Charger changes, update for better battery life

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Being a sponsored remote control racer has some bonuses and downfalls:

1) I found the April 1st ad hilarious, but don't get me started because I have ideas ;)

2) I tend to know more about batteries than I ever wanted.

The 30 minute (and longer charger) that comes with the mower should have two modes to maximize the life and capacity of the battery.  You are actually costing yourselves quite a bit of potential money due to warranty replacements because this was not properly implemented.  The charger should have two buttons/options when a battery is docked 1) maintenance charge and 2) run charge.

1) "Maintenance charge" (or storage charge) should be for after the battery is used for the day.  
2) Just before use, you would activate the "run charge", doing a full battery load.  If you set your cutoff for the maint change at about 50%, this would only take 15 minute to do, roughly the time most people probably spend doing a quick trim job or something like that.

As you should be aware, optimal battery storage for this type of battery is around 35-50% charge, the cooler the better.  Storing them drained after use or charging them to full is actually quite hard on the battery long term.

So I'm basically left with a situation where after I run, I need to put the battery on the charger for probably 5-10 minutes and them remember to go pull it off before it fully charges.  This is the only way to properly and safely optimize the life of the battery with your system today.

I just picked up the mower last night and look forward to hopefully a blower, trimmer, and bladed edger in the future... but this seems like a pretty big "oops" in the design department for something that is this technically advanced.
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Eric

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Posted 5 years ago

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Dominic49

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the battery will actually go into a storage mode after 3 months of standingthis drains the battery to an optimal storage level of 30%
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Eric

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That is all well and good, yet nearly completely pointless.  For most people 3 months is 1/2 or 2/3 into winter. This is preventive maintenance that should occur after nearly every use, not once a year.  For example, when we race, you charge a pack the day of the race use it, then put it down into it's maintenance/storage voltage/capacity until the next weekend.  The same goes for these units, nearly identical technology.  Keeping these batteries either drained or at 100% charge will drastically diminish the lifespan and possible cycles of the battery.  Currently other than manual intervention, 100% or whatever capacity it was left at after running is the only option offered.

So some quick research on li-ion, li-po, etc battery storage temperatures/voltage/capacity and you will see what I mean.
(Edited)
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Derek Smith

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I fly electric radio control planes for a hobby and totally agree with the OP. Planes have slowly been making the transision from gas to electric ofer the last few years. I been charging my Ego packs when I am done for the week until I see the 50% light flash and then pull them off. Just something people theat are used to working lithium batteries hard are used to doing.

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SCDC, Champion

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To the OP.

You are correct, but from my reading you will get best battery results if you do not drain the battery all the way,  store inside in a cool place, and charge the battery to roughly 50%.  Check out this link, the number of charge cycles falls drastically with temperature and full charge drain cycles. 

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

It's a good read.  I would love to see an option on the charger that automatically trickle's a battery down or up to 50% when it's in the holster for more than 48 hours.

Thanks for the good read.

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Blue Angel, Champion

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Eric, I found the link to this thread from your mower review. I posted this response there as well:

==========

I just came across this older thread and wanted to shed some light on the battery maintenance issue.

Eric, you are correct; lithium cells do not automatically discharge to a proper storage voltage. However, the Ego battery PACK is designed to discharge its cells to a proper storage voltage after a sedentary period of one month. It is not the CELL that performs this action, it is the pack electronics that do. It is a very sophisticated system, one that earned my business after researching.

Knowing, like you, that cells are better stored in a semi-depleted state, my personal approach is to charge the pack just before cutting the lawn and not recharge it immediately afterwards. In my case, this drains the pack to roughly 50% capacity before storage and the pack only sees a full charge level for a short while before mowing.

==========

While you are correct about optimizing battery life by setting the charge voltage after use, I'm sure if you plotted the benefits of different battery maintenance and cell optimization methods, you would see a "bell curve" type of distribution that would indicate, for the average user, the Ego "1 month" method gets you most of the way there compared to the alternative of leaving your packs fully charged for the whole winter.

Ego have done a pretty remarkable job of Engineering this battery system. I'm sure one of their goals is to make it as simple and convenient for the average consumer as possible. Part of that would include a "fool proof" battery charging regimen.

