toolboy's Corner: Ryobi 18v Batteries

Over time the 18v battery packs have increased in performance and decreased in weight. All of these packs are interchangeable, meaning that any of these packs can be used with any of the Ryobi 18v tools, including the old blue/yellow and the new neon green
Model Chemistry Appearance Weight (measured) mAh Rating % Power compared to P100 Features Comments
130224007, 130256001, 1322401, 1322705, 1323303, 1400672 Nickel Cadmium 1lb 15oz / 880g (measured) 1500mAh 88%    
P100 Nickel Cadmium 1lb 15oz / 880g (measured) 1700mAh

...or 1500mAh??
  • The "standard" battery pack to which the Lithium Ion packs are compared
  • P100 Manual (143KB)
P102 Lithium Ion 15.4oz / 430g (measured) 1300mAh
(But more like 1200mAh)
  • 45% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • 20% more performance than standard NiCad batteries
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • Battery label indicates 24Wh -- same as the "old" P103 batteries
  • Click Here for a information dedicated to the P102
  • P102/105 Manual (1,406KB)
P103 Lithium Ion 1lb 1oz / 480g (measured) 1300mAh

...or 1500mAh??

NOTE: Ryobi doesn't state this anywhere. Ryobi's only claim is 20% more power than the P100, and 1.7*1.2=2.04 hence one might assume a rating of 2.04Ah. But this is DEAD WRONG. The cells inside are Samsung INR18650-13Q, which are 1300mAh cells!

...or 88%?
  • 45% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • 20% more performance than standard NiCad batteries
  • Smaller than all other packs at 1-7/16" tall "battery" portion, as compared to 2 3/16" "battery" portion on all other packs
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • Measured weight is 45% less than P100, just as claimed. 1-(480/880) = 45.45%
  • Actual power is 1300mAh, which is 23.53% LESS than P100, not 40% more than P100 as claimed!
  • Update 29-Aug-2012!
    Looks like Ryobi has finally updated the P103! Today I tested one with date code CS1217 at well over 1300mAh. Looking at the label, I see that it's rated 28Wh -- all the P103s I've seen before now have been rated 24Wh. That's 16% more energy and means that Ryobi must be using 1500mAh cells in their latest batteries.
  • P103/104 Manual (884KB)
P104 Lithium Ion 1lb 11oz / 770g (measured) 2400mAh

...or 2600mAh??

