We recently posted about the new and upcoming Flex Stacked Lithium batteries, which promise to deliver i) more power, ii) longer runtime, and iii) faster charging rates.
Full details still aren’t available yet, but new details have trickled in.
Flex reiterates that their new technology promises many advantages over traditional Lithium Ion batteries:
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- Significantly more power (watts)
- Significantly faster charging
- Significantly longer lifecycle
These are their exact words. Flex previously quantified the differences, claiming 20% more power, 25% longer runtime, and up to 50% faster charging.
These claims aren’t exactly new, but Flex also provided information as to the charge capacity and sizes of their new Stacked Lithium batteries.
Flex Stacked Lithium Battery Sizes
- 3.5Ah
- 6.0Ah
- 8.0Ah
Flex says their 3.5Ah Stacked Lithium battery is similar in size to a typical 2.5Ah battery, the 5.0Ah battery is similar in size to a typical 5.0Ah cylindrical battery, and the 8.0Ah battery is similar in size to a typical 6.0Ah cylindrical battery.
With traditional cordless power tool batteries, 2.5Ah is generally the limit for 5-cell battery packs engineered with 18650-sized battery cells, and 10-cell batteries are typically limited to 5.0Ah when engineered with 18650-sized cells. Stepping up to higher battery charge capacity sizes typically involves larger 21700-sized Li-ion cells, which leads to larger battery size and weight.
As Flex’s cordless power tool system is centered around a 24V Max battery form factor, their batteries are larger than typical 18V battery packs, but roughly similar to higher capacity 18V batteries.
With Flex Stacked Lithium tech allowing for a higher charge capacity in the same form factor as their standard batteries, users can benefit from a bump-up charge capacity and longer runtime without the typical increase in battery size or weight. This is on top of the Flex’s claims about greater power delivery potential and faster charging.
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Full details on Flex Stacked Lithium are not available yet, and we’ll update you as we learn more.
Note: Flex is a ToolGuyd sponsor.
Steve
Seeing this, I wonder what other sizes Dewalt has in their pipeline, because 1.7, half of the smallest Flex size, just doesn’t do it for me. I also wonder if TTi has these in the pipeline too as they used to be first when it came to battery technology.
Rx9
I would imagine that all the major manufacturers will roll a version of thus out if it is advantageous enough.
Steve
My understanding of the technology is that they can deliver lots of power really quickly but that means you really need high amp hours because it will drain faster, at least in applications that are taking full advantage of that potential.
MM
Whether or not you will need higher amp hours depends on how much work you’re doing. Let’s say for the sake of discussion that we’re talking about a power saw that normally gets 100 cuts on a given battery before you have to recharge.
Let’s say we swap out that battery for a Power Stack batt of the same ah capacity. The capacity hasn’t changed, so we still get that same 100 cuts. We just get to do them *faster* because the Power Stack battery can send more power to the saw.
If the job at hand required 100 or fewer cuts then we don’t need to swap the battery at all so the higher drain rate is moot.
If our job required more than 100 cuts then we have to stop to replace the battery. The difference is we have to do it sooner (by the clock) compared to a standard battery, but that simply means we’re working *faster*; we’re still swapping batts at 100 cuts, the only variable is how long it takes us to get to that point.
Things get more complicated when you compare a smaller capacity Power Stack battery versus a larger capacity “normal” battery. In that case you will have to change batteries more frequently than you would with a standard battery, but you are still working faster. Then the question becomes which has the bigger effect on your productivity: The time taken to swap batteries more often versus the productivity improvement from the tools working harder/faster. Assuming one has enough batteries to keep in rotation so there’s no time wasted waiting on a charger I’d say the productivity improvement would likely far exceed the time spent swapping batteries, generally speaking.
IronWood
Basically I imagine this will just be a new front in the battery arms race: more watt-hours, higher charge and discharge rates, etc. Maybe we’ll start seeing some new ultra fast chargers come out as well. I wonder if any of the companies not currently announcing pouch-type batteries are putting their efforts into solid-state batteries instead. I’m always happy to see innovation and competition!
