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To
do this, we decide to use 40 mil sheet PVC.
This
is available from Home Depot where it is used as a shower liner.
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Each
battery tab looks like this before we start. We decide against tab
welding since we want to retan the ability to easily switch out
cells.
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|
| We
plan to connect the cells by pressing the tab faces together using
two pieces of 1/16 brass sheet held by two screws. To save space,
we trim down the tabs to a little wider than 3/4 inch. |
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This
still gives us a contact area of 3 square inches. The tab material
is thin enough that scissors work fine. Then using a Roper Whitney
No. 5 Jr Hand Punch, we make two 3/16 inch holes.
|
|
| We
have been warned by Kokam to take care when handling the cell. Do
not bend it. Do not put undue strain on the tabs. |
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To
keep our PVC strips in place, we use a little mild glue.
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To
get the air gap we want, we use 3 layers of 40 mil PVC.
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 |
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The
next cell goes on with the opposite face up. This puts the positive
tab of the first cell to the negative tab of the second cell.
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Then
line up the holes on the two tabs.
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We
put a dab of the weakest 'thread lock' on each screw. The black
14 gauge wire is for the BMS system.
|
 |
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Notice
that the PVC strip also serves to insulate the tabs from the batteries
above and below.
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It
is important to be careful that the PVC does not slip out and the
tabs short. These are powerful batteries!
|
 |
| Depending
on where the battery stack will sit, the air flow will be different. |
 |
|
This
set up allows a straight thru air flow.
|
 |
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Here
is a side view of a 'hybrid' air flow stack. The bottom section
gets air from this side. The top cells get air from the front (left
side in this picture).
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 |
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Here
is a 16 cell stack ready to be put in the car.
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| |
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