...or 153%?
  • 2.4Ah Lithium Ion battery pack
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • Has 2X the run time of standard NiCad batteries
  • 20% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • On-board fuel gauge indicates battery power status
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • Measured weight is 12.5% less than P100, not as much as the 20% claimed. 1-(770/880) = 12.5%
  • Update 29-Apr-2010!
    I've tested hundreds of P104s and NEVER had I seen one test at or above 2400mAh. Until now. This week I received a batch of P104s with date codes between CS0938 and CS0950. With the CS0948 date code it seems that Ryobi has made a change for the better! All of the P104s I've tested with date codes CS0948, CS0949 and CS0950 have tested ABOVE 2400mAh, as high as 2619mAh! I haven't cracked one open to confirm, but suspect that they're now using the same Samsung 1300mAh cells as the P103, for a 2600mAH P104 pack. In addition to the newer date code, I've noticed that the newer packs indicate "45Wh" whereas the older packs indicate "46Wh" (and even older P104 packs have power rating at all).
  • Update 07-Sep-2012
    I just realized that the current crop of P104 batteries are marked 48Wh. So I'd say that even Ryobi agrees that the current P104 is 2600mAh.
  • P103/104 Manual (884KB)
P105 Lithium Ion 1lb 8.44oz / 693g (measured) 2400mAh 141%
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • Has 2X the run time of standard NiCad batteries
  • 20% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • Battery label says 45wh, same energy as P104
  • P102/105Manual (1,406KB)
P107 Lithium Ion 1lb 0.2oz / 460g (measured) 1500mAh 88%
  • 45% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • 35% more performance than standard NiCad batteries
  • On-board fuel gauge indicates battery power status
  • Extreme weather performance
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • P107/108 Manual (1,449KB)
P108 Lithium Ion 1lb 9.2oz / 720g (measured) 4000mAh 235%
  • Holds charge 4X longer and reduces the need to recharge during long periods of non-use
  • Has 4X the run time of standard NiCad batteries
  • 20% lighter weight than standard NiCad
  • Lighter weight reduces user fatigue
  • On-board fuel gauge indicates battery power status
  • Extreme weather performance
  • Must be charged with a Dual-Chemistry charger, not with older NiCad chargers (P110, P111, P120, P130)
  • This is the battery we've been waiting for! The BIG one! At 4 Amps, it's by far the most powerful One+ battery!
  • P107/108 Manual (1,449KB)
P190 Lithium Ion 15.6 oz / 445g (measured) 2000mAh 118%
  • 2.0Ah half-height battery. No fuel gauge.
P197 Lithium Ion 1lb 10.4 oz / 750g (measured) 4000mAh 235%
  • 4.0Ah full-height battery. With fuel gauge.
??? Lithium Ion ??? 3000mAh 176%
  • 3AH High Energy Battery is half-height, but still larger than previous half-height batteries
??? Lithium Ion ??? 6000mAh 353%
  • 6AH High Energy Battery is larger than previous batteries
P194 Lithium Ion ??? 9000mAh 529%
  • 9AH High Energy Battery is much larger than previous batteries
NOTE: Ryobi also sells batteries in kits labeled P101, P106, P109, P122, P170, P161, P181, P184, and P185. P101 = two P100 batteries, P106 = 2x P103, P109 = 2x P107, P122 = 2x P108, P170 = 2x P102, P161 = 2x P190, P181 = 4x P102, P184 = 2x P105, and P185 = 3x P105.

So what do some of the features in the above table actually mean?

mAh Rating

A battery pack's mAh rating is an indication of how much power the pack has. In general, the larger the number the longer the battery can be operated before a recharge is needed. Unfortunately, many factors influence how long a battery will last after a fresh charge, including battery age, number of times the pack has been recharged already, temperature, the tool used, and other factors.

Just to give some sort of not-too-unrealistic and tangible comparison, let's say we compare how long each battery pack might theoretically operate a P704 flashlight if in new condition and operating in optimal conditions. For the sake of argument, let's say a P704 flashlight bulb draws a steady 600mA of current (=0.6A) until the battery pack is depleted. In this case, I'd expect the P100 battery to operate the flashlight for 1700mAh/600mAh= 2.8 hours. The P102 and P103 would last 1300mAh/600mAh = 2.2 hours, the P107 would last 1500mAh/600mAh= 2.5 hours, the P104 and P105 would last 2400mAh/6000mAh= 4 hours, and the P108 would last 4000mAh/600mAh= 6.7 hours

Wh Rating

Some of Ryobi's battery packs have an energy ratng on the label, expressed in "Wh" or Watt-hours. In its simplest terms, Watt-hours is an expression of Voltage x Current. This is a more precise measure of the amount of energy in a battery packs than milliamp-hours (mAh), as it takes into account both voltage level and current draw during the discharge of the battery.

So a typical 18 volt, 1.3Ah P103 battery could be described as having 18v x 1.3A = 23.4Wh. The first battery I saw with a Wh rating was the P103, and it was rated 24Wh, so that seems about right. Here's a list of Wh ratings I've seen:

Holds charge 4X longer and reduces the need to recharge during long periods of non-use

This refers to the Lithium Ion chemistry's low self-discharge rate as compared to that of Nickel Cadmium. Say what??

Have you ever charged a NiCad pack, then put the charged pack on the shelf for a few weeks or months before you needed it? If so I bet you noticed that the pack was not fully charged when you went to use it. That's because Nickel Cadmium cells lose charge over time just sitting idle. So do Lithium Ion cells, but the rate of loss is 4X slower. So after sitting for a month or two unused a NiCad pack may seem nearly discharged while a Lithium Ion pack may still seem nearly fully charged.

