Lifespan of 7.5amp battery and cost to replace?

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I'm considering purchasing an EGO 21" Power+ Self-Propelled mower. At Home Depot price is around $499. How many mowing seasons should I expect to get out of the 7.5 battery pack before it needs to be replaced? What should I expect to pay for a replacement battery?
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Sandy

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Posted 6 months ago

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SCDC, Champion

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Want honesty?  I'm seeing about 3 seasons of heavy use.  I've had to have 2 of mine replaced, luckily both just under 3 years so under warranty.  Others may be having much better luck!!

Pricing seems to be in the low $300's.  So best to just get it in a tool with kit.
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Pete Innes

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Had ours for 2 years and we cut 50 properties per week. So think of the amount of charges we do. We’ve had 1 battery fail but was replaced under warranty. The others are all working like a champ
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TheAtomTwister

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Always good to hear that lawn guys like myself are having good luck with batteries.
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szwoopp, Champion

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I am expecting 10 years from mine
$499 is a great price for that kit
7.5 is currently $358 at HD
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Howard Hoffman

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Life expectancy depends on how well you take care of the battery according to the battery owners manual. The 56 volt 7.5 ah is $359.00 with the 3 year warranty at Home Depot. But eBay sells it for $278.00 without the warranty, the 3 year warranty is $41.00 more. This battery provides the optimum performance for your mower. You can can save buying a lower amp battery, but run times do change. Love the mower when the power increases when you cutting into some high or thick grass, and then decreases when power is not needed. I don’t know if smaller amp battery will still give me this type of performance. But love ❤️ the technology!
(Edited)
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Ken, Champion

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I have a 2.0, 2.5, 4.0 and 5.0 Ah batteries, with the 2 and 4 being three years old and the others being 2 years old. All are used multiple times per week and all are still holding charges like they were new.

I still think the 5.0 Ah battery is Ego's sweet spot. It has excellent runtime and is $220 on its own. The 7.5 is a great battery if you get it with a kit, but if I ever had one die out of warranty I'd replace it with a 5.0.
(Edited)
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Blue Angel, Champion

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I have 2, 2.5, 4 and 5Ah batteries. All are doing very well except my original 4Ah, which started acting up and was replaced under warranty about 2.5 years in. It still works but goes into “overtemp” on the mower and shuts down.

Barring any electronics issues, the cells should be good for 10 years or more for most residential users.
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TheAtomTwister

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One thing I might change with the mower is I would put some kind of air vent in the battery chamber.  It might need an air filter, which is the only downside, but that would help keep the battery cool.  Additionally, I must note that I do not have an EGO mower, but a neighbor that has since moved away had one and I got to work with it a small bit, and I do not remember seeing any vents in the battery chamber.

Also, copied from another post of mine, "a tip for maximizing the battery packs' longevity: when not in use, keep the batteries partially charged.  30-40% charge is ideal for storage, but anything other than keeping them fully charged or fully discharged would help quite a bit."  Batteries being stored fully charged or fully discharged I think is why the thought, "Lithium-ion batteries like to be used" flies around a bit, which is contrary to NiMH and other battery types, so long as you do not heat them up too much.
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TheAtomTwister

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One thing I might change with the mower is I would put some kind of air vent in the battery chamber.  It might need an air filter, which is the only downside, but that would help keep the battery cool.  Additionally, I must note that I do not have an EGO mower, but a neighbor that has since moved away had one and I got to work with it a small bit, and I do not remember seeing any vents in the battery chamber.

Also, copied from another post of mine, "a tip for maximizing the battery packs' longevity: when not in use, keep the batteries partially charged.  30-40% charge is ideal for storage, but anything other than keeping them fully charged or fully discharged would help quite a bit."  Batteries being stored fully charged or fully discharged I think is why the thought, "Lithium-ion batteries like to be used" flies around a bit, which is contrary to NiMH and other battery types, so long as you do not heat them up too much.
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Jack Tyler

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Li-On batteries come in many flavors so an E-bike, iPad and E-lawn mower don't all share the exact same LiOn chemistry.  But in general, 'good care' of a LiOn battery means not drawing it down to zero, leaving it in a semi-charged state (vs. completely full or empty) when stored, insuring warm winter storage if living in a seasonal climate, and not leaving it in the charger once it's fully charged.  Or at least those are suggestions I've received from E-bike manufacturers and Ryobi.  Daniel at Ego might be a good tech support contact to learn more.
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Blue Angel, Champion

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Many of those care items are baked right into the electronics in the Ego batteries, one of their strongest features IMO.
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TheAtomTwister

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I am not sure that the term LiOn is a proper reference to lithium ion, I think that might actually refer to a completely different type of battery, correct me if I'm wrong.

