°C / 540°C is like 750°F - 1000°F
NiChrome Wire - How to bend PVC https://www.youtube.com/watch?v=wVEf7PfuKxo
Just figure out the sidewalls and you are golden.
From the YT's I've seen, the PVC can get bumps in the surface without a smooth surface to clamp to.

Click to expand...

Fantastic tip. I have a bunch of 4" pvc laying around. Love this idea... Will try it tomorrow.

The hailong 2 case did not work. A 14s4p battery in square plastic holders would not fit so I'm back to figuring out a DIY solution.

Click to expand...

Hailong only works with glued cells in a specific setup.

I have been pondering what to do with my new 18650-25R's there are lots of cases for $30usd but I suck at searches so haven't been able to find any dolphins besides BMS Battery.

I was thinking that aluminum sheet would be better, then adding a heavy plastic paint or coating of some kind.

I really want a professional looking battery case that fits in the triangle, easy to take off.
One that I can carry in with me to the Tim Hortons, Subway, McDonalds, YMCA Gym and people wouldnt know what it was, wouldnt even look at it twice.

I just think the PVC pipe would be too hard to make smooth because of the heat variances.

I get a little paranoid with my battery pack lately. I thought the distance I ride is 3km one way, but on Google Maps its like 4.12km one way, makes it 8.5km then tonight I did not charge up I just rode and it was 7km total in -5C (23F), 15.5km and yet my battery hit the controllers LVC of 31-32V. I go to check the voltage and its sunk way low not even close to 15V, more like 12V (10 minutes) for 5S6P half my pack in a split pack. I really have to be more careful. 36V 9Ah is 324Wh so should get 16km at 20km/Wh. Plus the cold. It does add up, if 36V9Ah is right, because it could very well be 12Ah36V gets me an added 5km. Then when I get home, I measured the DCDC output and I shorted it and frocked up the DCDC, so back to 39V instead of 41V. Amazon time and have to put on some epoxy between the leads on the pcb, and buy DCDC thats on separate sides in/out. No real point to this, just tired of range anxiety is all.

I am thinking perhaps I should have bought the PF 18650's with 2.9Ah instead of the 2.5Ah 25R's, but what I will do is have an emergency pack of 25R's of like 36V5Ah good for 50A, but emergency pack wont use much, just enough to get home. Good for 9km. Once the 18650's get above the 3Ah they become too expensive, plus FedEx likes to rip ya a new one with their extra fee's, NKON uses them. Only other choice is Unit Pack Power. Lots of good results from them from other members on ES. Price is about even, minus the work I have to do. 25R's are good. Stay with them, I bought 85 so 20Ah in 36V, good for 36km. Don't want to leave them in the cold thats for sure. Start the box building process this week I guess. Aluminum sheets.

After scouring amazon for a plastic container of the right size i did find this. I did order it to see if it would work. Would likely do a magnet/velcro attachment to the bike of some sort. Just need it semi permanent as I will be charging in my garage.


https://www.amazon.com/gp/product/B00A17UK48/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1