qrz.is/content/post/battery-pack-building.md

---
title: "Battery Pack Building"
type: post
author: micha
date: 2022-08-27T16:00:00+02:00
url: /battery-pack-building/
tags:
 - DIY
 - battery
---

I have inherited the following collection of battery packs, which were already at least 5 years old at this time:

![image](/img/battery_packs.jpg)

Two battery packs should now be built from them: One as power supply for my Yaesu FT-817 during portable operation and another bigger one from the remaining cells. For this I took all packs apart, charged each cell and then measured their capacity: 

![image](/img/capacity_testing.jpg)

I also needed do order a spot welder kit for this. After I received the spot welder kit, I assembled it and built the smaller battery pack (4s2p) of the two with 14,8V and a capacity of 6200mAh. Worked fine but I had to use a 100Ah battery as power source to make it actually weld.

The spot welder:

![image](/img/spot_welder_1.jpg)

![image](/img/spot_welder_2.jpg)

The battery:

![image](/img/4s2p_1.jpg)

![image](/img/4s2p_2.jpg)

Then I've built the bigger battery pack in a 4s6p configuration with 14,8V and a cpacity of around 12,5Ah:

![image](/img/4s6p_1.jpg)

![image](/img/4s6p_2.jpg)