DIY Battery Holders¶
3D Printed Battery Holders¶
For many years I have been purchasing battery holders for cylindrical cells. AA Ni-Cd, then Ni–MH were the cells I would use most often. 8 AA cell holders were the making size I used most often for RC transmitters, but 2 and 4 cell AAA and AA were often used for robot projects requiring 5-6 VDC for servos etc.
Why Battery Holders¶
Battery holders allow for: 1. Use of loose individual cells 2. Cells removal for charging on advanced chargers 3. Reliable power delivery when designed properly with good contacts and cell retention geometry 4. Quick removal of under-performing cells.
Ni-MH Sanyo Eneloop Batteries¶
Ni-MH Sanyo Eneloop Batteries are excellent and provide more current than other types of batteries chemistry. I often noticed other folks using alkaline batteries for servo driven robot projects claiming that special regulators and other circuits need to be added to power multiple servos. This is not my experience when using Ni-MH Sanyo batteries, there is plenty of current available to drive multiple servos and a MCU at 1.2 x4 = 4.8 volts. However I often wished that I could use 1.2 x 5= 6 VDC packs. That would allow some headroom for voltage sag under heavy loads.
Battery holders¶
I have had many 8xAA battery holders over the years almost all of them have performed very well and reliably for powering critical radio control transmitters where failure is not an option. These holders use a riveted design with spring wire and disk and spring type contacts.
I often wondered if custom battery holders could be made that would be as reliable as purchased battery holders. Then I could buy individual cells and make my own holders and packs with balance leads and other advanced charging features that are not available in purchased holders
18650 Li-Ion Batteries¶
Around 2019 I started using higher capacity 18650 cells for various projects, including powering systems launched in high altitude balloons. The need for custom battery holders re-emerged.
I am also looking at using high current capability 18650 cells for long duration RC aircraft flights.
21700¶
In 2020 I started using Radio Controls that used very high capacity but expensive 2 cell 21700 packs. I wanted to make my own holders for 21700.
Battery contacts¶
In my search for making my own reliable battery holders I came across Keystone Electronics Corp. and their Button, Leaf Spring and Coil Spring Battery Contacts For PCB and Molded Case Applications These contact may be a starting point for making my own lower cost custom battery holder packs.
I will be revisiting here once I design and make some battery holders using these components,.