When one 2ah M18 battery I owned began randomly flashing one bar and gave the flashing error on the charger, I began searching for a new one only to realize the cost was over $100! I decided to tear the battery down and find what was wrong. All of my battery's cells were in good condition, but the circuit board that monitors the batteries had kicked the bucket. I was about to toss this perfectly fine battery in the recycle bin as many people do before realizing the circuit board was replaceable. After replacing it, it responded like nothing had happened and I had just saved myself $100. I then decided to get some batteries from friends and coworkers to fix theirs, and here I am now.
Roughly 90% of batteries that are discarded are not properly recycled, and millions of power tool batteries end up in landfills every year. While this recycling issue primarily stems from a lack of easy and accessible recycling locations, the fact that so many are thrown away every year is concerning. Especially when these batteries are designed intentionally to hinder long term performance. It is safe to say that at least 50% of the batteries tossed each year had some small issue that could have been easily fixed, and for cheap.
With most major power tool battery brands, there exists a common issue: Balancing.
When cells in a series pack are imbalanced—such as one sitting at 3.9V and another at 3.2V—the battery management system (BMS) typically stops operation as soon as any single cell hits the low voltage limit of 2.5v-3v, or full charge value of 4.2v. During charging, the highest cell hits 4.2v first, cutting off the charger early and leaving the other cells (the pack) only partially full, which is why it won't show all indicator bars. During use, that lower cell drops to the minimum voltage cutoff long before the healthy cells, forcing the tool to shut down early due to "low battery" and resulting in short runtime. On a new pack, all cells are equal voltage, but as time goes on with usage and charging, this voltage drift naturally occurs, and is expected.
Strange part is, major brands do not balance their cells. Some of these batteries even feature cell balancing in their software to ensure cells can maintain the same voltage and resolve this issue. However, this is actually turned off in the software, thus leading to an inevitable cell imbalance and an early death date on your battery.
When you send me a pack exhibiting signs of cell imbalance, I will disassemble it and verify the issue. Upon noticing cell imbalance, I will then connect it up to my balancer and begin slowly bleeding cell voltages into each other until they all read the same. This is a cost effective way to solve the issue and give the pack many more years of life. However, this does take a considerable amount of time to perform on larger batteries.
Once balancing is complete on any pack, it moves on to the load tester. For your safety, batteries may be held for up to 2 weeks in the load testing phase to ensure no parasitic drain exists and that cells are not drifting from one another on their own.
On the load tester, I am able to simulate constant, heavy use on the whole battery pack to ensure it is not generating dangerous amounts of heat or voltage sag. This also allows me to tell how healthy the cells currently are and if they have become degraded.
One of the rarer failures in a battery pack is the battery management system (BMS) board. OEM boards do not exist, thus when replacing boards they need to come from donor packs or through third party copies that I trust. These tend to be the cheapest repairs on M18 batteries. Once replaced, it is load tested for safety.
If I open your pack and see that cells have died, it does not always mean the whole pack is unrecoverable. I can sometimes remove the old cells and install genuine brand replacements that exactly match the existing cells. In some cases it can even result in increased capacity in the pack!
Inspections are free, nothing is charged until you give me the word.
All repairs include cell balancing and load testing.
If a pack needs cells or the BMS replaced, I will get a price together and contact you before doing any of the work.
Voltage balancing & recovery prices M12* / M18 (or other brand equivalent):
CP 1.5, 2.0, 3.0 - $25
XC 4.0, 5.0 - $40
HO 6.0 & XC 8.0 - $50
HD, HO, Forge,** 9.0, 12.0 - $65
Discounts (can be combined):
$5 cash discount
$5 bulk discount on 3+ batteries
I only get paid if your battery leaves my bench working safely and taking a charge. If I open your battery and find it cannot be repaired or you do not like the quoted repair, you can choose whether I give the pack back to you for free or safely disassemble it for recycling. If a pack ends up showing signs that it is failing again within 90 days, I will service it once again for free.
Email: [email protected]
Text: 940-443-0457
*M12 batteries are primarily only balanced/recovered due to the compactness of the packs and cell placement. Depending on the cell position on higher amp-hour models, replacement cell packs may be possible.
**Forge packs are only balanced/recovered, no replaced cells due to complexity and risk. Larger HO packs vary depending on the affected cell.
*NOT AFFILIATED WITH MILWAUKEE OR ANY OTHER BRAND*