Question on using Milwaukee Fast Chargers

[Firefighter1406]

Alright,

I have 2 batteries 12ah M18 batteries. They both came with fast chargers for the batteries. I don’t remember the specs however I remember from the old DeWalt No-cad batteries I had that fast charging isn’t good on the batteries. I know these are newer technology with the lithium ion batteries. However I feel the same applies to it not being good on the battery.

So the tools that I have that use the 12ah batteries are both high demand so they are gonna wear out fairly quickly. I have Charger these batteries with a standard charger and it has taken over 3 hours. The fast charger will do it in about half of that.

How much of the battery life at I ruining by fast charging. Is it worth it? Or being the batteries cost a lot not worth it? I mean if this is something that slowly happen over 10 years that’s one thing. But if fast charging these batteries shorten there life a lot I might hold off on doing it.

Anybody have experience or knowledge about this area?

 

[kctyphoon]

I sincerely doubt you're doing any damage at all. For starters, considering the chargers are designed by the same people that designed the batteries so they work together, and they warranty both of them. Secondly, Milwaukee just announced or released an even faster charger called the super charger, FOR those batteries and any new HO or HD pack (whatever they call em, the ones using the newer bigger cells). Lastly - I wanna say (maybe someone can verify) that the chargers aren't just dumping current into the packs. They are being monitored, and the rate of charge slows as the battery becomes close to full.

Every major battery/electronic company has some form of this. If Tesla can supercharge it's cars, and phone manufacturers like Samsung and Apple can do it on cell phones, I don't think u have anything to worry about.

My batteries LIVE on their chargers. (The ones I can fit on there anyway). For months at a time sometimes. These new lithium chargers aren't what was used on those old nicad packs. I believe Milwaukee said their new charger can give you up to 60 cuts with a saw, if you give a dead battery just 5 minutes on their new charger.

Here's the truth of it all though. Do whatever you want. There's no way you'll ever be able to produce a controlled study to compare the life of a battery vs a slow and fast charger. There's too many variables, it might take years to get results. All I can tell you is I haved a lot of batteries and I think I've only seen 1 M18 pack go bad out of the 30 or 40 I must have used between work and home.

I'd love to have some 12.0's but I have 3 9.0's as it is, and a pile of smaller ones. The handheld blower and string trimmer are the only tools I really run batteries down till their dead, (at home) and I've never run out of 9.0's yet.

 

[Firefighter1406]

I appreciate the input. I know the charger technology has come a long way as well. Just nervous at the cost of the batteries that’s all. With the big gen 2 blower and the super sawzall even with the fast charger it’s tough to keep up.

 

[Lisamelting]

I've used 9.0 high demand batteries on my 1/2" high torque impact every day for about a year. I keep one on the fast charger and one on the tool. When the battery on the tool shows 1 bar of power left I swap it out with the other one. I don't feel that I'm doing them any harm and when they finally wear out I'll replace them.

 

[mobiledynamics]

off topic or on topic.....if I've have a few batteries I've used hard and are drained, I still resort to the original charger. I like the low and slow. Some batteries I've put on the rapid charger and IMO, it was a bit too warm for my liking (9ah)

 

[reptilezs]

just use the slow charger and only the fast when you need it.

 

[2manytools]

I appreciate the input. I know the charger technology has come a long way as well. Just nervous at the cost of the batteries that’s all. With the big gen 2 blower and the super sawzall even with the fast charger it’s tough to keep up.

While discharging and charging are two different things, still think about the fact you can drain that 12ah on the blower in 20-25?min of continuous use (i only have gen1), but even on just the rapid charger it will take over an 2 hours to charge. So the current going in is still much lower than what is possible to take out of it.

The only time I see one shortening the life of a battery pack, is putting a low capacity pack in a tool it is not really up to the task & draining it as fast as possible. Like the 2ah in the blower circular saw. Yes it will power it, but the draw on that pack is far from ideal.

Related question. I know it is easy to a pack that is obviously defective, due to blinking light or such, but what about run time? Say I know my 12ah battery doesn't run as long in 3 years, does anyone know what kind of drop would get Milwaukee to swap it out? Only test I can think of running well would be on a light .

 

[Handyandy23]

off topic or on topic.....if I've have a few batteries I've used hard and are drained, I still resort to the original charger. I like the low and slow. Some batteries I've put on the rapid charger and IMO, it was a bit too warm for my liking (9ah)

Don't they have some kind of thermal overload built in though? To avoid overheating?

