Some mods/APV's are critical of the length of the battery. When I purchased my VV Gripper it was clear that the Panasonic CGR18650CH that I had would not fit well. Why? The battery had an large diameter button added to it by the wholesaler. this button made it too long for my VV Gripper. So I removed the button, here's how...
What's Needed:
-Knife
-Heat source - Hair Blow drier, Heat gun, Mini Torch with hot air attachment.
-PVC heat shrink - 32mm flat, 20mm diameter.
Optional:
-Emery Board, Sandpaper, or Dremel with small grinding stone.
-Safety First
DO NOT attempt this if you are not sure of what you are doing. I will give as much information as possible, but there is no replacement for a clear understanding of the dangers involved with lithium batteries. You will be working with an unshielded battery where the positive and negative poles are separated by less than .5mm. One slip of a conductive object (knife) and you have created a dangerous short. Read the entire procedure first (or multiple times) and proceed with caution. DO NOT ATTEMPT THIS WITH batteries THAT HAVE A PROTECTION CIRCUIT. PROTECTED BATTERIES ARE LONGER BECAUSE THEY REQUIRE THE ADDED PROTECTION CIRCUIT. WITHOUT PROPER KNOWLEDGE, YOU WILL DAMAGE THE PROTECTION CIRCUIT AND PUT YOURSELF AND OTHERS IN DANGER.
First is to remove the old jacket. Do not let the knife contact the top (positive end) of the battery. Start about 2-4mm from the top. Keep the blade on the side of the battery and cut towards the bottom (negative end). You will have this:
Button pulled up showing the metal strip.
The entire case is the negative pole. The positive pole is held in place by a non-conductive separator and then the case is crimped above and below the separator. The thin white disc is all that separates the added positive button from negative. This is why you need to start 2-4mm below the top of the battery (near the grove that is created when the battery is crimped) to prevent the knife from contacting the added positive button and the negative case.
Green=Negative
Red=Positive
Next is to remove the button. It is usually held on by tiny spot welds. Just pull the button off, the metal strip will pull away breaking the spot welds. You will want to make sure that there in no small pieces of the strip that remained on the spot weld. You could use an emery board or piece of sandpaper to remove the little slivers. I used a dremel with a small grinding stone. Just make sure that whatever you use is NON-CONDUCTIVE. Remove the white disc to prevent damage while sanding or grinding, you will need to reuse this to finish the job. When you are ready to continue, the battery should look like this:
Now you are ready for the heat shrink. For an 18650, I found that 72mm worked best. Insert battery and center, leaving equal overhang on each end.
Now you are ready to shrink. I first tried a pencil torch with a hot air attachment (no exposed flame) and it worked, but was difficult to control hot spots that would thin out the heat shrink and create holes. I would not recommend anything with an open flame, PVC heat shrink is quite sensitive. A variable temp heat gun would work best, but I had to revert to next best....hair dryer with a flat diffuser nozzle.
Working from the center out, shrink until the entire length it done saving the ends for last. It may take a few tries, so make sure that you order enough heat shrink for trial and error. It took me 4 fails to get the first success. The subsequent successes came much easier. When you succeed, the battery should have a good overlap around the two ends.
The finished product:
What's Needed:
-Knife
-Heat source - Hair Blow drier, Heat gun, Mini Torch with hot air attachment.
-PVC heat shrink - 32mm flat, 20mm diameter.
Optional:
-Emery Board, Sandpaper, or Dremel with small grinding stone.
-Safety First
DO NOT attempt this if you are not sure of what you are doing. I will give as much information as possible, but there is no replacement for a clear understanding of the dangers involved with lithium batteries. You will be working with an unshielded battery where the positive and negative poles are separated by less than .5mm. One slip of a conductive object (knife) and you have created a dangerous short. Read the entire procedure first (or multiple times) and proceed with caution. DO NOT ATTEMPT THIS WITH batteries THAT HAVE A PROTECTION CIRCUIT. PROTECTED BATTERIES ARE LONGER BECAUSE THEY REQUIRE THE ADDED PROTECTION CIRCUIT. WITHOUT PROPER KNOWLEDGE, YOU WILL DAMAGE THE PROTECTION CIRCUIT AND PUT YOURSELF AND OTHERS IN DANGER.
First is to remove the old jacket. Do not let the knife contact the top (positive end) of the battery. Start about 2-4mm from the top. Keep the blade on the side of the battery and cut towards the bottom (negative end). You will have this:
Button pulled up showing the metal strip.
The entire case is the negative pole. The positive pole is held in place by a non-conductive separator and then the case is crimped above and below the separator. The thin white disc is all that separates the added positive button from negative. This is why you need to start 2-4mm below the top of the battery (near the grove that is created when the battery is crimped) to prevent the knife from contacting the added positive button and the negative case.
Green=Negative
Red=Positive
Next is to remove the button. It is usually held on by tiny spot welds. Just pull the button off, the metal strip will pull away breaking the spot welds. You will want to make sure that there in no small pieces of the strip that remained on the spot weld. You could use an emery board or piece of sandpaper to remove the little slivers. I used a dremel with a small grinding stone. Just make sure that whatever you use is NON-CONDUCTIVE. Remove the white disc to prevent damage while sanding or grinding, you will need to reuse this to finish the job. When you are ready to continue, the battery should look like this:
Now you are ready for the heat shrink. For an 18650, I found that 72mm worked best. Insert battery and center, leaving equal overhang on each end.
Now you are ready to shrink. I first tried a pencil torch with a hot air attachment (no exposed flame) and it worked, but was difficult to control hot spots that would thin out the heat shrink and create holes. I would not recommend anything with an open flame, PVC heat shrink is quite sensitive. A variable temp heat gun would work best, but I had to revert to next best....hair dryer with a flat diffuser nozzle.
Working from the center out, shrink until the entire length it done saving the ends for last. It may take a few tries, so make sure that you order enough heat shrink for trial and error. It took me 4 fails to get the first success. The subsequent successes came much easier. When you succeed, the battery should have a good overlap around the two ends.
The finished product:
