18months back I wrote about how I was collecting discarded disposable vapes (electronic cigarettes) and recovering the perfectly serviceable rechargable LiPo cells they contained.
Well so far I’ve collected 72 working cells. There have been many damaged or distorted cells which have gone into battery recycling bins.
Some of the unused cells awaiting a new “forever” home.
Early on I made two tiny packs to power my QCX radios. I have a small box that contains headphones, batteries, 2x QCX transceivers, ATU, SWR meter. This go-box is ready to grab, all I need is to pick up a paddle and antenna.
3S2P 1100mAh LiPo pack. Gives about 4-5hr QCX operation time. It uses 6 x 13400 cells which are 550mAh each.
I found some whoppers, 20400 1500mAh cells and made a 3S1P 1500mAh pack which would power a QCX for maybe 6-7hr. (AA cell for scale) The red item is a 3S LiPo/LiIon BMS. The JST connector on the packs is used for charge/discharge. Connect it to the JST on the BMS and 12V is on the coax power plug with undervoltage, overvoltage and short circuit protection.
But what to do with all the other cells? Well I could just drop them into a recycling bin but there’s no point dismantling the vapes if I want to do that. I did make an power pack for Mrs. FMF Roberts Revival radio. She has a summer house in the garden without mains power. I wasn’t buying disposable batteries so she now has a 2S2P 1100mAh pack in her radio. It’s been used several hours a week since May and the cell don’t need charging yet. So that’s one use.
I can be a bit pessimistic and I’m always worried I’ll do some big walk and then run out of battery power because I forgot to charge the battery after the previous walk. I have had the battery pack fail on a few activations. If it was just on my training hill Scald Law (35min drive 45min walk) then it’s not the end of the world but it is on big walks. Agains It’s not an issue should it happen when I have the 705 out as it has an internal battery. I have one for my KX2 but I can’t be bothered dismantling the radio to charge it so I don’t use it and my Sporran is welded shut so no internally charging option.
So for a long time (both in 817 days) and now with the KX2, I carry a second battery. Something with enough “oomph” to let me complete an activation. Though being LiPo cells, the voltage drops off more than LiFePo and so I only get 8W on 12/10m but who is going to notice. It’s just heavier and more than needed as a backup.
With a big walk coming up I wanted to minimise a lot of the excess weight. So having plenty of small ex-vape cells I came up with a super lightweight emergency power pack.
The first version is a 3S2P 1000mAh pack using 13350 LiPo cells. The cells are wrapped in Kapton tape for insulation (it’s thin and preferred for this purpose over PVC tape). There’s a balance connector for charging and a captive 2.1x5.5 coax power connectot. The whole item is wrapped in heat shrink.
That is probably good enough for upto 90mins on the KX2 at 5W output. More than enough for 4 QSOs. The only problem is I just don’t like these kind of cells not being in some kind of container. I don’t want them to get punctured or crushed. So whilst this works and does what it says on the tin, the lack of a tin or case makes me want to box it up.
That’s when I remembered Rick M5RJC’s post about his ex-vape packs for his 817 and his 3d-printed box.
I contacted Rick and asked if he would print something for 6x 13350 cells and posted it up. Tell me how much and I’d send him the money. And so it came to pass that 2 perfect 13350 cases arrived in the post. With snug lids and a wiring channel. Absolutely perfect.
I’ve built one up and soldered the cells together. I used some strips of copper foil about 2mm x 25mm x 0.1mm as there is not that much room for wire and that will have no problem with the 2A or so current flow. There’s a 4pin JST XH connector for charging and a 2.1x5.5mm power connector. Whilst the PLA material used is not as tough as Kevlar or carbon fibre, it’s going to offer just that bit more protection that heat shrink.
Here’s the finished item. It weighs about 1/2 the weight of the 18650 pack, about a 100g saving. it’s 115mm x 38mm x 16mm approx. so small enough to fit anywhere in my bag.
Now 100g is hardly anything. But a few more 100g savings here and there and that’s a lot more chocolate I can carry. So well worthwhile!
Many thanks to Rick for printing this for me. Now if only the rain would stop I could go out and test it in the field.
Likely I would’ve ignored it if it weren’t for your previous post.
Then everything becomes prescription based.
