zapp_brannigan
I am not a Futurama fan .
You can build a battery pack from recycled cells from decommissioned rechargeable equipment or even the modern-day hybrid vehicles for instance Nissan E power /Leaf or Outlander (forget about Toyota they use a different battery chemistry which is very hard to work with ).
I have been using such a battery since May 2023 to power the house coupled with a hybrid Inverter. In December 2024 I built a second pack which now allowed me to power most of the household loads from the off-grid setup. The only items on KPLC are the instant shower and oven. The two DIY packs are approximately 10.3 kWh capacity.
The use cases for the battery packs are endless. For those with solar floodlights that don't last from dusk to dawn, these are fantastic cells. I have even used the 12v 15 Ah to jumpstart my neighbor's vehicle a couple of times. Even though the cells are used there is so much life left.
The first pack I built in 2023 was made of two parts each 24v 96Ah . The whole pack is made of 512 cells each rated at 3Ah . The whole pack is in a 8s64p configuration.
Below is a table listing the main components that you require
Kapton Tape
BMS - This is the controller that manages the charge, discharge, and balancing. I highly recommend the JK BMS brand .
4mm sq /6mm for use as bus bar (size depends on the current being drawn)
A small 12v 15Ah pack to power a portable LED flood light . This pack here can just start a vehicle (tried and tested )
A replacement 9Ah pack in use on a cordless drill .
Tested and graded 26650 3Ah lifepo4 cells from Enviroserve
This is how the cells are tested, graded, and labeled at Environserve to ensure the cells are in a healthy state and safe.
2p 26650 cell brackets
2P 26650 Nickel strip 0.15
2P 26650 cell brackets
4 packs - 3.2 v 196Ah per pack. This pack in series gives you 12v 196Ah .
Once you have the materials, assemble the cell brackets accordingly. Cut the nickel strip to an appropriate size that matches your assembled cell brackets.
You can find videos on the dos and don'ts of spot welding on YouTube. In my builds, I ensure the battery welding surfaces are free from dirt or any foreign particles. Some cells may require some sanding once done I use the isopropyl alcohol to clean the positive and negative surfaces of the battery where the nickel strip will be placed. It is also good practice to clean the nickel with the alcohol.
The next step is spot welding followed by soldering of bus bars. Follow the BMS wiring guide from the manufacturer to attach the balancing leads. Once done use the Kapton tape to insulate the surfaces that are at risk of short circuit.
Always be careful when handling these cells the stored energy can be dangerous in case of a short circuit.
I have been using such a battery since May 2023 to power the house coupled with a hybrid Inverter. In December 2024 I built a second pack which now allowed me to power most of the household loads from the off-grid setup. The only items on KPLC are the instant shower and oven. The two DIY packs are approximately 10.3 kWh capacity.
The use cases for the battery packs are endless. For those with solar floodlights that don't last from dusk to dawn, these are fantastic cells. I have even used the 12v 15 Ah to jumpstart my neighbor's vehicle a couple of times. Even though the cells are used there is so much life left.
The first pack I built in 2023 was made of two parts each 24v 96Ah . The whole pack is made of 512 cells each rated at 3Ah . The whole pack is in a 8s64p configuration.
Below is a table listing the main components that you require
| Item | Source | Link |
| 26650 Cells | Local - tested and graded | Enviroserve Kenya |
| 2p Cell Brackets | China | https://bangteng.en.alibaba.com/?tracelog=from_orderlist_company |
| 2P 26650 Nickel Strip | China | https://jsdzx.en.alibaba.com/?tracelog=from_orderlist_company |
| BMS | China | https://jkbms.en.alibaba.com/?tracelog=from_orderlist_company |
| Kapton Tape | China | https://jsdzx.en.alibaba.com/?tracelog=from_orderlist_company |
| 16mm sq cable | Local | |
| Cable Lugs | Local |
| Tools /Misc | Source | Link |
| Spot Welder | China | https://www.seesiius.com/collection...ot-welder-80-gears-adjustable-with-lcd-screen |
| Soldering Gun | Local | |
| Solder | Local | |
| Isopropyl alcohol | Local | |
| Pliers | Local | |
| Heat Shrink Tube | Local ( | Nerokas /Ktechnics/Pixel Electric |
| Hydraulic Crimping Tool | Local | Tronic /Jiji Kenya |
Kapton Tape
BMS - This is the controller that manages the charge, discharge, and balancing. I highly recommend the JK BMS brand .
4mm sq /6mm for use as bus bar (size depends on the current being drawn)
A small 12v 15Ah pack to power a portable LED flood light . This pack here can just start a vehicle (tried and tested )
A replacement 9Ah pack in use on a cordless drill .
Tested and graded 26650 3Ah lifepo4 cells from Enviroserve
This is how the cells are tested, graded, and labeled at Environserve to ensure the cells are in a healthy state and safe.
2p 26650 cell brackets
2P 26650 Nickel strip 0.15
2P 26650 cell brackets
4 packs - 3.2 v 196Ah per pack. This pack in series gives you 12v 196Ah .
Once you have the materials, assemble the cell brackets accordingly. Cut the nickel strip to an appropriate size that matches your assembled cell brackets.
You can find videos on the dos and don'ts of spot welding on YouTube. In my builds, I ensure the battery welding surfaces are free from dirt or any foreign particles. Some cells may require some sanding once done I use the isopropyl alcohol to clean the positive and negative surfaces of the battery where the nickel strip will be placed. It is also good practice to clean the nickel with the alcohol.
The next step is spot welding followed by soldering of bus bars. Follow the BMS wiring guide from the manufacturer to attach the balancing leads. Once done use the Kapton tape to insulate the surfaces that are at risk of short circuit.
Always be careful when handling these cells the stored energy can be dangerous in case of a short circuit.
Attachments
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