The only thing I would like to see changed is for the storage mode of the EGO batteries to set in with the push of a button (or two buttons at the same time to prevent accidents) instead of a 30 day wait, which is plenty of time for the battery to degrade from being fully charged in storage.
(Edited)
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Blue Angel, Champion

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Offering a manual method of reducing battery degradation would be to admit that the battery system has a weakness. Try getting that through the marketing department.

In this day and age of technologically complicated consumer gadgetry, ignorance is bliss as far as most are concerned. Things need to “just work” without requiring a deeper understanding of how. Only nerds like us know or care about the small technical details that make things tick behind the curtain.

I think Ego has done a very good job at offering the 95% solution. Could it be better? Technically yes, but every layer of “functionality” you and I get is another layer of “complexity” for the average consumer. It’s a slippery slope and product planners generally like to play it safe.
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TheAtomTwister

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"Offering a manual method of reducing battery degradation would be to admit that the battery system has a weakness. Try getting that through the marketing department." 

In my perception, this is not a matter of marketing and does not have to get through the marketing department, it needs to get through to the engineering department.  As the great Mr. Spock said, to deny the facts is illogical.  It is not a critical weakness, but a weakness it is nonetheless.  EGO Always strives to make their products more perfect than they were before.

In my mind, a storage mode is simple enough and simply stating that it maximizes the longevity of the pack in the manual is simple enough, and I'm betting that many other regular guys and gals will think the same thing.  The reasons behind why the batteries last longer in storage mode they do not have to know, but they can if they want to, which means for the most part, that only the nerds like us will know.

Every time I suggest in idea now of days, I always keep in mind not to make interfaces too complex to the point where people will complain about the tools being to difficult to use.  I also keep in mind price point.  Every new component that you add to the units increase their production cost, which will drive up the price, which would defeat what EGO is trying to do.  Yes, their stuff is expensive, but not unaffordably so.  That is one thing we do not want to change.

In the end, I think the benefits just might outweigh the detriments.  Top that off with the idea of adding a new feature to the pack in my mind does not require EGO to say that something is wrong with the old one, the old one is just fine just like the 480 blower was, but the 530 is better.
(Edited)
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Nekoda

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I'm having a hard time finding any evidence of how long the life of these batteries will be. The life of Lithium-Ion batteries are measured in cycles. For example, an iPhone battery will last 1000 cycles before needing to be replaced. One cycle equals 100% of total charge. So, if you charge it 30% one day and 70% another day, that's 1 cycle. I cannot find how many cycles these batteries are supposed to have. I've been trying to contact the company and can't get through.

Does anyone know the answer?
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Bryan

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I don't have the exact answer, but generally you can expect about 400-1000 charge cycles out of a good quality lithium ion battery.  Even if that lifecycle is a low 500 cycles...the end of a battery's "life" doesn't mean that it's dead and unusable but that it can only be charged to 80% capacity.  So in my case where I only use about 60% charge of my 7.5 Ah battery on my lawn... even after 500 cycles the battery will be more than enough.  If you're using this as a normal home owner and take good care of this battery...even at 50 cuts a year the battery should provide you a decades worth of mowing. I'm of course assuming no manufacturing defect and the circuit board on the battery remains in good standing.
(Edited)
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Bryan

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The primary reason I chose EGO was the battery design. There probably is no power tool Lithium-Ion battery and charger better designed to prolong the life of a battery than EGO. Electrek posted a great article on the subject of battery life and the things you should avoid doing with your battery: https://electrek.co/2018/05/04/are-you-killing-your-lithium-batteries/

The top two ways to kill a battery is to charge them on a hot day in the garage and to charge them at 100% with no follow-up use for an extended period of time. As Blue suggests, EGO's chargers prevent you from charging an overheated battery and the batteries will discharge on their own down to 30% after 30 days of no use.  For myself, though I'm not going to hesitate to bring the batteries into the house when extreme temperatures are found in my garage. Also, I used to charge the battery right after use but reading the article I've decided maybe it's best to recharge Li-ion before use (as long as the batteries aren't completely discharged).
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Blue Angel, Champion

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Great summary Bryan!

Anyone interested can look up the discharge performance of the Samsung 25R cell. That’s what Ego uses in their 2.5, 5 and 7.5Ah batteries.
(Edited)
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Jack Tyler

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Bryan, thanks for sharing the article link. Good stuff! And the range of life cycles offered in the article is similar to other articles I’ve read except perhaps overly generous on the high end. However, here are a couple of “adds”: Altho’ not mentioned , another very harmful behavior is to draw a LiIon battery down completely. So e.g. if you know that mowing both front and back yards will fully deplete the battery (motor simply stops) and a partial recharge is needed to finish the job, then mowing one yard followed by a charging period and then the second yard is better battery management. And as we generally are moving in the direction of accumulating more and more LiIon powered tools, toys and gadgets, maybe it’s time to start thinking in terms of designating a permanent, convenient and moderate-temp storage and charging location for all batteries. I know in my seasonal climate (Montana), this really is required for better life cycle performance.

