diy solar

diy solar

4S 272/280ah enclosure suggestion

And more...

Notice how I put the vent holes inside the natural hood that's molded into the back. This should provide a good weather shield to keep any rain out of the box. I was going to drill a bigger hole and then decided that several smaller holes would keep mice out. Not sure if the holes will help with cooling, but I was worried that if the cells vented for any reason, the case is so tight that could rupture violently without some vents. I needed a right angle adapter to drill the holes inside the box.

I used some crafting clay to check the vertical clearance (again, 4mm of foam underneath and 16mm studs) and found that it's mighty tight at only 3mm clearance to the lid. Should be enough...

-uberpixel

Photo Mar 21, 5 49 37 PM.jpgPhoto Mar 21, 5 49 46 PM.jpgPhoto Mar 21, 5 54 04 PM.jpegPhoto Mar 21, 5 54 14 PM.jpegPhoto Mar 21, 6 04 58 PM.jpgPhoto Mar 21, 6 05 07 PM.jpgPhoto Mar 21, 6 05 49 PM.jpgPhoto Mar 21, 6 07 44 PM.jpeg
 
One of the cool things about these cases is that they have a bunch of molded in holes for adding interior panels. I took advantage of those holes to mount the aluminum angle that holds the BMS in place.

I've attached (to this post) a PDF of the 1:1 template I used to cut out the part - set your printer to custom scale 100% and then cutout and stitch the pieces together (it's too big for an 8x5x11" sheet). For shaping the aluminum I stuck the pattern to the aluminum with contact cement and then used a stationary sanding wheel (I use a 10" disk on my table saw) and a scroll saw. I think I used #6 x 3/8" sheet metal screws to attach to the box and M4 (I think?) machine screws to attach the BMS to the angle (taking advantage of the threaded standoffs already on the BMS).

You can also see how I added the optional on/off hardware switch. In my case I had to solder a header onto the BMS, but some are sold with the header already. As I suspected, the board worked as expected with the addition of the header and switch - they just went cheap on mine and omitted the header for some reason.

-uberpixel

Photo Mar 21, 6 22 37 PM.jpgPhoto Mar 21, 6 22 41 PM.jpgPhoto Mar 21, 6 22 47 PM.jpgPhoto Mar 21, 6 55 03 PM.jpgPhoto Mar 16, 6 49 40 PM.jpgPhoto Mar 16, 6 49 56 PM.jpgPhoto Mar 16, 7 01 20 PM.jpgPhoto Mar 16, 7 24 22 PM.jpeg
 

Attachments

  • DWG_Battery_Plate_final.pdf
    24.5 KB · Views: 25
Last edited:
Finally, I packed another row of foam around the top of the cells to keep them from rocking around - including putting some foam between the aluminum angle and the cells. I considered adding a more rigid bumper to ensure there wouldn't be any metal on metal contact, but this seems pretty secure.

The Bluetooth module is stuck to the lid with VHB for the time being, but I may make a plywood tab that's screwed into the lid to keep it secure.

All in, it weighs 54.6 lbs. I have it set up on an endurance test with my cooler to see how many days of cold beer I can get out of it...

-uberpixel

Photo Mar 21, 6 54 55 PM.jpegPhoto Mar 21, 6 55 00 PM.jpgPhoto Mar 21, 6 55 05 PM.jpgPhoto Mar 20, 7 38 13 PM.jpegPhoto Mar 21, 6 55 07 PM.jpgPhoto Mar 21, 6 59 47 PM.jpegPhoto Mar 22, 8 08 50 PM.jpgPhoto Mar 22, 8 09 03 PM.jpg
 
I should add, this is my first battery build. I'm open to criticism and suggestions and by no means warrant or endorse my work as correct or proven... But, hopefully somebody else finds some part of this useful.

Please share your questions or build pictures if you make one!

-uberpixel
 
Thanks for those pictures this is going to save me a lot of trouble stumbling through this project. I see you have the iceCo freezer I thought about that it looks like one of the better Chinese Brands, but then I finally said oh what the hell and bought the National Luna dual control. $1300 but you get what you pay for.
Previously I had a whynter that lasted 3 yrs and then after that a costway which was a real piece of dung.
 
Finally, I packed another row of foam around the top of the cells to keep them from rocking around - including putting some foam between the aluminum angle and the cells. I considered adding a more rigid bumper to ensure there wouldn't be any metal on metal contact, but this seems pretty secure.

The Bluetooth module is stuck to the lid with VHB for the time being, but I may make a plywood tab that's screwed into the lid to keep it secure.

All in, it weighs 54.6 lbs. I have it set up on an endurance test with my cooler to see how many days of cold beer I can get out of it...

-uberpixel

View attachment 42452View attachment 42453View attachment 42454View attachment 42459View attachment 42455View attachment 42456View attachment 42457View attachment 42458
Dude this is awesome and love the ICECO I have been using their fridges for good while. I have one in my car at all times freezer and fridge. So I would like to hear some test how long that battery pack powers that fridge? I ran mine with no charge over a week. that is with one side 0F and other at around 34F.
 
Dude this is awesome and love the ICECO I have been using their fridges for good while. I have one in my car at all times freezer and fridge. So I would like to hear some test how long that battery pack powers that fridge? I ran mine with no charge over a week. that is with one side 0F and other at around 34F.
Dont know about you but I LOVE the dual temp/control units and dont know how I got by with the freezer only model. There really wasnt an effective way to keep things at different temps.
National Luna uses dual controls that seem to pipe refrigerant to coils individually to each side. I had considered engel, but they just use a fan between compartments.
The Iceco that has dual controls, how does it distribute the temp?
 
