How to make DIY Li-ion 18650 Battery Packs for your Ham Radio QRP rigs

[@randalltom9750]

Linas, I love your videos... I've bought an enclosed battery holder, with a BMS, with a 5.5mm 2.1mm But the battery of choice for me is the TalentCell 12v 3aH. This works great with my KX2. The KX2 will automatically draw from the source of highest voltage. The TalentCell mates perfectly with my QCX Mini(s), QDX, and QMX transceivers... I love my QCX Mini with the K6ARK CapKey mod! It's very compact and portable!

[@Linas_LY2H]

Thanks Randall! You've got a nice setup with this versatile power bank including the 5V port! 73! Linas LY2H

[@G7MJV]

Thanks for a great video, very interesting

[@bojanrimanic6010]

Dear om tnx for this video. Very usefull. Can you please explain how do you charge this battery packs? Tnx.

[@Linas_LY2H]

Hello Bojan, thanks for watching! I charge my packs with special charger designed for Li-Ion batteries, it's made by Tenergy company and is rated for charging 3S packs ( those made of 3 18650 cells in series). It could be a charger made by any company, it's just important they were dedicated for Li-Ion packs, not for any other type. Also, the charger must produce the correct voltage for your battery pack. So, if the pack is made of 3 18650 cells in series (3S pack) its max voltage will be 12.6 V ( 3X4.2V=12.6V. 4.2V is a max voltage of 1 fully charged cell). It means, the charger must also produce 12.6 V (NOT MORE, overcharging could be dangerous for lithium batteries). Normally, the voltage should be written on the charger's case. The charging current should be 2A for these cells for normal charging. The charger should provide Constant Current and Constant Voltage (CC/CV type of charging algorithm). This is very important because it guarantees that charging will stop as soon as the battery reach its maximum voltage (12.6 V). Normally, if there is written on the charger it's designed for Li-Ion batteries, it will automatically be of the right type. As always, if you Google for "charging 18650 li-ion battery" you'll find lots of interesting reading :). Hope, this helps! 73! Linas LY2H

[@bojanrimanic6010]

@@Linas_LY2H thank you for explanation. Just one more thing. Do you use the same cable on the battery pack for charging the batteries as well as for connecting to the KX2 or is there another cable for charging it. I don’t see additional charging cable in the video and this is confusing me :)

[@Linas_LY2H]

@@bojanrimanic6010 No, there is no other cable for charging only. The original KX2's battery which comes with the radio is also of the same 3S pack type and it only has 1 cable both for charging and using. It means, you can not use the battery and to charge it at the same time in this type of packs. As in KX2, you need to disconnect the battery from the radio and connect it to the charger for charging. I think, it's related with the type of the BMS used with the pack. Frankly, I have never seen any other type of BMS then this for small 3S or 4S battery packs. But on big batteries , like my new 48V e-bike battery, there are two ports installed, one for using , one for charging. But there are many other e-bikes batteries with just one port, and you have to disconnect it from the bike for charging. So, it's an interesting topic, thanks for raising the question!

[@bojanrimanic6010]

@@Linas_LY2H Tnx Linas, everything is clear :)