Ego 7.5AH Battery capacity over time (Battery Degradation over time) – 4 year update

I own three 7.5AH Ego batteries. My earliest had a manufacture date of 2014 (although I purchased it in 2017 with a mower manufactured in 2016). I now have four years of operation on this battery.

As shown in the graph, the capacity dropped off over time (down to a low of 260 watt hours in year 3, which is 63% of the original 410 watt hour capacity), but in year 4 it has actually increased a bit to 290 watt hours (70% of the original capacity).

My 2nd 7.5AH battery was purchased in July of 2018 (manufactured in May of 2018).

As you can see, its graph has gone down, and so far hasn’t popped back up.   At the three year mark it is also down to a 260 watt hour capacity (63% of it’s new capacity).

My third 7.5AH battery has a 2019 manufacture date, but it’s still in its first year of “use”, so I don’t have a fancy graph for it yet, although I have started to include it in the comparison bar graph below:

So far, all three of my 7.5 AH batteries have followed a very similar capacity vs time curve, and you can expect one of these batteries to retain an average of 90% capacity in year 1, 72-75% capacity in year 2, and 63% capacity in year 3.

[Plus, they MAY bounce back up to 70% capacity in year 4, if the other two follow the path taken by my first battery.]

Right Wheel Locking on Ego 21″ Self Propel unit

My 21 inch Ego mower with the updated self propel unit has developed an annoying quirk. Some of the time when I try to move it, or make a turn at the end of a row, the right wheel “locks”. This isn’t an issue when making right pivoting turns, but when you are trying to pivot around the left wheel and the right wheel locks up, it stops the turn.

It appears to happen both with or without the mower motor engaged. It sort of acts like the “anti-roll-back” feature, except that I’m not trying to make the mower go backwards, and it’s always the right wheel that locks up, never the left.

I had never noticed this behavior before a month ago, so it appears to be a newly developed issue. So far the self propel unit is working fine when engaged, but given my history of self propel unit failures, I’m concerned that this quirk may indicate something in the motor control unit is having issues…

June 2021 Update:

The issue shown in the above video kept getting worse until I called Ego support and described it to them. They immediately sent me to the local Ego certified repair place who fixed the issue in about a week. The issue was that the nylon gears at both ends of the drive shaft (as well as the plastic gears inside the wheels) were worn down and slipping/jamming. The shop tech said that he replaced both the motor/drive unit and both wheels. Here is a photo comparing what the nylon gears are supposed to look like with what the actually looked like.

Ego 21″ mower (LM2100SP) 3rd self propel motor failure & repair report

My Ego 21″ self propelled electric lawnmower started on its third self propel unit failure back in June of 2019.   For those keeping track, I bought the Ego 21″ mower back in April 2017, and it’s self propel unit failed in October of 2017 I took it to Home Depot to be repaired (which took 6 weeks) and the repaired self propel unit lasted until July of 2018. Ego customer support was nice enough to send out a replacement mower that time, so my downtime was only 10-15 days, and I was hopeful that the replacement mower might have a better self propel unit in it. Unfortunately, that one started to fail in June of 2019, so it looks like the lifespan of my self propel units are 4 months, 10 months and 11-16 months.

So, back in June 2019, the self propel unit just stopped working much like it had previously. I called Ego customer support and they offered to ship me a replacement mower. We had that all set up, but the next day I went out to push-mow the rest of my lawn, and lo-and-behold, the self propel unit had “reset” and was working again! So I called Ego back and canceled the replacement.     Unfortunately, although the self propel unit had not totally failed, it had not fully recovered, and still had some issues that got gradually worse over time. Specifically, the top speed was reduced, and over the next several months, the power and top speed appeared to keep dropping. Eventually it got to a point where it would not propel the mower up a slight hill without me assisting. Eventually, in January of 2020, the self propel unit failed completely, and did not “reset” itself.

Ego shipped me a replacement mower and I shipped the bad mower (my 2nd) to them, so I am now on my 3rd Ego mower (and year 3 of my 5 year warranty). However, for the first time in 3 self-propel failures the SP unit is different! The new mower (manufacture date October 2019) has a different style of self propel unit when compared to the three units that had failed on it in the past. The old unit had a gearbox on the drive shaft and the motor body stuck upwards at a 90 degree angle. The new unit has the motor body above but parallel (horizontal) to the drive shaft. I don’t know if the old unit had a fan, but the new unit has a fan clearly visible.

Older Self Propel Unit


New Self Propel Unit

Objectively, the new self propel drive unit doesn’t look as impressive as the older unit, but given the number of failures I have had with the old style, I’m excited to have something change (and hopefully improve). From a performance standpoint, the new self propel unit works just as well as the old style, so there is no loss in performance. I just hope that it will have more longevity than the older units.