Dont know about you but I LOVE the dual temp/control units and dont know how I got by with the freezer only model. There really wasnt an effective way to keep things at different temps.
National Luna uses dual controls that seem to pipe refrigerant to coils individually to each side. I had considered engel, but they just use a fan between compartments.
The Iceco that has dual controls, how does it distribute the temp?
I have the VL60 in the back of my car and its keeps temps really well. The smaller GO20 I also had and was ok just felt it wasn't insulated enough for what I needed.
But as to how it distributes the temp think its done via a valve that distributes between the "Zones".
 
I should add, this is my first battery build. I'm open to criticism and suggestions and by no means warrant or endorse my work as correct or proven... But, hopefully somebody else finds some part of this useful.

Please share your questions or build pictures if you make one!

-uberpixel
Looks really good, nice and compact.

In the picture, it looks like the bms might take the force of the battery shifting in that direction as the foam is compresses. In a mobile trailer, the foam will be acting as a shock absorber and the battery will the moving around a bit even with foam trying to hold it in place. You might consider adding some wood strips or something between the battery and box on the BMS side that limits the movement. This would ensure that the wood constrains the battery movement rather than the BMS. You might already have something under the foam doing that, but just a suggestion. Those BMS's are pretty sturdy, but they shouldn't be your "bump stop" for battery movement.
 
Looks really good, nice and compact.

In the picture, it looks like the bms might take the force of the battery shifting in that direction as the foam is compresses. In a mobile trailer, the foam will be acting as a shock absorber and the battery will the moving around a bit even with foam trying to hold it in place. You might consider adding some wood strips or something between the battery and box on the BMS side that limits the movement. This would ensure that the wood constrains the battery movement rather than the BMS. You might already have something under the foam doing that, but just a suggestion. Those BMS's are pretty sturdy, but they shouldn't be your "bump stop" for battery movement.
That’s a valid concern and something I have been thinking about. It’s hard to tell from the pictures, but there’s nothing but airspace (about 1/2”) between the actual BMS and the cells. I placed some foam between the aluminum angle “rail” and the cells to keep them from rocking into the BMS, but as I mentioned previously, some sort of rigid bump stop mounted to the rail and in contact with the cells would ensure that there isn’t physical contact between BMS and the cells.

With my current layout of foam, I have a continuous band on 3 sides and some smaller blocks on the BMS side, so the only direction the cells want to move is toward the BMS (unfortunately), but it’s tough to tell if it’s really a problem or not.

The box itself will be mounted “the long way” on my trailer tongue so any braking or inputs will not put the BMS in danger, but side inputs could be a concern.

And for those distracted by my cooler picture, it’s a new Iceco VL45 single zone. So I can’t really attest to its performance or quality. I have it set to 36F on “min”. Endurance test is on day 3 and I’ve been opening it up randomly to simulate actual use. The beer and cooler was warm at the start so it ran for a bit to get down to temp. I’ll let you know how far it will go.

-uberpixel
 
Last edited:
With my current layout of foam, I have a continuous band on 3 sides and some smaller blocks on the BMS side, so the only direction the cells want to move is toward the BMS (unfortunately), but it’s tough to tell if it’s really a problem or not.
Probably a low probability problem, but all it takes is one good knock and road forces/dynamics are hard to anticipate. Maybe a couple wood or plastic strips just a bit thicker than the BMS taped to that side of the box or cells. If there wasn't that metal strip across the top, you could count on the battery box to flex/give on impact at bit, but I think you could end up with all the force of those cells hitting that thin metal strip with the BMS as the "meat" in the sandwich.
 
Probably a low probability problem, but all it takes is one good knock and road forces/dynamics are hard to anticipate. Maybe a couple wood or plastic strips just a bit thicker than the BMS taped to that side of the box or cells. If there wasn't that metal strip across the top, you could count on the battery box to flex/give on impact at bit, but I think you could end up with all the force of those cells hitting that thin metal strip with the BMS as the "meat" in the sandwich.
I had actually already taped an extra layer of cutting board plastic to this side of the cells as an added buffer. Just didn’t mention in my previous build notes. I appreciate that you’ve identified one of the potential failure points that I was concerned about. Confirms my thinking...

-uberpixel

6E43023E-1692-4433-B417-1BD053A3DC44.jpeg
 
I’ve built a number of batteries and none of them are half as nice ?

Well done!
 
You mentioned thin cutting board between the cells, do you know the actual thickness?
Was at wally world tonight they had some white 8.5 x 11 cutting boards guesstimate 1/8" for .88 cents i bought all 5. Still need more.
 
You mentioned thin cutting board between the cells, do you know the actual thickness?
Was at wally world tonight they had some white 8.5 x 11 cutting boards guesstimate 1/8" for .88 cents i bought all 5. Still need more.
This is what I used [link]

They are quite thin at only 0.02” or 0.5mm.

-uberpixel
 
I happened to contact this company (seahorse) and they offered me a 15% discount code and said share it with the group. So if you place an order for this use code FIFTEEN.
 
I happened to contact this company (seahorse) and they offered me a 15% discount code and said share it with the group. So if you place an order for this use code FIFTEEN.
Nice work. I guess it never hurts to ask! I'm definitely impressed with the case. VERY sturdy and well built. Maybe I'll reach out to them and see if they'll give me a deal on some lock cores for the latches...

-uberpixel
 
Back
Top