Which batteries are compatible with my tools?

As far as I can tell, any 18v Ryobi battery will work with any 18v Ryobi tool. See the photos below to see each of the four battery types plugged into an old drill.

Do the serial numbers mean anything?

Yes! All Ryobi batteries (and tools) are stamped with a date code, and newer batteries have a serial number. The date code indicates when the battery was manufactured. The first two digits are the year and the second two are the week of manufacture. Some batteries may have one or two letters before the four numbers, not sure what they mean but my guess is the site of the factory.

0903 = "09" for 2009 and "03" for week 3
G0734 = 2007, week 34
CS0850 = 2008, week 50
CS12374N420709 = 2012, week 37 = Sep 2012

In 2012 Ryobi started printing a 2D barcode on each label which is encoded with the manufacturer part #, serial number, and model #.

I want to buy NEW batteries, but everything in the store is at least 3 months old! What's up with that?

It's perfectly normal to visit The Home Depot, check date codes, and find that everything on the shelves was manufactured several momths ago. Why? Let's not forget that Ryobi tools are manufactured in China. They're sent to the USA via boat, whose transit time can be a couple of months. While I have no knowledge of the actual process, I might expect additional delays. For example, the Ryobi factory probably manufactures a tool or kit in a "run" which lasts for several weeks. The items manufactured in the first week(s) may sit around until enough product has been produced to make a full shipment. Additional delays are likely at the shipping ports in China and in the USA, and of course some time is required for distribution. Tools manufactured for a special event sale (Memorial Day, Father's Day, Black Friday) may be held a little longer so they appear on shelves on the day that these sales begin. Without making a heroic effort, I doubt that new Ryobi tools can reach the shelves of The Home Depot in less than 2 months from the date of manufacture. Based on my personal observations I'd say that 3 months (or more) is typical for the factory-to-shelf process.

Hey! I just bought some new batteries and the date code says they're 9 months old! Is that a problem?

Not necessarily. These batteries are designed to sit on the shelf for months before sale. I have no hard data to support this, but I suspect that "new" batteries up to a year old or more are still 100% fine. Even still, when I go to The Home Depot I always check the serial numbers printed on the tool package before I buy (especially if the package contains batteries) and I'll always select the newest ones. Ryobi ships all batteries with a low charge, and all batteries self-discharge over time. When the voltage on Lithium Ion cells gets too low the cell begins to deteriorate. This phenomena doesn't really occur to NiCad batteries. NiCad packs are very resistant to problems when sitting on the shelf with a low charge for a long time. NiCad packs that are 18 months old or older may test lower than expected on the first cycle, but after 3-4 cycles they should recover back to like-new performance. Lithium Ion packs DO NOT like to sit idle on the shelf with a low charge for a long time! After 9 months or more on the shelf in the store or warehouse the deterioration of Lithium Ion cells can begin. That's why I would not purchase a Lithium Ion battery that's more than 9 months old.

Update 13-Apr-2010: Beware of new old stock P104 batteries! I've found that "new" P104 batteries taken from old kits (more than a year old) are often dead or operate at a greatly reduced capacity. I recommend avoiding the purchase of kits containing P104 batteries that are more than a year old. Batteries with a date code between and including 0821 to 0832 have had an especially high DOA rate. If you do purchase new old stock P104s, test them immediately using the "flashlight test" or other means to ensure that they are operating properly. Exchange or return the batteries if they're not OK!

Update 12-Jul-2010:
Last week I received some CS1018 batteries (1st week of May, 2010?), These are the most recent date codes I've seen. The behavior of the built-in tester has now changed a bit. Ryobi has now built a 2-3 second delay into the formerly momentary check-while-you-hold-the-button device. So press the button for just a moment and it stays lit for 2-3 seconds for you to read it. Not a big deal, but it's clear that Ryobi are continually changing their products.

