makita 18v lxt lithium-ion battery repair - lithium ion rechargeable battery

I have been a big fan of Makita 18 v LXT cordless tools for several years.
In most cases, I rarely use the wired tools they have replaced, though, the battery seems to be a major week.
Of the eight batteries I have purchased over the years, four have failed outside of the warranty period, and in addition, after the warranty is over or just over, two have failed and are replaced free of charge by Makita.
There seem to be two main causes of failure the first one is overheated and the second one is the first two batteries fail because they are used to power the battery management chip and discharge slowly over a longer Idol cycle.
This causes the battery to be unbalanced.
Once you get three red/green flashes on your charger, your battery Control Board will lock the battery out of charge.
I will focus as often as I can on replacing the battery control board, which is everything I need to do to start up and run, although these can be easily replaced if you do need new batteries.
Makita seems to use Sony Konion LiMn batteries, which are available online at a price of between 10 pounds and 30 per battery, or you can pick up expired batteries on ebay frequently,
If you do need to replace the battery, then welding to the battery is the best way, just like welding you have the risk of overheating.
The battery tag spot welder does appear on ebay from time to time, or something that electronics enthusiasts can make on their own.
Before we start dismantling, keep in mind that even if your batteries are no longer working, they are likely to contain a lot of energy.
Be careful how you handle them, and the most important thing is to make sure you don't miss them.
So the first step is to uncover the cover.
This is supported by four T10 tamper-proof screws, and on newer models there may be a white tamper-proof screw covering one of them.
The easiest way I found was to drive it with a small wooden screw and pull it out with pliers.
Once you turn on the battery, be careful to keep the clip spring from flying away and not short-circuiting the control board, and you should be able to see if there are any obvious major issues.
The first time I turned on one of the batteries I was surprised how much dust was in the battery and I quickly learned to keep my charger away from dust and never charge them on the floor!
If you see any obviously damaged cells when you open, you will have to replace them, which is beyond the scope of this article.
I have four failed batteries that check the voltage of the battery and the battery pair separately.
I found the following points: by comparison, a known good battery seems to be able to measure about 20 v when fresh charging.
So I decided that my best option would be to change an extra working battery because it's all very close to the voltage, which shows it charges fairly evenly.
Until recently, replacing the board was not available, so your battery will be brick once you see the red/green flash three times.
Recently, however, they have been able to get a round battery of £ 10, which is definitely much cheaper than replacing the battery.
It will be more challenging to repair other batteries.
Whist can weld the heat required to weld the battery together, which has the potential to damage the battery.
After investigating the purchase of a battery label spot welder, I felt it was out of my budget, but I might try to make a capacitor discharge welder.
The control board comes with the OK instructions on how to install it, but they don't explain everything, probably because it can be used with all the models of the 18 v LXT battery produced by Makita.
As long as you have a little common sense, you should be fine.
So you may need to cut a lot of plastic in addition to welding, which assumes that you are as lucky as I am and don't need to replace any batteries.
If you spot welding the battery is the best way to do it, just as there is a risk of overheating when you weld.
As I used to take the battery pack out of the box, the first thing is to remove the existing pcb as per the instructions and cut off the plastic pcb holder etc.
I chose to cut the nickel contacts instead of going to the weld.
While I had to get my bigger soldering iron out, it was simple to weld the pcb and wires to the contacts.
The hardest part so far is to get the lid back and it took a little time to make the plastic fit.
Next is the moment of truth, I put the battery on the charger and charge it.
I then fully discharge the battery and charge the battery again, which also works.
The battery is still perfect for eight months.