Hi. Okay, this is a spin-off of Lars` thread on cooling Tesla packs.
The last post brought up heating the packs using the heaters from EV West, which I am also going to use. I have a Tesla water pump too, but cannot make it spin - it looks like an AC motor (5 wires - 3 phases, plus encoder?). I have bought some pumps for circulating hot water for solar-heating applications, but will instead try the EV West pumps from a Smart Car, as they are not diaphragm pumps, probably quieter, and a good price. We will see how hard they are to mount - on order.
I had an Engineer calculate that to heat 5 modules by 10C in 10 minutes would take about 900Watts. Two of these heaters will be less than that, and I now have six modules, but I still like them.
I'm going to use two separate loops too - one for front and one for the back, which means quite a 12V current draw, so unless I think of something clever, will need a larger DC-DC converter (more $$$....).
One idea I'd like some feedback on is to keep all of the batteries at the same temperature by circulating fluid through them slowly. My thinking is: over time it is temperature differences which will cause them to drift. I am not a fan of top-balancing, but will monitor everything using an Orion - so I could top-balance if I want, or found I needed to.
We have a nice design for the battery boxes going. After building the front box out of metal using rails to support, we got the idea to use slots for the back - in 1/2" PVC. This is nice material to work with, as holes are easy to make, it takes a thread very well or you can use inserts if more strength is needed. We cut slots for the battery rails using a table-saw, and joining pieces was quite easy by cutting slots and using 1/8 x 1/2" aluminum bar (see sketch). All is tied-together with plastic banding - metal would be better, but the tooling is about $1,500 and that kind of strength is not needed. Then it sits in a steel frame. We built a box for three bricks, which weighs 37lbs and cost about $150. Half that price was the 1/2" clear acrylic top. If you screw something up, you only need to re-make that piece, not scrap the whole box. I'll attach some pics.
In the end we went with continuous sides rather than the modular idea, but the slots as shown worked perfectly.
It would be nice to share ideas on cooling/heating, bulkhead connections (BMS anyone?) and...?
We will be receiving our first 3D printed manifold today - only $80 - and yes, we will share.
The last post brought up heating the packs using the heaters from EV West, which I am also going to use. I have a Tesla water pump too, but cannot make it spin - it looks like an AC motor (5 wires - 3 phases, plus encoder?). I have bought some pumps for circulating hot water for solar-heating applications, but will instead try the EV West pumps from a Smart Car, as they are not diaphragm pumps, probably quieter, and a good price. We will see how hard they are to mount - on order.
I had an Engineer calculate that to heat 5 modules by 10C in 10 minutes would take about 900Watts. Two of these heaters will be less than that, and I now have six modules, but I still like them.
I'm going to use two separate loops too - one for front and one for the back, which means quite a 12V current draw, so unless I think of something clever, will need a larger DC-DC converter (more $$$....).
One idea I'd like some feedback on is to keep all of the batteries at the same temperature by circulating fluid through them slowly. My thinking is: over time it is temperature differences which will cause them to drift. I am not a fan of top-balancing, but will monitor everything using an Orion - so I could top-balance if I want, or found I needed to.
We have a nice design for the battery boxes going. After building the front box out of metal using rails to support, we got the idea to use slots for the back - in 1/2" PVC. This is nice material to work with, as holes are easy to make, it takes a thread very well or you can use inserts if more strength is needed. We cut slots for the battery rails using a table-saw, and joining pieces was quite easy by cutting slots and using 1/8 x 1/2" aluminum bar (see sketch). All is tied-together with plastic banding - metal would be better, but the tooling is about $1,500 and that kind of strength is not needed. Then it sits in a steel frame. We built a box for three bricks, which weighs 37lbs and cost about $150. Half that price was the 1/2" clear acrylic top. If you screw something up, you only need to re-make that piece, not scrap the whole box. I'll attach some pics.
In the end we went with continuous sides rather than the modular idea, but the slots as shown worked perfectly.
It would be nice to share ideas on cooling/heating, bulkhead connections (BMS anyone?) and...?
We will be receiving our first 3D printed manifold today - only $80 - and yes, we will share.