Review on Makita DC18RD Lithium Ion Optimum Charger by Matthew Baltimore

This charger has a new function. When the battery reaches 80%, both indicators remain lit. In related news, Makita has launched 4.0Ah and 5.0Ah battery packs in addition to 1.5Ah and 3.0Ah battery packs. some real info on maximum battery life and failure avoidance. This is an extremely complex topic, so I'll try to keep it to a minimum. First, a few general rules that apply to all common lithium batteries, and then I'll talk specifically about Makita 18V batteries. The most important thing to remember about any lithium battery is never to store it in a discharged state. Charge it as soon as it "discharges" and you will avoid many problems. The lithium battery does not need to be fully charged every time. In fact, if you don't fully charge it, you'll get more cycles. The battery performs best when it is between 20 and 80 percent full. When a battery is less than 80 percent discharged, it can draw more charging input voltage, allowing the charger to do what delivers more. When the battery is 80% full, the charger switches to a lower voltage, which means that half of the charging time is in the last 20% of the power. To prolong battery life, you must remove it from the charger before it is fully charged. With this new Makita charger, both lights will illuminate when the battery is 80 percent charged. When you see both lights are solid, remove it from the charger. This is an important new feature of this charger. Using it will extend the life of your batteries. Putting a lithium battery in a charger with any state of charge will not harm it. The battery can remain in the charger for a long time without damage, but there is a risk of fire. Take it out of the charger and disconnect it. There were many fires and lawsuits in 2008 and since then manufacturers have improved the safety of lithium batteries, but there is no battery type that can be left 100% unattended on a charger. The error is called VWF - Vent With Flame. Low temperatures do not harm the lithium battery. Cold gadgets don't last as long, but there's no permanent damage. However, it's not a bad idea to bring your batteries indoors when the temperature hits zero degrees. Lithium batteries can be stored in the refrigerator because the cold reduces the self-discharge rate, but this should only be used for long-term (more than half a year) storage. Place them fully charged in a ziplock bag or other sealed container. Never put them in the freezer. Extremely high temperatures will definitely shorten the life of the lithium battery. Temperatures above 140F or 60C should be avoided at all costs. There are several ways to kill a lithium battery.1. Charge it too fast with too high voltage. This should never happen with this charger.2. Charge it up. Again, this should never happen with this charger.3. OVERCHARGE is usually how you kill a battery. More on that soon. Some additional reading. Makita was the first company to introduce full lithium power tool batteries. They should be congratulated for that. But now, to maintain backwards compatibility, we need to deal with the deprecated cell balancing scheme. Inside each Makita 3.0 amp/hour 18V battery case are ten smaller cells using lithium-manganese chemistry. The cells are 18mm wide and 65mm long and are commonly known as 18650 size batteries. These are a lot more common than you might think, chances are you have the same 18650 processors in your laptop. They are becoming commonplace in high power flashlights. Tesla is building them into those fancy cars that are driving stock prices to the Himalayas, and Tesla's "giga-factory" being built in Texas will be producing 18650s. The cells in Makita batteries were manufactured by Sanyo until Panasonic bought Sanyo. Makita now uses Panasonic branded batteries. Some older Makita batteries may contain cells manufactured by Sony. Let's return to the problem of OVERDISCHARGING. Inside the Makita battery are ten 18650s and a small circuit board called PCB, Protection Circuit Board. Now I have a long quote from a guy who works under the nickname ToolMon. "Lithium batteries can burn or explode if mishandled. For security reasons, they must be monitored. monitors charging voltage, current, battery temperature, number of charges and remembers everything. Good idea right? But there is a design flaw. If you leave it for a while, the control board will deeply discharge the first cell to zero while the rest stay charged. the board remembers that. If you then try to charge the same battery more than 3 times with what appears to be a deeply discharged cell, conservative software on the control board will lock the battery permanently! The control board tells the Makita charger that the battery is not safe to charge and prevents charging in the Makita charger. Once the battery has been "shorted" it cannot be reset. "Get it? The control board is constantly drawing a small amount of current from just the first cell out of ten. If that first battery voltage falls below 2.5V, the charger will read this as a shorted cell and will not charge the battery. If you then try to charge it a total of 3 times the control board will permanently destroy the battery even if only one cell out of ten is dead.Fortunately there are ways to overcome a walled battery.You can buy a different brand of charger that the control board doesn't read which can lead to other problems.or use the dangerous way which I won't discuss here.But the real solution is NOT TO LET THE BATTERY DRAIN AT ALL.Recharge it immediately after use and you never will stand a chance of ruining the battery Also charge it if it's been sitting for months, don't let it sit forever Vision of the STARS: Another problem with old Makita lithium batteries is the lack of cell balance. Some items in the package can be fully charged, some not. I don't have a date when Makita introduced "STAR LOGO", I have instruments with a star that predate anything I've seen in Makita literature that mentions a star. If your battery and/or tool is marked with an asterisk or a small yellow tab on this charger, your battery is cell balanced. Some tool/battery combinations with and without an asterisk are not possible. I've found the yellow tab to be a better indicator of tool and battery compatibility than the asterisk. If both have a tab, then everything is fine. Another way to kill a battery: Almost all Makita tools communicate with the battery board, but some don't. I have about 20 tools and most of them will keep full power when the battery dies until they suddenly stop. But my little fan isn't like that, the speed of the motor gets slower and slower until I let go of the trigger. Haven't tried it but I bet the vacuum is the same. I know someone with an early radio and it keeps playing until the sound is really fuzzy and low but my new radio will be a little fuzzy for 10 minutes and then suddenly shut off. He says he bricked the battery in his radio when he left it on overnight, mine didn't. DO NOT OVER-DISCHARGE YOUR BATTERY! For security reasons, Makita leaves a small charge. The cells can be charged without any problems up to 4.5 volts, but the charger stops at 4.2 volts. (At least on older (green) chargers.) Not only is this much safer, but it also extends battery life. I don't know if this new black charger stops at 4.2v or if the 80% charge indicator (both lights are on solid) means it just hit 4.2v and keeps going up to 4.5v. I will update this review when I find out. I could delve into the chemistry of why a battery is permanently dead when dead, or the low/high voltage of each cell, but I think that's good enough for Amazon. Read here if you want to get past your head. http://www.candlepowerforums.com/vb/showthread.php?280754-makita-18v-lxt-batteries/page