Good thread!
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Bryan

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Yes, and that's where I'm a little unclear in my knowing. Once the battery light is blinking red indicating that the battery pack is nearly depleted...just how close to depleted is it? The circuitry on the on the battery will shut off the tool to protect the battery pack from over discharging. I suspect the circuity shutdowns the battery at a low voltage of 5% or 10% (hopefully it's 10%). Either way, as you mentioned, it's not worth the health of the battery to see how far you can push the battery once that light goes from green to red.
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szwoopp, Champion

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per the manual - the mower will show green until the battery is below 15%.  Then it will show red.  The manual advises you to stop mowing and change the battery.

If you get to blinking red, the battery is nearly depleted. No % given.

So I would say it is the best practice to change the battery as soon as the mower displays a solid red.
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SCDC, Champion

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I'm enjoying this thread, but it just doesn't account for having 2 7.5Ahbatteries die within 3 years and so few charging cycles.  Probably luck of the draw, I am lucky in that sort of way.  I am down to 2 7.5Ah batteries, which allows me to just about get my lawn work done.  I miss my 3rd!   I follow up with my 5ah and 4ah batteries which are going on 4 years old and show very little run time differences from years ago.  Very happy with those!!
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Nekoda

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Those are good points that everyone has contributed. I work in technology so I understand all of the ins and outs of Li-ion batteries but my question has still not been answered by anyone and this is sort of my point. I’m nervous to buy from a company who refuses to make their expensive battery life cycle number customer facing and when I try to get in touch with their customer service its like I’m playing chicken with the automated on-hold voiceover. I can’t imagine what I’d do if I bought their product and actually needed help! A lot of people have estimations but I’m looking for a factual number, not a guess.

I’ve been reading more stories about how people are oddly going through these batteries very quickly, like within a year or two. They are very expensive to just hope I get “decades” of use as one assumed in a reply. Also, the batteries have a 3 year warranty but people who are burning through them within a year aren’t getting them replaced under warranty which means either they didn’t think to ask or the company considered them consumed. I downloaded their battery manual and read the entire thing. There is nothing in there about the number of cycles in the life of their batteries. It makes me really nervous.
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SCDC, Champion

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I wouldn't be so nervous.  Mine died, 1 in warranty and got it replaced, and one out of warranty, trash.  I don't think charge cycles should even matter for a consumer lawn tool, because who charge 100 cycles a year??  I may see 20-30.  So, it wasn't charge cycles that got mine, I have no idea what did.

I really don't think there is a better quality battery pack on the market (all of the safeguards against heat, etc). 

Remember, that you mainly read complaints online, people who don't have problems, generally don't bother with forums.  So even with my data of problem batteries, the over all picture is probably pretty skewed towards problems, when it isn't as bad as it seems.
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Jack Tyler

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Nekoda, I'm sympathetic to your point.  And e.g. you'll find this same kind of variability i battery performance among the ebike community, so it isn't just EGO.  OTOH if you work in tech you'll be familiar with the interface between design, manufacturability and QA on the one side and a varied customer base on the other.  Simply lots of variables.  The one thing large conventional battery manufactures do, to address just your question, is set up a standardized testing regimen and then publish the results.  This shows how many cycles to half-life (50% of original capacity) when drawn down X amps at Y voltage for Z time.  We used this data e.g. when picking house batteries for a cruising sailboat.  BUT...that only suggests POTENTIAL battery performance and doesn't account for all the above variables nor does it reflect the type of use a given customer makes of the battery.

Also, since you read the manual, you know that EGO recommends a maximum period of dormancy before some charging should be done.  So one wonders just how long some of these batteries have been in the shipping/distribution/retail store cycle.

What we may all be realizing is that, at least given current technology, choosing a energy dense battery includes accepting some potential variance from the promised performance.  Even if we wish it weren't so.

Jack
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Michael G

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I've had many Makita LXT 18V Li-Ion powered tool for over 10 years and only charged batteries as required, I just had my first battery that would not take a charge about a week ago.

This experience gave me confidence in the growth of battery technology enough to replace all of my aged gas lawn tools over the past two seasons. I have between $1500-$2000 invested in EGO.

I love the tools! Quiet, powerful, unique, lack of maintenance...

What is worrying the heck out of me is the "infant mortality" of the EGO batteries. Last year I had a battery start blinking green. I see several others had the same issue. Called CS and they sent out a replacement. Was confidently told this was a battery batch issue. Felt OK until last week when the replacement battery bit the dust with the same green blinking light.

Three year warranty seemed reasonable when I bought the tools since my previous Li-Ion experience was great, but, now I only have this season and next left for battery warranty. So these design related failures really have me nervous since battery replacement costs are astronomically high and like others did cost justification based on at least 5-year battery life.

Mike