The batteries in my new kit take a charge. Should I assume that they're all OK?

Absolutely not! The kit may have been new, and the batteries may take a charge, but that DOES NOT MEAN that your batteries are working as they should. I have purchased literally hundreds of Ryobi kits containing batteries, and I can tell you from experience that "New" does NOT necessarily mean that the batteries are in good working order, even if they take a charge! ALWAYS test your batteries soon after you open your kit! The sooner you test them, the greater the chance that you will be allowed to return/exchange your kit should you find a problem.

The easiest way to test your batteries is to fully charge them, then fully discharge them at a controlled, slow rate. A battery's capacity can be estimated from the length of time that it takes to discharge. The "Flashlight Test" is easy and accurate:

 A battery's capacity in mAh is 10x a flashlight's run time in minutes. 

(See the Battery Rebuilds, etc. page for a more detailed description of how to do this.)

I've found that the P104 is the battery most likely to have problems. This is especially true if the kit is more than 9 months old. It's unusual to find a bad P103 at all, and downright rare to find a bad P103 or P104 in a kit that's less than 6 months old (though it does happen). I would immediately return a Lithium Ion pack that tests below 80% capacity of its first charge. (At HD it's far easier to exchange a whole kit than it is to get a single battery from a kit exchanged, which is why I test batteries FIRST, remove the tools only after the batteries have tested good.)

If you buy a kit containing P104 batteries that's more than a year old, you should expect problems. Period. When you open the kit I suspect that the batteries may or may not take a charge. If they do, I'd expect their capacity to test below 50%. I know that Ryobi discounts discontinued tool kits when they're about a year old, and I suspect that Ryobi (and other makers who do the same) count on consumers not realizing that the batteries are no longer good. Let's face it, if the battery takes a charge and comes from a "new" kit, then the average consumer will think that it must be good, right? Wrong. I further suspect that some of the negative reviews given by first-time buyers of cordless tools who mention poor battery life and performance are actually consumers who purchased a kit containing bad batteries, and because they have no "new" reference packs to compare against they don't realize that this is what has happened.

As above, kits over a year old containing P103 batteries are also likely to have batteries which can no longer operate at full capacity. Case in point: I recently purchased two P542 chainsaw kits, each containing a P103 battery that was 70 weeks old. The batteries would not test over 900mAh even after several cycles. Otherwise they were fine. These old stock batteries wll never operate above 70% of their rated capacity. An uninformed consumer who purchases such a kit may simply think that this is the best a P103 can do.

The story with NiCad batteries is not the same as with Lithium Ions. New old stock NiCad packs seem to show a diminished power at first, but recover well after a few cycles. For example, I received two new old stock P100s recently that were 86 weeks old(!!). After the first charge they tested just under 1000mAh, but the discharge curves did not contain the telltale stairstep of bad cells. So I cycled them and retested, getting about 1200mAh the second time. I decide to go once more and got about 1360mAh. A few more cycles and they'll be fine.

Is there a "Quick Check" I can do in-store to see if the batteries in an old, discounted kit are still OK?

Maybe, and this would work only for Lithium Ion batteries (P103 and P104). Open the kit and press the battery tester on the P104. If it lights up to any color at all, the pack is probably OK. Carry a P150 Fuel Gauge with you into The Home Depot and use it to test P103 packs.

Why would this be an adequate "Quick Check"? I have a theory that I haven't quite proved yet, but well here goes. We know that the irreparable damage occurs to Lithium Ion cells only after the cell voltage has self-discharged below a certain threshold. And we know that the pack's self-protection circuit kicks in and disconnects the cells before the cells have discharged below this lower threshold voltage. So my theory is that if a pack can light up a battery tester, then the cells must not have discharged below the lower threshold yet, and must therefore still be "good". The pack could still be faulty (e.g., one cell has died while the others are OK enough to light the tester, or bad circuit board). But if the tester won't light up at all, the pack almost assuredly has problems and you should either pass up on the deal altogether or be prepared to return later with the faulty battery for an exchange.

