hardtop
New Member
It was 32F this morning and I used a chinese diesel heater to warm the pack. The beauty is it warms my tent too. The black/aluminum tube is the heat output.
First time DIY case
- Thread starter hardtop
- Start date
hardtop
New Member
Great question, I wonder that myself. The cells seem to be working fine like that. I need to add a BMS but for now I'm not too worried. Problably some rejects from China, they stuck me with them and profited handsomely.
yabert
Solar Enthusiast
Add a shrink tube or add 2-3 layers of electric tape over the rods will secure this.This is a pic showing the rod clearance:
Marinepower
Solar Enthusiast
- Joined
- Apr 24, 2020
- Messages
- 224
Yes I agree,
i tried to make a compression fitting out of even thicker and harder plastics and it just tends to bend, which places all the pressure on the corners of the cells and not in the middle where you actually need the support.
I suggest running the stainless rods through some cheap aluminium angle iron on the outside of the plastic upright boards to support the bending tendency of the plastic.
Angle iron example:
ALLSTAR PERFORMANCE Alum Angle 1 x 1 x 1/8 4ft P/N - ALL22254-4 | eBay
Find many great new & used options and get the best deals for ALLSTAR PERFORMANCE Alum Angle 1 x 1 x 1/8 4ft P/N - ALL22254-4 at the best online prices at eBay! Free shipping for many products!
www.ebay.ca
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That method has done well for me my whole life.
hardtop
New Member
The angle iron could also serve as a handle to pickup the pack.Yes I agree,
i tried to make a compression fitting out of even thicker and harder plastics and it just tends to bend, which places all the pressure on the corners of the cells and not in the middle where you actually need the support.
I suggest running the stainless rods through some cheap aluminium angle iron on the outside of the plastic upright boards to support the bending tendency of the plastic.
Angle iron example:
ALLSTAR PERFORMANCE Alum Angle 1 x 1 x 1/8 4ft P/N - ALL22254-4 | eBay
Find many great new & used options and get the best deals for ALLSTAR PERFORMANCE Alum Angle 1 x 1 x 1/8 4ft P/N - ALL22254-4 at the best online prices at eBay! Free shipping for many products!www.ebay.ca
hardtop
New Member
I looked at angle iron today and started to think maybe I should use proper material that doesn't need reinforcement. But then I might end up with steel plates 1/2" thick and increase what is already 50 pounds by 20 pounds.
New project, new tool. Think of all the money we are saving.
Marinepower
Solar Enthusiast
- Joined
- Apr 24, 2020
- Messages
- 224
I use 1/4 aluminium plates for end plate compression , mostly because I am very space constrained. I would stay away from steel or AL plates however as they are electrically conductive, so a potential shorting hazard.....
hardtop
New Member
Based on feedback from this community I covered the stainless allthread and used plex tubing. It wasn't a simple process because I bought 1/4" inner diameter tube and the 1/4" rod didn't fit through lol. I made it work by running a cut down the pipe and that allowed enough flex to fit the rod through. Ideally I would use proper size but I didn't want to go to the store again and waste the tubing.
Next suggestion was to put something between the cells and for that I'm going to buy the acrylic sheets aka plexi glass and put that between the cells. I inspected in-between each cell and there were some abrasions but nothing even remotely bad.
The blue plastic has tweaked some and I was looking at other materials to use in conjunction with the threaded rods to compress the cells together instead of the 1/2" cutting board plastic. Wood tweaks some too and guys have springs along with the wood so to me that says flexing is fine. So why not let the plastic flex? Do the cells need to be flat, if not why are the corners rounded? I'm curious to hear from those who mentioned the plastic being a problem because of flex.
The local hw store had steel plates but I don't have tools to cut it to size and drill holes. That really would be the best option because the steel won't bend as easily, if there is payoff for preventing a bend. Is there a benefit to preventing the end plates of the battery box from flexing? I checked out some options for wood and there was 3/4" maple plywood which sounds pretty strong, but if the plywood is going to flex then does it make sense to spend $45 when I could just let the plastic flex?
This 1/8" sheet of plastic is starting to look like a good piece for the top where two grooves could be cut in the blue pieces to slide the black sheet over the cells. When maintenance is needed, the sheet could be pulled out to provide access to the cell terminals. It would also protect from small pebbles getting between the cells when maintence is finished. I had one pebble fall down in there between the cells that needed to be removed because when the pack swells it would pinch the pebble.
Next suggestion was to put something between the cells and for that I'm going to buy the acrylic sheets aka plexi glass and put that between the cells. I inspected in-between each cell and there were some abrasions but nothing even remotely bad.
The blue plastic has tweaked some and I was looking at other materials to use in conjunction with the threaded rods to compress the cells together instead of the 1/2" cutting board plastic. Wood tweaks some too and guys have springs along with the wood so to me that says flexing is fine. So why not let the plastic flex? Do the cells need to be flat, if not why are the corners rounded? I'm curious to hear from those who mentioned the plastic being a problem because of flex.
