Battery Pack Building - 2 different styles

[Therrin]

After a bit of discussion with Joanne, and after my initial several trips' use of the "Jihad-style" battery pack I constructed from PVC pipe fittings; I finally got my order from HobbyKing through HongKong, after it sat in customs for almost 2 weeks.

I decided to deconstruct the outside of the Jihad-style pack, and rewire it's parallel connectors, as well as remove its molex connector and replace with more substantial wire and XT60 connectors.



After that I simply heat shrunk a cover over the whole thing, to insulate my exposed ends, which were originally used to clip the charger clamps onto for charging (which worked peachy at the time). Now I charge through the XT60 connector.
The nice thing about this pack, with each cell in a Sch40 pvc jacket, they are near waterproof, and are very resistant to impacts. Though it is considerably bulkier.



The second pack I used started with the plastic 2 cell 18650 holder which has built in protection circuit, configured 1S2P.
I removed the existing shrink wrap on the batteries, and replaced it with a slightly thicker Turnigy heat shrink that is clear. This allows not only some protection to the cells, but also allows me to see throw the wrap if the casing is damaged at all.



Next I wrapped the whole pack with super88 electrical tape, then placed a small piece of plastic over the exposed cell section then wrapped again. Seen partially complete in this photo



Following this, I heat shrunk a first layer around the pack. Then I dunked the whole assembly in black plasti-dip once, let it dry for a few hours, then dunked it again for a second coat.


Finished pic. This pack has had its cells shrinkwrapped, inserted in the holder w/ protection circuit, wrapped, shielded, wrapped, srinkwrapped, dipped, dipped, and shrink wrapped.


Now I just need to make a few with 3 parallel and 4 parallel.
And, I only just saw how Joanne's pack has the connector shrinkwrapped from the head down the length of the wires, which is probably a good idea.

I also added an XT60 connector to the wire coming from my modified Fenix HP20, and left the wire long enough to loop back on itself and ziptie on each end for strain relief. If something is snagged it will pull out a ways.
Thinking of either routing the wires inside the helmet at this point, or taping them down.

[Joanne]

Really nice job on your new battery packs! The size and weight will be ideal on your helmet. After using a large capacity rechargeable battery pack I was hooked! I really like not having to mess with primary batteries. I've even moved to a 18650 based handheld light for the same reason.

Without having to buy fresh batteries all the time, the "cost of ownership" will continue to diminish over time. Even the initial investment in a hobby charger and batteries isn't that expensive compared to the cost of our other exploring gear. (helmets, headlamps, harnesses, ropes, ascenders, carabiners, and such)

Chat later!
Joanne

[Therrin]

I'll recoop the cost of the charger itself in one 3 day exploring trip, not having to use primaries.

And ever since I turned from primaries in handhelds a couple years ago to 18650's or 16340's (rcr123's), I haven't looked back. I tend to scoff at my lights that run on primaries now.

I'm finding out now how some Li-ions are different from others, and which ones are best for certain things and produce the best light output. I'm going ANOTHER level deeper, into the MADNESS!

[Stuart]

Nice work! I'm going to have to rebuild my packs again here someday. They stopped making the model we use.

[Therrin]

So, I've converted all of my headlamps that have external battery packs to have connectors on both the battery pack side and the lamp side, so I can swap packs out of them.
They can use either the Li-ion packs, or their original 4xAA packs with NiMh rechargeables.

I even fried the LED in one already. I was using it to discharge a pack, to check for runtime; but I left it pointing at the ceiling in a room with no moving air and it 'cooked' the LED. It now gives off a blue-tinged light and only puts out about 1/3rd to 1/2 output. But it does still put out useable light, so I still have it for a backup lamp at the moment. It's one of the Fenix HP20's. Haven't figured out how to mod the LED on it yet.

Also... with the HP20's, when you cut off the wire-controller and the existing battery pack, you lose the switching and regulation circuitry. So it's just "on full" or "off". Which is fine with me on that model. The problem though, with no circuitry, you're giving it less voltage than it was intended to get (3.7 to 4.2 instead of 6), so I *think* it's pulling more amperage. (correct me here if I'm wrong)

Still enjoying working on the lights and packs. We'll see what comes of it.

Doing the learning curve on using the NiMh batteries. Maybe I'll post a thread on it and anyone else who uses them can talk it over with me.

[Joanne]

I'm looking forward to seeing your new battery packes this weekend. We will give them a workout for certain. I have thought about modding my Apex Pro lights to use my rechargeable packs but just haven't dug in and done so yet. Now I keep them as my backup and "loaner" lights.

It would be interesting to see the difference in amp draw of the lights at the lower voltage. I don't know if it simply draws more amps, or if it draws the same amps at a lower voltage resulting in less light. We should be able to hook up an amp meter and find out. My DVM should work on that.

I'll be heading over to the airport in a few minutes to pick up Speedy. See you Saturday!

Joanne

So, I've converted all of my headlamps that have external battery packs to have connectors on both the battery pack side and the lamp side, so I can swap packs out of them.
They can use either the Li-ion packs, or their original 4xAA packs with NiMh rechargeables.

I even fried the LED in one already. I was using it to discharge a pack, to check for runtime; but I left it pointing at the ceiling in a room with no moving air and it 'cooked' the LED. It now gives off a blue-tinged light and only puts out about 1/3rd to 1/2 output. But it does still put out useable light, so I still have it for a backup lamp at the moment. It's one of the Fenix HP20's. Haven't figured out how to mod the LED on it yet.

Also... with the HP20's, when you cut off the wire-controller and the existing battery pack, you lose the switching and regulation circuitry. So it's just "on full" or "off". Which is fine with me on that model. The problem though, with no circuitry, you're giving it less voltage than it was intended to get (3.7 to 4.2 instead of 6), so I *think* it's pulling more amperage. (correct me here if I'm wrong)

Still enjoying working on the lights and packs. We'll see what comes of it.

Doing the learning curve on using the NiMh batteries. Maybe I'll post a thread on it and anyone else who uses them can talk it over with me.

[Therrin]

Awesome! The days are counting down. I actually hit up two little mines near the town of Julian out here, yesterday. Trying to limber up a little and make sure I'll be ready for next week.

I've tried doing amps on my Fluke but I always get this insanely low reading. I think a fuse is bad but they're internal and I gotta pull it apart to see about replacing them.

That'd be best though, with the lights it's really difficult to tell between two levels of light with just your eyes. Or with just my eyes anyway.

Sadly, after talking to Speedy, I think you two and I have our connectors set up in reverse. I got my charger with the plug oriented the way it was the way it showed up, and just started making packs with the opposite connector on them, and put the same connector on the light-end as the charger had. Speedy for some reason uses the other end on his charger, and said he had you swap the end on your charger for the other one as well. I think he made an adapter so we can share around.