How should I store my batteries when they're not in use?

This is the subject of much debate. I offer my opinions below based on my understanding and experience. YMMV

All Batteries
Keep them plugged into an IntelliPort Charger all the time, such as the P114, P115, P116, P117, or P126 SuperCharger. The IntelliPort Chargers are designed to keep batteries at a full charge without ever overcharging. If you don't have an IntelliPort charger, or (like me) have more batteries than chargers, then read on. DO NOT leave your battery connected to a charger while the charger is unplugged -- when unplugged the charger will actually discharge and potentially damage a battery pack.

It's also VERY important to keep your charger inside the house and NOT in the garage. This is because the charger will refuse to charge the battery if the ambient temperature is too high or too low. When the temperature is too high or too low, the charger's IntelliPort feature won't work and the charger can actually drain a battery that's plugged into it (possibly killing it) rather than maintain it. If you must keep your charger in the garage, then be certain to unplug your batteries once it's fully charged and set them aside. Ryobi manuals indicate that ambient temperatures must be between 50 and 100 degrees Farenheit for proper operation, and most garages will go outside of this range at some time during the year. (Note: I keep a P125 SuperCharger in my garage, and I use it year 'round. But I don't leave batteries plugged into it for long after they've reached a full charge.)

NiCads (P100):
NiCad batteries will degrade in performance if left idle for a long time with a charge on them. That's because dendrites form across the plates when in the presence of a charge. These dendrites are like little jumper wires that short out a cell. This phenomenon is often observed as "memory effect". One can usually "burn off" an accumulation of dendrites by putting a huge charge across the plates of a cell. Some folks advocate momentarily connecting a pack to a large voltage source to burn off dendrites. This does work, but also decreases the overall capacity of each cell each time it's done because it also leaves holes in the plate surface area (where each dendrite had been located) and cell capacity is a function of the total surface area of the cell. To avoid a buildup of dendrites, once can completely drain a NiCad cell and then short it out and store it in a cool, dry place to prevent a charge buildup. This works. Unfortunately this applies to the storage of single cells and does not translate well into the storage of a multi-cell pack such as the P100. In a multi-cell pack it's very difficult to ensure that every cell in the pack has been completely discharged, and simply discharging a pack is sure to result in the "reversing" of several cells as the pack's overall charge reaches zero. Cell reversing is generally more harmful than dendrites, so avoid this if possible. What does this mean for NiCad battery storage? Unfortunately not much, but I thought I mention it all so folks could get an understanding of what's going on in a NiCad pack like the P100.

The best advice I can give on NiCad pack storage would be to fully charge them before putting them away for storage. Then store them in a cool (55F to 75F) and dry place. I would further recommend that you discharge then recharge them ONCE PER MONTH. Mark your calendar if you need to. An idle pack will develop dendrites over time, so the best way to avoid this is to USE THEM periodically. I recommend using a flashlight, just plug the battery in and leave it on until the battery is depleted, then charge the battery and put it back into storage. It's a pain, but NiCads really don't like to be left alone for extended periods of time.

Lithium Ions (P102, P103, P104, P105, P108):
Lithium Ion packs degrade in performance when the charge on a cells goes out of the service range. This range is about 2.8 volts to 4.2 volts. Ryobi packs have five cells (P103) or five pairs of cells (P104) in series, for a safe voltage range of 14v to 21v. Sitting idle, packs can only discharge (slowly) so the best way to store these packs is to give them a full charge before storage. If left with a full charge, it should take more than a year before a Lithium pack will self-discharge enough to drop below 2.8v on a cell! I'd still recommend topping off the charge on an idle pack periodically (once every 6-12 months?) but there's no need to discharge them first like with the NiCads.

