Ridgid 24 or 18V LI....newest technolgy?

[roadrashray]

When one is retired even if he keeps himself busy there can be periods when it's obvious he has to much time on his hands and starts to examine the minutia of things. Usually I am pretty busy traveling around the country in my full time RV, doing wild and scenic solo 100-200 mile canoe trips on the Missouri or Yellowstone in MT or backpacking out there near Doubtingtom in the incomparable back country of Zion NP in Utah. I like to work with my hands and will help friends with home building projects or work for fun and profit such as rehabing houses north of Woodenstickers in Portland,OR or building new custom houses south of Cactusman in Green Valley, AZ or working with my contractor newphew rehabing mid nineteenth century houses in Moravia,NY.
This year I purchased the full Ridgid 24V LI set and several of the MaxSelect tools and the Ridgid 18V LI compact drill when it first came out. It's been a fairly busy spring, summer and fall of projects so I have not dwelled to much on things regarding these tools. They have generally worked very well.
Recently I have had a few days of downtime and have started to examine or think about a few items that had piqued my interest, but while busy had not explored. I don't think any of these thoughts is really important in the grand scheme of things. They are simply the result of an old guy with to much time on his hands. Maybe some of you have thought about these same things and have some answers.
(1) LI Battery charge maintainence- I have read on this site several times that LI batteries are supposed to hold a charge for months. People have complained that the 24V LI seems to self discharge at a fairly high rate. Over time I have noticed mine self discharging at a higher rate than I would expect maybe even approaching the self discharge rate of Nicads. My 18V LI batteries self discharge at some rate also although since they have no "fuel guage" it is not as evident. I have noticed that after not using them for several days when I stick them in the charger they will charge for awhile.I did look at the owners manuals for both 18 and 24V tools and saw no claims in them about zero self discharge. My question is, is this a problem? Does this happen with other brands, Makita, Hitachi, DeWalt,etc?

(2) 18V LI or 24V LI Which is the newer technology? In the Ridgid world the 24V LI was their leadoff hitter with the 18V LI second in the lineup. I had automaticaly assumed that the 18V LI batteries and their charger were the newer technology. Several people have posted statements to that affect. While using these tools I have noticed several things that make me challange that assumption. The 24V has a fuel guage the 18V does not. I have not done a thorough comparison with other manufacturers however it seems like many of the newer batteries have the fuel guages. With the warnings expressed in many of the Lithium Ion articles about damage occuring from discharging that style of battery to low it would seem that the fuel guage would be more than just a convienence. The owners manuals for both batteries states "the battery pack will drop from full to zero once the full charge has been drained". Ridgid does not seem to be to concerned with how much we discharge the battery, possibly due to protection electronics in the batteries.
The 24V charger is totaly cold and quiet when not actually charging even with a charged battery sitting in it. This indicates digital technology to me.
The 18V charger however is warm all the time and emits a low hum even when the battery is fully charged. This indicates older analog technolgy with a transformer humming away. The charger even looks like the old Nicad unit.
It would seem that the 24V system is more completely engineered with state of the art design while the 18V system features indicates a more rushed and incomplete project using older technology.
There it is. I told you none of this was of any real importance. Just the musings of an old guy with time on his hands.

[Disaster]

Regarding #1, I have several tools and devices that run on Lithium Ion batteries.

I have noticed very different self discharge properties of many of them.

If, for example, my Panasonic tools batteries self-discharge, while sitting around it has to be at a very, very slow rate because they always have plenty of juice when I pull them out. In fact, I often don't charge them after this job or that because they never seem to need it.

One of the things that effect the discharge rate is the battery monitoring circuit. In some devices, it is in the device, not the battery and therefore will only discharge when the battery is in the device....sometimes only when the device is on. In other devices the monitor is in the battery but doesn't seem to drain much or at all.

If you think about it, a battery only really needs the monitor to work when it is installed in the device or charger. It would be simple to design a battery monitoring circuit that is only engaged, or on when the battery was plugged in. You could, for example have one of the pair of leads on the battery that only get closed when the battery is pressed into the socket. I suspect this is what some manufacturers do.

It is more complicated when you design a battery to work with existing devices. The battery needs low voltage protection so you need some type of circuit on it but you don't have the advantage of having spare connectors to play with. I can still imagine several designs to get around this but it doesn't appear Ridgid was concerned enough about self-discharge to think about this.

I haven't noticed the self discharge of the 18 volt Lithium cells...but I haven't had them that long. If they discharged as fast as the 24v ones I suspect I would have noticed so perhaps they use a lower energy circuit.

Relative to #2 I don't think the fuel gauge is high technology...especially the ones that are used in tool batteries. Someone posted that the one on the Ryobi battery is a simple voltage gauge and not a good indicator of actual charge. The one on Ridgid's own batteries also seems a little off. I notice batteries go from 3 to zero bars much faster than they go from 4 to 3. They also quickly jump to three or four bars early in the charge cycle.