Drew M
Milwaukee is already setup to take advantage of these packs with their “Super” chargers. Though, reality is that even R/C “graphene” doped lipo cells can really only handle 3C charge rates if you want the cells to last a long time. The bad news is that even higher rates don’t really translate to even higher charger completion times.
Steve
Additional thought: This is a big deal for Flex as the drawback to going 24V is larger heavier batteries making the tools larger and heavier overall. The pouches instead of the cells mitigate that problem.
OldDominionDIYer
I look forward to seeing some testing/comparisons with the standard batteries. I have doubts about the amount of improvement realized in real life situations. Not saying it won’t have improvements but they might also have other issues. That FLEX hammer drill is a really solid unit, I have used mine and am very satisfied. It is big and heavy but it is a beast. Bottom line is I am not sold on the battery shape change being all that revolutionary, but I guess we’ll see.
Mike
I’ll stay on the sideline for this one. I’ve had ‘pouch’ batteries swell in every electronic device I’ve owned – laptop, tablet, phone, and – yes – even a watch! Perhaps a nice side effect could be lowering of cylindrical battery prices 😉
Steve
I’m actually with you, I want to see how this goes for others for a while before I trust pouches in power tools. I’m concerned about the swelling. Dewalt claims they got something that will prevent the swelling and fire issues. I’ll wait a while and see.
Marko
“the 5.0Ah battery is similar in size to a typical 5.0Ah cylindrical battery”
Shouldn’t the first “5” be “6”?
IronWood
Both this and the DeWalt versions look pretty interesting. For me the faster charge rate could be a big deal for higher capacity batteries and greater power delivery could help with tools I still consider best as corded (grinders, miter saws, etc.) But for now I’m going to stick with my personal creed of never spending my own money on the first generation of anything. I’m just not sure the benefits would really justify the cost of replacing my current serviceable batteries or switching to a new platform and I’ll wait for some real-world reviews and testing (Stuart?!) before I get too excited. Of course, by the time I’m convinced to switch we’ll probably talking about solid-state batteries coming out and I’ll be in the same position!
Frank D
Some of our most expensive removable and built-in battery electronics have been with some high power pouch type batteries … all have lead to charging issues ( just like any battery ) and swelling causing fitment issues and then economic necessity to just replace the whole system, because either it was glued in, abandoned by the mfr or it went the whole brand went the way of the dodo. Of course removable powertool batteries are not comsumer electronics and computers, but having been through some brand ” shifts ” … I will stay with the tried and true.
Nathan
They’ve been in use for over 10 years if I recall. cell phones to laptops, tablets, and RC hobby batteries. I think what you finally see is that the longevity/safety requirements are captured well enough that they can be used in more demanding uses.
Yes we all know of the samsung handwarmer/campfirestarter issues. but note alot of other companies haven’t had those issues. The time it appears is right. I don’t however see these as high demand batteries. which seems to be the route SBD is taking with the dewalt pack.
I’m curious regardless. OH odd side question that’s been in the back of my head. Does this give indication that Chevon makes SBD batteries – or perhaps they use the same battery supplier?
Stuart
Brands usually partner closely with battery makers, but are not a direct part of battery manufacturing. There is no way to tell who the battery cell provider is for either brand.
For cylindrical batteries, you can often read the model number off the cell wrapper, unless the brand requires custom or unmarked wraps. It’s unknown if there will be any identifying information on the pouch cells. Besides that, pouch cells can be produced in custom shapes and sizes, and so they likely won’t be as “off the shelf” as 18650 or 21700-sized cells.
Brands tend to prefer the focus being on their battery pack tech and features as a whole – durability, charging rate, thermal dissipation, etc. – and so it’s a point most will be unwilling to openly discuss.
I only recall only one brand ever focusing on Li-ion battery cell maker, but they were also somewhat of a gimmick brand that needed the brand-name recognition.
In other words, I don’t have an answer to this, and it’s something I might never be able to answer.
Jeff
‘claiming 20% more power, 25% longer runtime, and up to 50% faster charging”
Where did you get “Significantly longer lifecycle” from?
Stuart
At the time, this was according to press/media materials. Currently, Flex lists “300% longer battery life” on their website as a Stacked Lithium battery feature/benefit. 300% counts to me as a significant improvement in longevity.