Cordless Drill Battery Articles

How To Fix Common Ryobi 18V Battery Problems

In my opinion Ryobi 18V cordless tools are some of the best available, although it does seem that the batteries can suffer from numerous problems. Replacement batteries are certainly not cheap, and most of us will want to avoid the need to buy a new battery if at all possible.

Let's take a look at the most common Ryobi 18V battery problems and how to fix them.

Ryobi 18V Charger Red And Green Lights Flashing

The most common cause for your Ryobi 18V Charger showing flashing red and green lights is that the battery has been over-discharged.

What this means is the battery has been discharged to such a low level that the charger has trouble detecting if the battery is healthy or not and decides to not risk charging it - showing the dreaded flashing red and green lights.

This is commonly known as the battery being in "sleep mode"

The problem here with Ryobi 18V chargers, is that they don't incorporate a "boost" feature that would allow a a battery that has entered sleep mode to be woken up again.

As with any DIY fix with cordless tool batteries - it does have some dangers involved. Battery university recommends not boosting batteries that have been in sleep mode for a week or longer.

So keep this in mind when carrying out the following recommendations.

There are two ways to try and wake up a sleeping battery.

1. Use a second healthy, fully charged battery of the same voltage and connect the terminals matching polarity (positive-positive, negative-negative) using wires and leave them connected for a few minutes. Then try charging the battery again - this may be enough to kick the battery back into life.
2. Use a DC power supply set at the same voltage as the battery and connect the positive output to the positive battery terminal and the negative output to the negative battery terminal. Once again, leave this connected for a few minutes then try charging the RB18L50 battery.
3. This method should only be used if you don't have a spare battery or power supply as per option 1.

Patience is required here - so read these instructions carefully and find somewhere comfortable to sit!

• Connect you charger to the power outlet
• Place the battery in the charger until the green indicator goes solid
• Just before the red/green lights start flashing, remove the battery from the charger
• Re-insert the battery into the charger again and repeat steps 2-3
• Do this until the green light flashes constantly (might take up to 30 minutes)

Why does this work? Well each time you insert the battery into the charger, it gives it a small amount of charge before detecting the battery as sleeping.

So repeating this process over and over results in the battery slowly being charged in very small increments each time.

Eventually, this results in enough charge for the battery charger to resume normal charging operation.

Battery Too Hot or Cold

So while we all love the Li-Ion technology of modern day batteries, it does have some problems that older styles of battery didnt have to worry about.

One of these being the narrower range of temperatures that they will operate, and charge in:

So, the first thing to check if you are having problems with your Ryobi batteries is if they are indeed too hot or too cold.

If it is exceptionally cold where you usually store/charge your batteries, bring them inside and let them warm up to room temperature and then try charging them again.

If it is a hot day, or you have been using your batteries already and they are quite hot, try throwing them in the fridge, or taking them to a cooler area for a short amount of time before trying to charge them again.

Corroded or Dirty Battery Terminals

If the metal contacts on the P108 battery or charger become dirty or corroded, then it can cause the Ryobi charger to incorrectly assume that the battery is faulty.

If your terminals are corroded, then the corrosion can be removed with a piece of sand paper.

Dirt on the terminals can be removed with a wire brush or an alcohol-soaked wipe.

Sometimes getting to the actual terminals can be difficult due to them being recessed, if this is the case you will need to try different tools or items to reach them for cleaning purposes.