Ryobi Lith -ion battery problem

[619DioFan]

Battery in question is an 18 volt 2ah lith-ion.
Problem - will not operate any of my ryobi tools.

Tested the battery with my dvom and it reads 18.2 volts at the terminals on the battery so that is a full charge yet when installed in any of the tools - nothing. have 5 other batteries and all tools work on the others. when placed in one of the charges ( have 3 ) it reads defective. tried " boosting " it with my automotive jump starter - did nothing. why would a battery that reads full charge not run the tools ?

 

[Mechanical Noise]

My guess is that you've got a bad internal connection inside the battery which will pass the very slight current the meter draws but can't pass enough current to run the tool.

 

[rantapawan]

My guess is that you've got a bad internal connection inside the battery which will pass the very slight current the meter draws but can't pass enough current to run the tool.

In bad internal connection case the multimeter shouldn't display 18.3v output.

Sent from my Redmi Note 7 Pro using Tapatalk

 

[Mechanical Noise]

In bad internal connection case the multimeter shouldn't display 18.3v output.

Sent from my Redmi Note 7 Pro using Tapatalk

Let's say the bad internal connection has a resistance of 1000 ohms. How much voltage would that drop with a 10 megohm input meter? It's insignificant. If you want to calculate it, feel free.

 

[xlowxyotax88x]

Just because you have voltage doesn't mean you have amperage

 

[Mallen]

That's one possibilty. You could try getting a big fat 25w 20 ohm resistor. Put some wires with alligator clips on it. Don't use wire that's too small. Lamp cord or something will be fine. Now clip the resistor to the probes on your meter. Then measure the battery voltage. The resistor could get fairly hot so you might not want your fingers on it. If there's a large internal resistance then most of the voltage drop will be there and you will see a much lower voltage across the 20 ohm resistor. If on the other hand you still see the full battery voltage, then the current path is ok.

If that's the case, you likely have one of those "smart" battery packs. The onboard controller thinks there's a problem and the tool communicates with it and refuses to run. Either that or it's failed completely and the tool refuses to run because it's no longer communicating at all. Check the other contacts. It could be that there's a mechanical problem with the communications line to the battery controller.

 

[webscrounger]

Just a thought. Can you cover the smart contact in the battery and try using it as a dumb battery.

 

[Mallen]

I never tried that. It might work with some tools.

 

[Mallen]

It might have issues though. For example, you could potentially discharge the battery past the cutoff point. Then you'd typically have to disassemble it to jump it back up. And if it goes so low it reverses, your battery could explode or catch fire.

The battery potentially exploding or catching fire isn't exactly a deal breaker jumping batteries of course. Like I noted in a previous post though, you should make certain that you have it in something non-flammable in a place that you won't worry about the toxic fumes.

 

[webscrounger]

Would that then not be true with the Ryobi non-smart batteries also? Especially when used in tools that accept smart batteries?

 

[Mallen]

Not necessarily. My thought is, if a manufacturer made a battery and set of tools that depended on the battery manager to tell the power too the battery was dead, they might not have the normal cutoff that most lithium ion cells have. I wasn't speaking of only Ryobi tools, but any lithium ion tools. Its obviously really a really stupid idea to try to save 15 cents by leaving out the protection circuit and rolling it into the battery manager microcontroller and depending on the tool and the charger to communicate with the battery and refuse to operate. There are probably a dozen ways that could go sideways. But it wouldn't surprise me to find something like that in some cheap import tool. I would hope a Ryobi tool would not work like that. They may not be the top of the line tools, but they are ok, and you expect something sold by a large brick and mortar chain not to be downright dangerous. But I would be careful and watch for it with ANY tool. Sometimes even big companies that are respected for the quality of their products do stupid things to make a few extra bucks.

In other words, while it probably IS made right, I wouldn't assume it, even on big name brands. Just proceed as if it were not until you can verify that it is.

 

[webscrounger]

OK. Just AFAIK Ryobi batteries are supposed to be backward/forward compatible with their tools but I am not an expert, just a consumer/user. I have both smart and dumb Ryobi tools and batteries and use them interchangeably. So far not issues in using or charging. Sorry OP. Didn't mean to distract.

 

[goldtang]

Battery in question is an 18 volt 2ah lith-ion.
Problem - will not operate any of my ryobi tools.

Tested the battery with my dvom and it reads 18.2 volts at the terminals on the battery so that is a full charge yet when installed in any of the tools - nothing. have 5 other batteries and all tools work on the others. when placed in one of the charges ( have 3 ) it reads defective. tried " boosting " it with my automotive jump starter - did nothing. why would a battery that reads full charge not run the tools ?

Was in the local hardware store a couple of months back
and while waiting person there was getting there battery replaced as there was apparently an issue with some some battery’s from Ryobi not sure which ones may be worth looking into

 

[PoorUB]

In bad internal connection case the multimeter shouldn't display 18.3v output.

Sent from my Redmi Note 7 Pro using Tapatalk

One would think so,but a modern VOM uses so little power test that very poor connection with no load will show voltage.
I like the idea of testing it with a load, even a couple 12 volt light bulbs in series would work. Use jumpers and see if the battery will light the bulbs. But perhaps because it is a smart battery it needs a proper signal from the tool to work.if nothing else I would be tempted to carefully cut it apart and check all the connections. My bet there is a broken connection that satisfies a volt meter but fails under load.

 

[619DioFan]

I had sort of forgot about this thread. as a follow up I did open the battery and inspect the insides , I didn't see any loose connections nor signs of burnt spots on the board. as a final test I connected leads from the battery to one of the tools with a dvom inbetween the two. just sitting the meter read 18 volts. as soon as I pulled the trigger on the tool the voltage read 0. this concluded my limited testing skills so I replaced said battery. I have multiple batteries as most of my tools are ryobi and haven't had any issues with any other batteries nor the tools themselves.

 

[Mallen]

I had sort of forgot about this thread. as a follow up I did open the battery and inspect the insides , I didn't see any loose connections nor signs of burnt spots on the board. as a final test I connected leads from the battery to one of the tools with a dvom inbetween the two. just sitting the meter read 18 volts. as soon as I pulled the trigger on the tool the voltage read 0. this concluded my limited testing skills so I replaced said battery. I have multiple batteries as most of my tools are ryobi and haven't had any issues with any other batteries nor the tools themselves.

That was essentially the same as checking with a resistor as I suggested. It could have been a bad connection either between the cells or even inside a cell.