Makita BL1830-2 18-Volt 3.0 AH Battery, 2-Pack

There is an intelligent circuit board inside the pack that needs to be powered, and it draws its power from the very cells it is monitoring.

The basic design flaw is that the circuit is wired to be powered by only one of the many cells in the pack. The board draws a constant although small current from that single cell. If the battery is not used for a few weeks then that cell will deep discharge causing a weak link in the bank of cells, the pack then fails in the charger.

Makita has programmed the circuitry so that if you try to charge the battery 3 times in this state, it will permanently disable it. Normal behavior is to think "why is it not charging, let me try again". If more than 1 year old, it is out of warranty.

Makita should step up, redesign the battery, and offer on their website to replace any batteries which have not been abused with the new design.

I would not buy any more Makita tools powered by this battery.

These batteries are a great value because they last a lot longer than other 18V batteries. I have crews using these tools for metal framing and such and the less time they spend getting down off of scaffolds looking for a charged battery, the more money I save. I personally used the 18V driver to install 18 sheets of Durock and I went thru over 300 fasteners on a single charge. I kept reaching for more fasteners wondering when the battery would go dead and it just kept on going. The 3 amp hour design is awesome. In this case, I say you get what you pay for...and maybe a little bit more.

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...Read more