I’ve been sharing each of my LiFePO4 DIY battery builds on Twitter, and inevitably people want to know what parts they need. They’re too many to list in a tweet, so I thought I’d keep a running page here to refer people to.
These things have been acquired over many months, and are not all inclusive. The reason I keep making them is to try out new things.
Typical 6.5Ah to 7Ah 32700 build:
- LiitoKala 32700 LiFePO4 cells: ~$3.50/ea, ~$14.00 per 12v 4S1P battery.
- 100A 4S LiFePO4 BMS: $7.10 per batt
- 32650 battery holders: $1 for 4 cells
- Wiring (12ga, 16ga, 22ga in bulk, multiple batts): ~$50, ¢ /ea batt
- Powerpole connectors (multiple): $99, or $1/ea batt
- Zip ties: ¢
- Mini latching switches (bulk): $11/40pcs, 28¢ /ea batt
- Mini 0.28” voltmeters: $2/ea
- Neoprene padding: $1.40/ea
- Kapton tape (roll): $11/roll, ¢ /ea
- Blue PVC shrink wrap 150mm: $14/roll, $1/ea batt
- Nickel strips (100 pcs): $19, 60¢/ea batt
- K2 26650 LiFePO4 cells (from BatteryHookup.com but out of stock at time of this writing).
- 8A 4S LiFePO4 battery protection board: $2.75 ea (Note: This tiny board does not balance, it just protects against over/under voltage, as well as short protection. Make sure your batteries are similar in quality and capacity, otherwise you will have degraded performance based on the weakest cell.)
- 115mm wide Blue PVC shrink wrap: $6.00 per 1m, ¢ /ea batt. (That link is good for different sizes of wrap, just measure the width & height of your battery and double it, then add 15mm for room to shrink).
All in all, about $30-$35 per build (and less for the 3Ah build due to less components). Also this stuff isn’t made without various tools:
- Car battery arduino spot welder
- Powerpole crimper
- Soldering station
- bunch of other tools and supplies for DIY electronics
You’ll of course need a battery charger specific to LiFePO4 chemistry (preferably 14.6v to trigger balancing, but 14.4v & 14.2v chargers are fine for general purpose). Do NOT use Li-on or lead acid battery chargers! I like Bioenno chargers for daily use, and when testing I use a iMax B6, though the B6 only goes to 14.4v for LiFePO4*.
I haven’t really made a how-to video since the process takes me forever and often there’s a lot of swearing. There are tons of other videos on the topic of LiFePO4 DIY battery construction.
I’m also not selling these, they are just tinkering and experimentation on my part with a goal to power my ham radios. Here’s an early video I did testing some cells. The expanded description in the video has a list of parts as well.
*The eBay and Amazon links above are part of an affiliate links program where I get a small commission at no change in price to you.