While you can technically argue that the system isn't 100% optimized, you must also admit to the reality of a customer base who know little to nothing about battery cells and cannot be trusted to maintain them. Your two-mode charger idea IS a good one, I agree, but it would add cost, complexity, and maybe not much ROI (Return On Investment)? I trust the Ego team have done their homework.

Off topic, I was into RC when the "good" packs were the ones with the yellow 1500 mAh Sanyos... yeah, the 1.2V sub-C's. How times have changed! A single 18650 can pack as much juice now as a six cell pack back then.
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Roger Leahey

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I'm 100% with Eric. I would gladly pay more for a charger as Eric describes. Lawn mowing is hard enough; I would pay for more "ease of use".
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Roger Leahey

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After reading about EGO battery maintenance, I would say that I am never going to use the “turbo” setting.  Isn’t a high drain rate and associated heat detrimental to battery health? I suggest ECO do away with “turbo”. Just have one setting – “high”.

If you encounter tall or wet grass that taxes the mower, just do  what people with motorized lawn mowers have been doing for thousands of years – just go slower.

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Michael

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Or, like I do when I allow my grass to get very tall I cut a thinner swath of grass on each pass. It takes longer because you have to make more passes, but it gives the mower a better chance of mulchifying the long grass and pushing it into the bag

I've been using a Toro GTS recycler with a Suzuki motor I bought back in 1987, and even it will not handle some of the long grass I have mowed with it unless I cut a thinner 12" swath instead of the full 21" swath. Since it is self-propelled I just keep it on the lowest speed and it does fine without needing to slow down further.

Now some might say doing this leaves an odd pattern in the lawn, but hey - that's the price you pay for letting it get that long!

My first mow this spring was delayed by several weeks because of the constant weekend rainfall, and by the time the grass dried enough to mow it was out of control. Some blades were probably a foot tall because my neighbor decided to plant rye grass over the winter and it spread into my yard like a weed.
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Blue Angel, Champion

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Roger, you are correct. All else equal, a higher rate of drain will shorten a cell's expected life.

I will say, however, that Ego has done a fantastic job managing heat. Heat during high discharge is one of the main things that damages cells. Ego has a pack that goes far beyond what any other power tool company has done with regards to thermal management, as far as I know anyway.

Their "Keep Cool" technology is actually an individual cell wrap consisting of phase-change material. In a nutshell, this material absorbs immense amounts of heat while maintaining a stable temperature. This is why I can use the small 2.0Ah battery to cut my lawn and the pack is not even warm to the touch when I pull it from the mower. In that application the pack goes from fully charged to fully depleted in less than 25 minutes of steady mowing.

When I saw that I was very impressed, and gained a lot of confidence in the Ego packs. True, using the blower on Turbo will drain that pack even faster, but unless you hit the turbo button and don't let off until the pack is dead I'm sure you have nothing to worry about. The blower moves lots of air on High, Turbo is only for those situations where you've got a pile of heavy material to move.
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Blue Angel, Champion

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For those concerned with the longevity of the cells in their power tool battery packs, here's a great article to read:

http://www.greencarreports.com/news/1...

The Teslas are not really relevant here because their battery packs are so large that the average person doesn't deplete them on a regular basis, rather they use a small portion of the capacity every day and may or may not charge the car every night.

The Leaf, on the other hand, offers some relevant insight. Nissan guarantees the battery will have 70% of its capacity left after five years or 60,000 miles. For a car with a relatively small battery capacity, being depleted and charged on a daily basis, that's promising.

Using the Leaf duty cycle as a comparison, consider mowing your lawn every day, year round, for five years straight. That's enough grass cutting for the average joe like me to keep their lawn trimmed for 14 years! I cut the lawn about six months/year, once a week.

Sure it's not an accurate apples to apples example, but it proves a point. No, the Leaf doesn't deplete its pack as quickly as the Ego mower does, but the Leaf doesn't have cell thermal regulation like the Ego packs do, either, and high ambient temperatures have caused lots of Leaf battery failures. If my Ego packs still have 70% capacity after even 5 years I'll be thrilled.