Update 02-Jun-2013:
I've changed my opinion somewhat on how to use and store Lithium Ion batteries, based on the results of studies carried out by Battery University. Of the various results, one can see that the number of cycles a battery can deliver can be increased significantly by not fully charging or discharging the cells, and by not storing the cells at extreme temperatures. I'm talking 2, 3, 4 or more times as many cycles per battery! Battery University reports that for maximum longevity, batteries in long-term storage should be kept at a 40% charge. This is difficult to achieve with the available tools, since a Ryobi charger will bring a pack to 100% charge. The older chargers will trickle charge packs when they reach a full charge, keeping them at 100% charge continuously and which will decrease the pack's recoverable capacity (by 20%/year?). But an Intelliport charger stops charging when a pack reaches a full charge, allowing the pack to self-discharge a bit. After a period of time the charger "wakes up", checks the battery, and tops it off. This behavior is actually quite beneficial to the longevity of the battery. But it still keeps packs near a full charge, which is not ideal.

If you're really serious about the longevity of your Lithium Ion batteries, then you should actively monitor your use of them. Try to avoid fully charging and discharging them. If you have a battery with a meter (or a P150 pocket meter), try to stop using your battery when you're down the the last bar. And don't allow the battery to reach a full charge -- pull it off the charger when the fourth bar gets illuminated. Finally, avoid exposing your battery to extreme temperatures. Keep your batteries stored in your house, not in your vechice or in the garage (which can get very hot or very cold).

Of course, for many of us the advice in the preceding paragraph will be very difficult to follow. To simplify: swap the battery you're using more often to avoid fully discharging any of them, get an IntelliPort charger or quickly remove your batteries from older chargers once the charge is complete, and always try to keep your battereis in the house (even if you kep the rest of your tools in the truck or garage).

Which battery pack do you recommend?

First of all, I recommend having two or more packs and a one hour charger if you're doing anything that drains a pack before you're done with the job. Then you can swap packs, put the drained pack on the charger, and get back to work. If you already have a P100 NiCad pack and a one hour charger, then getting a second P100 pack would be your least expensive option and a reasonable one.

I've now made the switch to Lithium Ion and I'm not looking back! I use mostly P108 packs, sometimes P103. If you have the need for more or new batteries and have the money to buy them, I recommend going with the Lithium Ions over the NiCads. I feel that per charge they do last longer than the NiCads and they can sit on the shelf between jobs without needing to recharge before use. And for single-handed tools the weight difference can be noticeable.

I find that I usually reach for a compact battery when I want to use a flashlight or a drill. I use a full-height battery with the reciprocating saw, canister vac, and yard tools.

I've made the switch to Lithium Ion. Any reason to keep using NiCads?

Well, there's no reason to throw out good batteries, period. But actually, yes, there might be some very good reasons to continue using NiCads. If you work in a very cold environment, NiCads might be a better choice than Lithium Ions because you can recharge them when cold. Lithium Ions will not take a charge if too cold. If you need to push your tools to the limit with maximum torque, then NiCads may be the best choice for you. That's right, if you need every bit of torque from your drill as it slowly crawls that spade bit through wet lumber, NiCads are for you. Why? It's because the Lithium Ions contain an internal protection circuit that cuts them off when pushed to the limit like this. NiCads do NOT have such a circuit, so you can push them as hard as you need to.

I don't measure 18 volts across my P108 battery. What's up with that?

Ryobi's newest batteries, the P107 and P108, are being marketed as "Lithium Plus". I'm not sure what this hype means, but they've apparently changed the internal circuit board design. As a result, the voltage at the terminals remains low until a load is detected. When used with most tools, you'll never notice the difference. But if you use a P740/P741 radio you may find that the radio doesn't come on when you press the power button. The quick fix is to press the battery's power level meter first, which briefly "wakes up" the battery.

With all other Ryobi batteries, a voltmeter across the terminals will measure the voltage of the pack. This can give an indication of the battery's charge level, much like the P150 Fuel Gauge will do.

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