I suspect that the size of my yard (which is large enough that it takes me two 7.5 AH batteries to mow it in the fall/winter, and up to four 7.5 AH battery charges in the heat of summer) may be the reason the self propel unit’s are failing. I suspect I’m putting a lot more “miles” on the SP unit than most Ego owners, plus they seem to be failing in the heat of the summer. I’m not sure if that is due to heat related problems, or if it’s due to the grass growing more in the summer.

Ego Battery degradation over time (2 year mark)

I’ve been tracking how much power it takes to charge my Ego batteries since I purchased them. I’m using this as a stand in for how much capacity they retain over time. You should know that I have a large lawn (in Florida) and cycle these batteries at least once a week (more in the summer) so these batteries are getting more of a workout than if you had a small city lot that you could mow a few times before charging the battery.

I have two 7.5 AH batteries (one bought before the other). They took 410 watt hours to recharge when new. After one year of usage, the remaining capacity was (78% 320 w/h and 82% 340 w/h) on the two batteries. My older battery has two years of use, and has 70% of it’s original capacity (290 w/h).   So it looks like they drop between 18 and 22% of their capacity the first year, and an additional 8% the 2nd year for a total loss of 30% of their capacity after the 2nd year of usage. [The batteries have a 3 year warranty.]

30% capacity loss in 2 years

Update: See my new post at the 3 year mark for the 2014 battery (and 2 year mark for the 2018 battery).

Ego 21″³ mower (LM2100SP) 2nd self propel motor failure & repair report

No, this post isn’t an accidental duplicate of this post from last year. Yes, the self propel unit on my 21″ SP Ego lawn mower failed a second time. (This is 9 months after it was replaced under warranty from the first failure, which occurred around month 4 of ownership, so this failed self propel motor lasted twice as long as the first one.)

However,   I’m quite pleased with Ego’s warranty service compared to the last time when I had to take the mower to Home Depot’s service department (who kept it for 5 weeks).

This time when I called Ego’s customer support number, I only had a seven minute hold time before talking to a person, and the customer support representative said that they would send me out a new replacement mower, arriving in 5-10 business days. [I was instructed to remove the serial number sticker and take the defective mower back to home depot “for recycling”.]

I have read many accounts on Ego’s customer web forums of other self propel units failing, so they may have had a bad batch of mowers go out and are now being more pro-active about replacing them. Alternatively, maybe I’m getting a replacement mower shipped out quickly because this is the second issue I’ve had. Regardless, receiving a working replacement in 5-10 days is much better than taking 5 weeks for a repair.     I’m still going to have to push my mower to mow the lawn (and it’s a big lawn, so this is more exercise than I am looking for….) but at least I could use the defective mower as a push mower until the replacement arrived and didn’t have to hire a lawn service while it’s in the shop.

The new mower arrived 11 business days after my phone call (it would have been 10, except UPS had a delivery exception and delayed it over a weekend, which meant I had to push the old mower around one more time.

After using the new mower with its super quiet and silky smooth self propel, I can say that the self propel unit that home depot repaired/replaced had many signs of problems before it finally gave up the ghost. First, it was louder than the mower itself. Second, it didn’t have enough power to fully propel the mower up a slight incline. Third, every time the mower went into overdrive due to thick grass, the self propel would slow down. These issues were either there from the time I got the mower back from Home Depot, or they started and got worse so gradually that I hadn’t taken note of them, but after using the new mower, it became obvious that I should have known my self propel unit was not working the way it was supposed to. On the new mower the self propel has plenty of power to move up a grade at the same speed it moves on flat ground, it makes less noise than the blade mower, and it doesn’t slow down when the blade mower goes into “overdrive” cutting thick grass.


Update: Ego has started to produce updated 21″ SP models that have an updated self propel unit that matches that found in their dual battery (premium) mowers. Look for a picture of a phone on the box (see this video for details: )

2nd Update: My self propel unit failed a 3rd time, but this time Ego replaced the mower with one that has a different looking SP unit, so I’m hopefully I got the improved version!

Degregation of EGO 7.5 AH lawnmower batteries over time

I purchased a 21″ Self Propelled EGO lawnmower in April of 2017, and although the mower’s manufacture date code was listed as Sep 2016, the 7.5 AH battery (Original Battery) that HD gave me (shipped separately and lost for a week) had a date code of Dec 2014.

I just (July 2018) purchased a second brand new 7.5 AH battery that has a manufactured date code of May 2018 so that I can mow twice as long, and be charging one battery while mowing with the other.

To monitor the performance and lifespan of these (relatively expensive) batteries, I have been periodically testing their capacity by draining them to the same level (when the red light on the mower comes on) and then measuring how many watt/hrs it takes to fully recharge them using a Kill-a-watt meter. In this way, I can compare the original battery (both last year and now) to my new battery.