Just some food for thought. :)
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Jennifer VandeWater, Community Manager

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Official Response
We appreciate all of your interest in new EGO products! Please understand that it takes time to design, engineer and test products to our exacting Power+ standards before we are ready to release them. Check here for announcements--you’ll be the first to know! 
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Eric

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There are a few things here to note that some may not know and just as a reminder.  1) There is an actual power curve on lithium batteries.  It is nowhere as drastic as batteries of past, but it still exists.  In other words, old batteries had a pretty straight 45 degree angle downward in terms of voltage and use.  So the batteries only run at peak when fully charged and loose voltage output (in addition to remaining capacity) as they discharge.  Lithium runs at much higher volts for much longer, but still has a curve of power.  2) All the maintenance items I stated earlier including temperatures, how to store batteries, what capacity/voltage should be used, etc.

Well, since some didn't believe me, I ran some tests.  Note, there are some variables here including amount of moisture in the grass, age of the battery, height and thickness of the lawn, sharpness of the blade, etc.  However, my conditions are quite consistent and the results are clear enough that these variables are clearly not part of the discussion.  So the information:

I maintained the battery scientifically the correct way last season and the first month of this season.  That means maintaining proper temperature.  Never letting it sit at full or discharged state (prefer 40-50% roughly).  etc.  Over this period, the discharge curve (occasional voltage check as the battery is discharging) remained the same.  As well, total capacity was decreased about maybe 2-3%.  This is about normal and within tolerances of a lithium battery.

The last few months, I have been following the "normal user" and EGO formal or informal recommendations for battery maintenance.  Letting it fully charge on the charger and letting it sit, allowing it to remain partially discharged (sub 40%).  Storing in the greater temperatures than I typically would, etc.  As a result, I have lost about 15-17% of the capacity of the pack, and the power curve has changed quite a bit as well.  The output voltage now drops quicker, resulting in much more frequent yellow alarms as I mow.  I have a video of a stretch of about 30' of grass, where the battery is at about 40%, the grass has already been mowed, where i go over it again and the yellow kicks off 5 times.

So the result, do your research on proper battery maintenance or face the scientifically expected results.  I hate to say told ya so, but told ya so.  Hopefully EGO updates their chargers and documentation to reflect the correct way to deal with these cells.  The rest of their design is fantastic down to the way they laid out the cells inside the battery, why they ignored the obvious I still do not know.
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Tom Magruder

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Assuming that a battery is maintained "scientifically" as described, and taking into account EGO's excellent heat management technology, do you anticipate that their Fast Charger will noticeably shorten battery life and output vs the standard charger?
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SCDC, Champion

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Quite honestly, it is all about heat management.  If you use the quick charger in a cool place like in a house, then the loss shouldn't be much.  The quick charger generates more heat in the cells, thus does shorten the life.  If you keep it cool while charging, it sort of negates that affect.  I keep mine in front of a fan, in my house.  House is almost always 70 degrees F with <45% humidity.
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Blue Angel, Champion

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My personal approach is to use the standard charger since, all else equal, charging slower will be easier on the cells.

But, as SCDC has pointed out, the negative effects of fast charging are largely negated with Ego's fantastic thermal management. I would not feel that the fast charger is doing any harm to my packs.

The "slow" charger, after all, is still plenty quick and is faster than most of the competitions charging options. Check out "Ego vs Echo" on YouTube for some excellent videos showing how well Ego's battery system is designed vs the competition.
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SCDC, Champion

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You'll be using that quick charger when you get your snow blower :)
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Blue Angel, Champion

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Absolutely!!! I only have a 2 car single lane driveway (plus sidewalk), but given the nature of how terribly heavy snow can be, I'll probably be into more than one 4Ah battery to git-r-dun after any kind of significant snowfall. We'll see. Maybe they have some tricks up their sleeve as far as efficiency goes.