When it comes to stuff like this, I tend to trust the designer and manufacturer of the product. If Milwaukee sells the battery with that charger, that means they've been a lot of testing and engineering into it. They know what works and what doesn't work.

No offense to anyone here, but you don't know how these batteries work or a lot of the science behind them. Why would you question those who do and do this as a living when you have no basis to doubt them, other than you're worried?

I know what I know, and I know what I don't know, and if someone that does know is giving me information about a topic I don't know about, I have no reason to not believe them. Milwaukee isn't in the business of frying batteries that they have to warranty out.

 

[minke]

Don't they have some kind of thermal overload built in though? To avoid overheating?

When it comes to stuff like this, I tend to trust the designer and manufacturer of the product. If Milwaukee sells the battery with that charger, that means they've been a lot of testing and engineering into it. They know what works and what doesn't work.

No offense to anyone here, but you don't know how these batteries work or a lot of the science behind them. Why would you question those who do and do this as a living when you have no basis to doubt them, other than you're worried?

I know what I know, and I know what I don't know, and if someone that does know is giving me information about a topic I don't know about, I have no reason to not believe them. Milwaukee isn't in the business of frying batteries that they have to warranty out.

IMO you are right when engineering makes the decisions. When marketing overrides them all bets are off.

 

[Crazyjake8493]

I wouldn't lose any sleep over it. If you're really worried just charge them on a standard charger if you have time, and if you're in a hurry use the rapid charger.

I typically just throw my 9ah or 12ah batteries on the rapid chargers and the 5ah and smaller on the regular chargers just out of habit. But I've charged even my 1.5ah M18 and 2ah M12 batteries on a rapid charger several times with no ill effects. I imagine by the time any long term damage was done I'll be looking to upgrade my batteries again anyway.

 

[Ign]

I don't over think it. I went Rapid Chargers 100% when they came out.

But then I have so many batteries and am always acquiring more thru deals, sales, promos...that I don't have a need to preserve one forever.

I do like that compact batteries charge seemingly instantaneously on the Rapids

But basically, life is too short....find something else to worry about

 

[Firefighter1406]

I appreciate everybody’s thoughts. You guys make some good points. I guess only time will tell.

 

[DerekV]

Slow chargers for me. I have 4 of them and a ton of batteries so I never feel like I'm out of power. I'd rather save the stress on the battery for doing the actual work, not charging up. Slower charging is better for lithium batteries, that's a fact. How much better is a matter of the pack in question. I do sympathize with the "life's too short" thing though. Milwaukee packs are tough hell. I just personally prefer to give them the slowest charge I can give them. Helps me sleep at night

 

[Ign]

4 Rapids in the shop, been that way for over 18 months (which I realize isn't enough data, yet).

edit: more like 2 years, time flies!!

I dunno, I charge everything M12 and M18 there, leave 'em on the chargers...in the cold...in the heat...

everything works fine so I'm worrying about bigger things

 

[Ign]

I've also got 2 Rapids in the house...in the winter our compact 3.0 M12's really get a workout with heated gear....I have had TWO 3.0's mysteriously fail but I assumed it might be a problem with the relatively new compact 3.0's

But in both cases Milwaukee replaced under warranty, which is another reason I don't worry much...all your batts are basically guaranteed for 2 or 3 years.... although they were SLOW in turnaround so if you only own a couple of batts and need them for work that *****.....

me, I could send in half my batts and still have enough to build an apartment building

 

[sparky 1971]

I can't say anything for the 12.0 batteries because I don't have any. I have four 9.0's, tried to charge one in a regular charger and it wouldn't work. The charger blinked the code for a defective pack. Put it in the rapid charger and all was well. I never tried another 9.0 on a slow charger again, so I don't know if it was only that particular battery or all of them.

 

[Black300zx]

IMO you are right when engineering makes the decisions. When marketing overrides them all bets are off.

Bingo. Many times engineers are designing around requirements which are established by other functional groups. They have to balance features and performance that are desirable to the end user with manufacturability, profit, etc.

If the product will have a 5 year warranty, they sure as heck better not design a high speed charger that will increase the failure rate within the first 5 years. That doesn't, however, mean that the high speed charger won't reduce the typical useful life from 9 years to 6 years.

I have no first hand experience with Milwaukee tool (I hope to soon) but as an engineer i know that the viewpoint of "the designers engineered them to work together" doesnt neccesarily mean there isn't a downside to useing a higher charging rate. It just means that someone established that in the intended use case the benefits outweigh the costs.