How to Impose Your Will on a Makita Battery

       The Makita DC18RA is Perfectly Capable and Willing to Red-Light a seemingly healthy battery to death, without explanation or apology. 

                                    My name is Dennis Pulley and

    here's how I hacked it;

                               

         It happens to someone everyday, they place the battery in its cradle for a routine charge and instead of the familiar green glow and accompanying Muzak Electronica, you get the dreaded Red Screech of tough titties, the Crimson Led of Doom,  the dry raping of a no-way-Jose prorated refund. Some of us take it better than others but, we all hurt in our own way. Maybe you get mad, after all, that was a $100 battery and less than 6 months old, maybe even called Home Depot and vented at some 20 year-old girl that happened to answer the phone, Shit No, I don't have the damn receipt, but it wouldn't even matter, because at the end of the day, you will still be a battery shorter than you were yesterday and nobody will care, not Makita, not Home Depot, not even Congress. Blatantly scammed in broad daylight. Right here in America!  Turns out, the DC18RA is actually programmed to run these safety checks before it can begin charging and if it happens to read malfunction, the battery is swiftly and irreversibly, Red-lighted to death. Marked forever.  No second opinion. No bargaining. No remedy. Too bad, soooo sad.

     
      The US seemed to take it pretty hard or maybe it was just me, the internet was loaded with theory but without results. Life was rough during this period, a man with one battery is ...half a man. Your charger is always right in the front of your mind. When you worked, it sat idle,  and when it worked, you sat off the clock. But, there were guys worse off than I, guys that only started with a single battery, they spent day after day, week after week, spinning their drills around manually, in a sad, 2-handed shuffle that crippled the hands and deformed the fingers.     but anyway, within 5 or 6 months,  life was nearly back to normal, but I had amassed a decent collection of these batteries, as I couldn't throw them out nor let anyone else, I knew they were still good, after all, a battery doesn't just go out in that fashion, it was simply having its charge withheld and I knew there was probably a way around it. With trial and error as my scientific method, I began dismantling the charger, I thought I could remove whatever safety systems it had and simplify its task to one of simply transforming the current and spitting it out. After a couple of hours working on the charger (and meeting my first dangerous capacitor), I had come to the conclusion that the safety system was integrated into another one or more of the components and I simply didn't have the skills to recognize the mechanics at the circuit board level, let alone, remove it. I moved on to the battery itself.

      Eureka! It's all in the wire sequence. In theory, the charger is capable of charging 10 of these batteries simultaneously, as long as the first battery in line reads correctly. The trick is in chaining them together correctly. These batteries actually have 3 leads and possibly a separation of the cells as they have a single negative terminal and 2 positive terminals of a similar but separate voltage. A neutral of sorts? Both positively charged terminals must be wired together for the charge to spill over like an icetray into the next cell in line.
 

   I stripped down 2 lengths of wire (probably speaker wire) and crammed 1 end into the negative contact on a battery that would still charge on the DC18AR normally, I then stripped 5 inches or so of another wire and ran it from one positive contact to the other on the working battery. I then attached that battery and its leads, to the charger, careful not to dislodge the contacts. I separated the loose ends from each other and plugged in the charger. Checking.....checking......checking......BEEEP! Green light! Charges just fine.    Next, I checked the voltage of my 3 empty leads. About 21 volts total and consistent, if I remember correctly. The only thing left to do was wire the 3 terminals on the 'bad' battery and hope a fault or short would not register. It didn't. The charging lights steady signaled normal operation and within 1 hour 10 minutes or so, I fully charged two 4ah Li-Ion Makita batteries, one of these had sat dead for 6 months prior to this Resurrection. The rate of charge scales perfectly, one 4ah battery used to take 30 minutes or so.

 
     Months later and crisis averted, I typically charge these batteries in chains of 4 with no problems, in about 2 1/2 hours. No excess heat. No explosions. And instead of losing $100 on these Makita batteries, I profited by unloading the problem batteries from anyone I could and by the nearly 50,000 hits this video has garnered on YouTube, earning me damn near $8. WooHoo! Hacking the job. Thanks for reading.

This is the charger that actually plays a tune.