Ah, the word "when" has such a nice ring to it! I only hope the edger crowd has a chance to replace the word "if" with the word "when". :-)
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TheAtomTwister

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You know, I've been thinking about modding my EGO and Kobalt packs by putting little voltage indicators on each of the cells in the pack on the top of the pack and having on the bottom for the 80V and on the sides for the 56V a way to quickly change out cells.  I think I'm going to build a custom pack for that, probably a backpack battery with a 56V piece for EGO stuff and an 80V piece for Kobalt and Greenworks stuff. It would have a pretty interesting set of systems in it... I don't know. I'd really like to be able to switch out cells at will, but that's more an idea just for me.  I don't know how that'd be any use to EGO...
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Blue Angel, Champion

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I'm not sure how much tampering an Ego pack will tolerate before sensing something amiss and shutting itself down...
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TheAtomTwister

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It depends on what'll shut it down. Even then, all else fails, gut it, make a new system to replace the old one with, and it'll work again, this time, with your technology.  Then paint it your favorite color for laughs.

I'm going to guess that it shuts down when the voltage falls beneath a certain point, and I can confirm that with the voltmeter... I'm more interested in messing with the Kobalt in that way than I am the EGO, though. The box battery design is a little more accommodating for that kind of stuff.  I'm just gonna take a look at the insides of the Kobalt and see if it can tolerate 88 volts, and I'm going to make a tweak that will allow for the pack to run like normal, but for it to add cells to its circuit when the cells are inserted to the pack.  I sort of want to leave the EGO pack alone just because it seems like it will be more of a toad to work with than will the Kobalt.
(Edited)
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SCDC, Champion

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+1 for me responding to the wrong post.  sigh.  Atom.  I don't think a voltage meter would be much use.  I guess if you are just curious, then what the heck.
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TheAtomTwister

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Well, it would work for seeing when the battery shuts down if it is based on voltage, and it certainly appears to be... I work with lasers quite a lot, and one thing that I can't help but notice is that after the battery really begins to lose charge, the laser dims out. I can then open the circuit for a little while, then close it again, and I get a brief flash and the laser loses power again, this time more rapidly. The voltage comes back, in essence, only for remaining charge to be more easily drained... or so it appears. I noticed something very similar with the EGO pack. When I drain it by running the blower on turbo until it shuts down and the light flashes red, I can just let it sit for a bit, and I can then put it back into the blower and it'll run for just a bit longer, but then it stops and the battery flashes again. It seems as though the Li-ion cells (IMRs), like ICRs and NiMH cells, regain a bit of voltage just by sitting even though they gain no more charge. I'll confirm with the voltmeter, but I am pretty sure that the pack shuts down after the voltage falls below a certain threshold to prevent overdischarging of cells, which would shorten the cells' lifespan.  I can confirm this to be the case by using the voltmeter to see exactly what the voltage of the pack is right at pack shutdown.  
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Blue Angel, Champion

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Great post, Eric!  Keep the data coming!

Just curious, how are you measuring the capacity of the pack?  Are you just measuring voltage before/after mowing, or do you actually have a discharge bench rig set up?

I've often considered hooking up a volt meter to my mower so I can see what's going on while mowing.

Just a comment regarding the power curve of the cells.  I believe all Ego tools have regulated supplies which keep power supply to the tool constant as the battery voltage drops, pulling more current from the battery as the pack discharges.

I have noticed that my mower's performance doesn't change one bit until the red light comes on indicating the battery is getting low.  At that point I believe the pack's voltage drop under load is great enough that it can no longer maintain the motor's output.

However, I can take that same battery and put it in my blower and the battery light is green again due to the lower power draw in that application.
I love your idea of adding a volt-meter!  That would also give a more accurate run-time analysis and I could be sure to not run the packs down so low, switching them out at 50% let's say.  Tapping into the wiring would void the warranty, so I won't do that, but maybe in five years I will.  
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Tom Magruder

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I ordered the Fast Charger in part for the LED readout that gives a 50% charge point for damage free battery storage. I plan to charge my packs mostly with the standard charger, run them down on the job, then 50% charge them for storage with the QC.

I'm hoping the EGO chainsaw is going to replace my Italian made Efco Arborist 132-S for most of my climbing and limbing tree work. I really hate cranking a saw when aloft. Got the chainsaw bare w/ 2.5 A/H pack to maximize run time at minimum weight, this pack being same weight as the 2.0. My blower battery will serve as my "reserve tank" that I will carry in a belt back when needed.