Here is my data:
Original Battery Aug 2017:   380 watt/hr to recharge
Original Battery July 2018:   330 watt/hr to recharge
New Battery, July 2018: 410 watt/hr to recharge.

I didn’t start keeping track of how much power it took to recharge the original battery until August of 2017, so I don’t know if it was at the 410 level when I originally received it or not. It’s calendar age from the date of manufacture was 2+ years old when I received it in April of 2017, and I estimate it probably lost 7% of its capacity before I started the measurements.

The original battery has lost approximately 13% of it’s capacity over the last year from the point I started keeping track.
(380-330= 50 / 380 = 0.1315 )

Right now, my brand new battery is 19-20% “better” than my original battery (which is 3+ years old and has been in active use for 15 months).
(410 – 330 = 80 / 410 = 0.1951)

Said another way, my original battery still has 80% of the capacity of a “new” battery after 15 months of use and several years of storage before I purchased it.   (330 / 410 = 0.8048 )

Just for fun, here are two graphs of the data points I have for my original battery over time. The first one shows how the degradation appears to be mostly linear (at least over the last year) but looks scary, because OpenOffice cheated and auto-scaled the vertical axis to only include the data points.


This second graph represents the total capacity “under the line” is a better visual representation of reality, as only 13% of the original capacity was lost over this time period (20% when compared to a brand new battery, so the other 7% was likely lost in the years of storage before I received the original battery).


Update: See my next post for two years of usage data on my original battery, and 1 year on the new battery.



Ego 21″ Self Propelled 56 volt Power plus lawnmower review

In April of 2017 I purchased an Ego 21″ Self-propelled electric lawnmower (Model LM2100SP), and I have been somewhat happy with it despite two failures of the self propel drive unit that were both repaired/replaced under warranty.

I still believe that an EGO mower is the best option if you are going to be buying a cordless electric mower, but there are a lot of caveats you should know about if you are trying to decide between it and a traditional gas model.

Performance and “Range”:
The Ego has comparable performance (cutting power) to a gas mower (and an impressive ability to automatically ramp up the torque if needed), but it can’t compete on range with the energy density of gasoline. My mower came with the largest 7.5 Amp Hour (AH) battery, and I need to re-charge it once (winter) or twice (summer) to mow my 3/5 acre yard in two or three sections. I can usually mow for between 30-60 minutes at a charge depending upon conditions (cutting thick wet grass with a dull blade takes a lot more energy than cutting thin dry grass with a sharp blade).

As an example, I was able to mow this section of my lawn (from the foreground to just past the pine tree to the right of center) on a single charge (until the status light on the mower turned from green to red, leaving just enough power in the battery to use it in the leafblower to clean off the lawnmower and a short sidewalk). The section was 66′ long by 130′ wide, (8,500 sq ft, or just under 1/5 – 0.195 acres ). This was grass that needed mowing (mowed last about 9 days ago) but wasn’t quite overgrown yet. Time wise, this took me around 45 minutes running with the self propel set to maximum speed. As another data point, in the middle of summer, mowing thick overgrown grass, I was able to mow a 5,200 sq ft section ( 130′ x 40′) on a single charge of a new 7.5 AH battery.

With a gas mower you could mow my entire lawn with thick wet grass and a very dull blade and only notice that you needed to re-fill the gas can slightly more frequently. With an electric mower, you learn to keep your blade sharp, and to never mow wet grass (which is good for the lawnmower and your lawn) because it makes a significant difference in your mowers “range”.

My lawn is large, and most homeowners would probably buy a riding mower with a wide deck to mow it, so I don’t mind getting a break between each section. [Electric riding mowers were prohibitively expensive when I purchased my walk-behind Ego.] Recharging the battery takes an hour with the included fast charger, so I can mow one section, recharge while taking a lunch break and then knock out a second section. Usually though, I just mow 1/3 of it each day, so the battery charging speed doesn’t really matter. If you wanted to be able to mow almost continuously, you should buy two batteries so that one can be charging while you are using the other.

The mower will cost more up-front than a comparable gas mower, due to the cost of the rechargeable battery (The battery and charger is warranted for 3 years, while the mower itself has a 5 year warranty). If the battery lasts a full 5 years, your total cost of ownership will probably be very similar to a gas mower + fuel and maintenance. However, if you were to purchase a used gas mower, you can save a significant amount of money. Purchasing a used electric mower was not yet a viable option for my lawn, as most used electric mowers on the market still make use of lead acid batteries and do not have the comparable performance to the Ego’s 56 volt lithium battery pack. If you have a very small yard (1/10th acre or less), an older used electric mower may still work for you.