The local hw store had steel plates but I don't have tools to cut it to size and drill holes. That really would be the best option because the steel won't bend as easily, if there is payoff for preventing a bend. Is there a benefit to preventing the end plates of the battery box from flexing? I checked out some options for wood and there was 3/4" maple plywood which sounds pretty strong, but if the plywood is going to flex then does it make sense to spend $45 when I could just let the plastic flex?
This 1/8" sheet of plastic is starting to look like a good piece for the top where two grooves could be cut in the blue pieces to slide the black sheet over the cells. When maintenance is needed, the sheet could be pulled out to provide access to the cell terminals. It would also protect from small pebbles getting between the cells when maintence is finished. I had one pebble fall down in there between the cells that needed to be removed because when the pack swells it would pinch the pebble.
Last edited:
hardtop
New Member
I wanted to share my case revisions since the beginning of the year. I followed a lot of advice here except the material that goes in between the cells. I skipped that part but may do it in the future as well as using wood for the next box or maybe steel from a tank lol.
The lid part of the case is going to hold 4 12v 15amp cigarette lighter sockets for things like my Engel refrigerator, WeBoost cell amp and to adapt USB charging.
All the 12v USB chargers that are not cigarette lighter adapters (or 120v) are low amp, like 2.4 and that isn't enough with today's mobile device chipsets. I looked all over. My oneplus phone needs about 7 amps, pixel tablet needs way more than 2.4 amps so the cigarette lighter adapters will provide that high output.
I found junctions at West Marine for 4 sockets to connect to and I'm waiting for the remaining cigarette lighter sockets and cables. The other improvement is to connect my charger VIA anderson connector and also connect the inverter the same way.
But I fugged up and didn't get the cable lengths right on the device end. So I bought pins for the anderson connector to adapt some of the stiff wire I have. I don't think I need to spend on soft wire because the end points are strong, unlike the BMS where I already cracked it trying to tweak wire with it so that was a $100 mistake and BMS #4 lol.
I've been thinking about having two anderson connections so that I could have both the charger and inverter on at the same time, but those cables I ordered are thick and there isn't a whole lot of real estate in the tight places to connect them. They are 0 awg cables and I'm not sure about room for two connections but I think it would be a good future improvment.
The lid part of the case is going to hold 4 12v 15amp cigarette lighter sockets for things like my Engel refrigerator, WeBoost cell amp and to adapt USB charging.
All the 12v USB chargers that are not cigarette lighter adapters (or 120v) are low amp, like 2.4 and that isn't enough with today's mobile device chipsets. I looked all over. My oneplus phone needs about 7 amps, pixel tablet needs way more than 2.4 amps so the cigarette lighter adapters will provide that high output.
I found junctions at West Marine for 4 sockets to connect to and I'm waiting for the remaining cigarette lighter sockets and cables. The other improvement is to connect my charger VIA anderson connector and also connect the inverter the same way.
But I fugged up and didn't get the cable lengths right on the device end. So I bought pins for the anderson connector to adapt some of the stiff wire I have. I don't think I need to spend on soft wire because the end points are strong, unlike the BMS where I already cracked it trying to tweak wire with it so that was a $100 mistake and BMS #4 lol.
I've been thinking about having two anderson connections so that I could have both the charger and inverter on at the same time, but those cables I ordered are thick and there isn't a whole lot of real estate in the tight places to connect them. They are 0 awg cables and I'm not sure about room for two connections but I think it would be a good future improvment.
hardtop
New Member
hardtop
New Member
I'm looking to wire up and mount the 12v socket adapters. It has 4 AWG leads that will connect to the pos. and neg. junctions. The power sockets use 10-12 AWG wire and I'm aiming for at least 15 AMP draw but if something needs more I have a 30 AMP fuse.
I'm pretty sure my gauges are all out of line but, my issue now is connecting the power leads to the junctions. I tried a nut and bolt to fasten it, but the metal plating (chrome color) is slick and it seems there should be a better way. Like a lock washer and maybe some locktight?
The nut and bolt used is sitting in the pic near the negative terminal. Its small diameter because the larger diameter bolts are also longer and that pushes the terminal away from the plastic which I'd like to limit. Any ideas on how to connect the leads to the junctions?
I'm pretty sure my gauges are all out of line but, my issue now is connecting the power leads to the junctions. I tried a nut and bolt to fasten it, but the metal plating (chrome color) is slick and it seems there should be a better way. Like a lock washer and maybe some locktight?
The nut and bolt used is sitting in the pic near the negative terminal. Its small diameter because the larger diameter bolts are also longer and that pushes the terminal away from the plastic which I'd like to limit. Any ideas on how to connect the leads to the junctions?