If EGO has the foresight to make a battery extension cord that allows their chainsaw (& other tool's) battery pack to be worn on a belt, they could quickly create the lightest arborist saw on the market and give the gas guzzlers a serious run for their money.   

All I want for big kid Christmas...an EGO battery pack extension cord that doubles as my chainsaw lanyard (with a saftey breakaway connecter) plus a battery belt pack with cooling tech and elastic expansion straps to snug fit any size pack.
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Jennifer VandeWater, Community Manager

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Great idea Tom!  We'll be sure to consider your extension cord idea.  That might be a good idea for ideal weight distribution too!
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Blue Angel, Champion

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With the introduction of the 42 cell 7.5Ah battery, a battery extension begins to make a TON of sense. Tom mentions some excellent points, and welding a chainsaw single handed would be example #1.

It would also benefit anyone wanting to use any of the lighter Ego tools with the larger packs. The blower, for example, would be quite a strain on the wrist and shoulder with the 7.5Ah pack, but that pack would give someone the run time required to clean large yards. Tethered to your belt by an extension cord, that battery would no longer be a burden.

Sort of the same idea as a backpack battery, but using only one pack.

Can I add to this idea and suggest a belt worn holder that simply carries a spare Ego pack, for those who need to work away from their charging station? This would allow using a 2Ah pack for good ergonomics with a second one in reserve.
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TheAtomTwister

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Especially if you want to add a 15 to 30Ah backpack battery to the mix like Husqvarna did :D Tom, your idea goes splendidly with a backpack battery. I read somewhere on the forum that EGO was working on several tools, and of course the only one that I know of to have had a major announcement on it was to SCDC's disappointment a snowblower and not an edger, but I'm betting that SCDC will see his edger... or weedwhacker attachment... some time soon. SCDC, you should do that, just get the EGO string trimmer and do some work on it to adapt it for edging work.
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Tom Magruder

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The battery belt pack that goes with an extension cord could be sewn from a heavy duty mesh material to keep the battery cool. An internal foam spacer between battery and body would pad the pack and prevent human heat transfer. Carried this way, the cell might even stay cooler than when it is attached to motorized tool?

Regarding battery charge monitoring for ideal daily storage, how hard would it be to adjust the programming on (an improved) pack's charge indicator that now blinks red, orange, green, so that it signals in only orange at 50% when charging (and also when the test button is pressed) to indicate that this Smart Cell has reached (or dropped to) an ideal storage and recharge point of 50% charge?

This would be a great, green way to extend battery life and keep more heavy metals out of landfills. Informed consumers could choose the Twin Pack Smart Cell option to always keep each cell at an ideal 50% charge, thus maximizing their product investment.
Ideal recharge/re-store timing also effectively cuts battery charge time...by half! 
EGO would see an increase in pack sales as existing customers upgrade to the SCTP system.

Offer an EGO-ECO Recycle/ Replacement program where everyone who drops off an old pack for recycle at a Home Depot receives the EGO-ECO coupon on a new Smart Cell Twin Pack at a deep discount. EGO-ECO is a win, win, win that rewards customers who recycle unit of proto-tech for the option of purchasing 2 longer lasting units of smarter tech.  
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Blue Angel, Champion

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I like the idea of an Ego trade-in program where you get credit towards a new Ego battery for turning in your used pack that has outlived its useful life.

This, I believe, would need to be done through Ego and only honored for those turning in packs which they had bought new from an Authorized Retailer and registered with Ego. This would be an AWESOME incentive plan to keep loyal customers over the years, something like 50% off replacement packs once your pack is out of warranty.
(Edited)
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(a)Typical Engineer

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This is a great post; last time it saw the light of day was a year ago, so BUMP!

I should add some relevant comments too... I have FOUR 2.0 and 2.5 packs (have a 5.0 in route, but will take a while to cross the Pacific).  So they way I used them in the 20" mower is that I run either 2.0/2.5 for about 15 minutes, then change it out before it goes RED.  And I always let my packs cool back to room temperature before re-charging.  And having read this thread, I'm boxing up the fast charger, and using the slow ones instead!
(Edited)

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