Rebuilding a Ryobi 40V 5Ah Battery

Rebuilding a Ryobi 40V 5Ah Battery

In this post we will share our experience and thoughts from replacing the cells in a Ryobi 40V 5Ah battery and compare it with the option of buying a new one.

One of the most popular brand for low-cost power and garden tools comes with a quite pricey battery. If properly maintained the battery can last many years, without losing much of its capacity, but when it starts failing it needs to be replaced.

While buying a new one is an option, the price tag makes many think twice before they buy. At the time of this writing the low-end, low-capacity Ryobi 40v 4Ah is priced at $218 with a temporarily reduced price of $172 at a popular big-box store, while the high-capacity 6Ah costs $328.

The other option is to rebuilt the battery by replacing the cells with new ones, just like we did with this Ryobi 40V 5Ah. In our example we replaced all 20 cells (LGABHE21865 P263I196AB) with the equivalent BAK N18650-COP. The final cost of the whole rebuild was around $100, which was basically the cost of the cells.

The challenge of rebuilding the battery is the process of doing so. You need to have basic understanding of how the cells should be connected to each other, basic soldering and spot welding skills, knowledge of how to use a multi-meter to make sure the cells are properly connected to the BMS and a myriad of other concerns related to electronics and lithium batteries.

So, is rebuilding the battery worth it? The answer is, yes and no. Yes, because, you end up with an essentially new battery that costs a fraction of a new one and no, because, it is a quite laborious task and it requires basic but essential specific skills and tools to complete it.