Bests & Worsts Reviews from Amazon

I love these batteries and the tools they power. They deliver more energy than my other brand 18 volt tools. The Makita smart charger charges them in 20 minutes. Wow, great battery! I should be happy, right? Partly I am, but partly I'm not. I am concerned about the huge number of premature failures people are reporting here and in the single BL1830 battery reviews. There's a problem and Makita is ignoring it. I did a lot of research on the net about this. My conclusion: this battery has design flaw that shuts down these batteries prematurely. It won't happen to everyone, but if the battery sits discharged for a long time, it's very likely to happen. Background: Lithium batteries can burn or explode if abused. They need monitoring, for safety reasons. So like everyone, Makita put in a smart control board in the battery pack. The control board monitors charging voltage, current, battery temperature, number of charges, and remembers all that. Sounds good, right? But.. there is a design bug. The battery control board draws power only from the first cell of the 5 cells in the battery. If you leave it sitting for a while, the control board will discharge that first cell to zero, while the others remain charged. To the control board or possibly the charger, that looks like a shorted cell, which could overheat, and the control board remembers it. If you try to charge it 3 times with an apparently deep discharged cell, sudden death! The control board tells the charger that the battery is unsafe to charge, and prevents charging in the Makita charger -- permanently. The key evidence is the apparent dead cell is usually that first cell, the one that powers the control board. Very likely the battery is still usable. It can probably be recharged on third party chargers that ignore the control board -- but never again on a Makita charger. If you have a dead battery, you could try to charge it on an aftermarket charger. They cost about $50, a lot less than a new battery. If you read the reviews for the single BL1830 battery, you will see that a lot of customers, about 1/3, are angry about these premature failures. Makita has extended the warranty if the battery fails before 150 charges, admitting they know about the problem. It's not enough. We should not have to deal with premature failures caused by a known design defect. Who has time on the job, and who has money to throw away? I can think of many ways to fix this. For example, Makita could reprogram the battery control board or charger so it did not lock up a good battery, or the control board could draw power from all 5 cells so this is less likely to happen to a single cell, or use a separate coin cell for the control board, or ... well, as you can see there are many possible ways to address this. My point is that Makita's engineers need to pick a solution and fix this problem. As I said, I really do love these batteries and tools. But this serious problem has been identified, and it needs to be fixed. In my opinion, Makita should recall these batteries and fix this problem, and release a better battery design for new sales. If not, Makita's reputation will continue to suffer, and there could be a class action lawsuit too. Makita is infuriating customers and destroying its reputation.