As far as the hum is concerned both of the Lithium Ion chargers, are lightweight which means they must use switching power supplies (same technology used in computers and much more efficient than the heavy transformers formally used) Switching power supplies can hum. The 24 volt one is probably just designed or packaged in such a way that the hum is dampened or less apparent.

Both batteries contain circuits to protect the battery from overdischarging.

[roadrashray]

Regarding #1, I have several tools and devices that run on Lithium Ion batteries.

As far as the hum is concerned both of the Lithium Ion chargers, are lightweight which means they must use switching power supplies (same technology used in computers and much more efficient than the heavy transformers formally used) Switching power supplies can hum. The 24 volt one is probably just designed or packaged in such a way that the hum is dampened or less apparent.

.

Disaster.....You have both the 24 and 18v LI sets. Compare the heat from the
18V vs 24V chargers after the batteries have completely charged and chargers are in maintainence mode. The 18V feels just like the old Nicad charger and is very warm all the time while the 24V is cool.
There is no real reason to this exercise. I had read on some other sites about some of the market research regarding the evolution of lithium ion Power Tool development. In typical early product release fashion everyone tried to differentiate by releasing unique voltages ie: DeWalt 36V, Ridgid 24V, Milwaukee 28V, Makita 18V, Bosche 36V et all. Quickly they found the same truth as with Nicad which is that 18V is the optimum size taking into consideration the power, weight, cost, matrix. There is now a rush for all manufacturers to bring 18V LI tools to the market.
This relates in part to my theory as to why Ridgid was planning to release a 3Ah battery first. This is evident because 3Ah is the 18V LI battery shown on all the MaxSelect tool boxes. My theory is that due to limited LI battery manufacturing capacity by the time Ridgid ordered batteries for the 18V LI drill all the 3Ah capacity was sold for the immediate future to Hitachi, Makita, and others. They were forced to take the 1.5Ah size which was freed up when Hitachi and Makita switched most of their requirements over from 1.5Ah to 3Ah. Thats why the Ridgid 1.5Ah battery looks like a quick and cobbled production including the cheap and fast stick on label on top of the battery.
Don't get me wrong, I like my Ridgid 18V LI compact drill very much and it is very usable even with the 1.5Ah batteries. As an old marketing management type myself I believe I can see all the signs of a product that was rushed to market with some shortcuts made.
Review of Ridgid 18V LI Battery situation......

1-Obvious Ridgid intended to use a 18V LI 3Ah battery because that was the size printed on all the packaging of the MaxSelect tools.

2-Ran into a problem due to shortage of LI battery manufacturers and a rush of other tool manufacturers developing 18V LI products which forced Ridgid to purchase 1.5Ah batteries as a stop gap.

3-This tight market problem is the same reason they were forced to modify the Nicad charger for use with the 18V LI batteries and have some old technology on board instead of designing a new charger like the 24V LI.

4-Further proof of this last minute switch is the fact that the 18V LI drill packaging, user manuals and batteries do not show the battery capacity anywhere. This is very unusual in the power tool market.
All of this is enough to set a conspiracy therorists heart to pounding. I say conspiracy because of course Ridgid is never going to admit to this because to do so would open them up to some financial liability for compensating all you rabid slatherering 18V LI drill buyers who were expecting 3Ah batteries and whose lives were devastated to find they were given only 1.5Ah.
This is all an academic exersize of course and has no real value but was kind of fun....Ray

[Frankiarmz]

So Ray, what do you think are the chances of Ridgid getting around to making that 3.0 AH 18 volt lithium? I think it makes sense to make such a battery to properly power the max select tools and the original 18 volt nicad tools some us have. Thanks for the input.

[roadrashray]

Although some of Ridgid's management decisions have seemed a little strange lately I am confident they will offer a 3Ah battery at some point in the near future. They are a large company that is a dominant player in several segments of the construction industry. Their parent company (TTI) has a strong history and their siblings (Milwaukee and Riobi) are both serious contenders in the power tool marketplace. I believe there is synergy within all that mix which would indicate that Ridgid will work through it's current issues and get things together. It's also important to remember that Ridgid is the Home Depot house brand though we all recognize they have their own management and marketing problems.
Oh well, they either will or others will replace them.......that's how it works.

[doubtingtom]

I'm too inexperienced in this .... and 18v would seem to be the 'mainstream' number. My only hands-on comparison was with Ridgid 24v (Hammer Drill and batt attached) and Milwaukee 0824-24 V18 (same combo). There was very little difference in size or weight, although some source has stated that the V18 voltage is actually closer to 20v. I guess my point is that in this case 18v did not seem to offer much advantage (perhaps slight disadvantage) vs 24v.

Tom B