Benefits of electrification

Once you accept that the energy density of a LiIon battery is significantly lower than gas, there are many benefits to an electric mower. First, it costs me about 5 cents to fully charge the battery (15 cents to mow my entire lawn), and I never have to travel to a gas station to purchase fuel. I will have to purchase a new battery at some point in the future. Currently, it is unclear exactly how quickly the battery will degrade over time. I have detected no degradation after the first four months. It is warranted for 3 years, and I hope it will actually last 5-10 years before I need a new one, but only time will tell. New batteries are expensive, but if technology improves and costs reduce over the next five years, I may just buy an electric riding mower once my Ego walk behind is 5 years old and the warranty expires.

Because the mower has no gas or oil, you can turn it to change the blade or fold the handle and stand it upright for storage without worrying about leaks or damage. This is a prime space saving benefit that I feel is one of the main benefits.

Because the motor is electric, starting and stopping the mower is as easy as pushing the start button and pulling the bail bar in.   No more pull starts, or dealing with a dead starter battery on an electric start model.

The mower is MUCH quieter than most gas mowers. Although it makes noise, it is much less disruptive than even a four stroke engine with a good muffler. And of course, you never have to walk through fumes or smoke from an internal combustion engine.

It also comes with headlights. This may sound like a gimmicky feature, but since the electric motor is so quiet, you can mow later in the evening without worrying about annoying your neighbors. Because the headlights are down low shining across your lawn, they do a very good job of highlighting the mowed/not-yet mowed division, making it even easier to overlap your tracks slightly than in the daytime.

Common Gripes

Reading the Ego community forums (after purchasing the mower) I found several common complaints.   First, it can leave   tufts of uncut grass near the edge of the mower, which can mostly be rectified by overlapping your passes a bit extra. So instead of a 21″ deck, you are really getting the performance of a 19-20″ deck. This may be related to the second common complaint, a lack of suction. Some people complain that it doesn’t always lift leaves or grass upwards enough to cut/mulch. Many of these complaints are from people who bag their clippings and want absolutely everything off of the lawn when they are finished. I use it almost exclusively in the mulching configuration, and am happy with it’s mulching performance. Ego does sell a “high-lift” blade that has more “uplift” specifically designed for bagging operation, which does improve the suction, but at the expense of extra energy usage (shorter runtime). I have the high lift blade and can confirm it does a good job increasing “pickup” when bagging, but I was happy enough with the mulching performance with the standard blade that I don’t use the high-lift blade and bag frequently.

Hardware failures

The third, and most concerning complaint I see on the community forums is failures of the hardware, combined with difficulty contacting customer support and a poor dealer network for repairs (of the mower). I have seen many posts by people who have had motor failures, battery failures, and charger failures. Without knowing how many units have been sold overall, I can’t estimate a failure rate, but they are happening often enough to show up in the community forums as a seriously sour note.   [It doesn’t help that EGO, and their system of Home Depot authorized repair centers some issues, keep reading.]

Repair Difficulties

To be clear, EGO stands behind their products and will replace batteries and chargers if they fail by sending out a new unit. However, their call center is very busy, and hold times of over an hour are reported frequently (and bitterly). The best advice seems to be to call early in the morning to reach a real person, and to never expect them to return a voice-mail. I have talked with two different customer support representatives (to register my mower, and to initiate a warranty repair on the self propel motor) and they were always very helpful (once you got through to them.)

If your battery or charger goes out under warranty, they will ship you a new one relatively quickly. However, if a piece of equipment needs repair, instead of outright replacement, you must take it to an authorized repair center. For most people, this will be the closest Home Depot that has a tool rental / repair center. [If you are lucky enough to have a local lawnmower dealer that is an authorized repair site for Ego anywhere near you, DRIVE YOUR MOWER TO THEM INSTEAD.] Unfortunately, the time to repair a piece of equipment at the home depot repair center is 3-4 weeks if they can do the repair in the store, and 6-10 weeks if they have to ship it to the repair depot in Atlanta.   Think about that, two months without your lawn mower!   (You can read about my repair experience at this other post…)

Update:   The self propel unit failed on my mower a second time after 9 more months of ownership, but I was much happier with how Ego handled the failure, as they shipped me a replacement mower so that I was quickly back in business. You can read about the 2nd failure and replacement at this post.

2nd update: The self propel unit stopped working on my replacement mower after about 11 more months of ownership, and Ego again offered to ship me a replacement mower so that I’ll be back to mowing in only 10-15 days.   However, when I went back out to push-mow the rest of my lawn, the self propel unit was again working (I assume it was some type of self resetting thermal fuse or circuit breaker) and the self propel unit was working again! (So I had to call Ego back and cancel the replacement shipment.)

So far I’m happy with Ego’s 5 year tool warranty (they only offer 3 years on the batteries/chargers), but there are some very important restrictions you must know about.

Important Warranty Restrictions

This isn’t a craftsman hand tool where you can buy a broken one at a garage sale and get it replaced. For warranty service, you need to be the original owner, have proof of purchase (if you have not already registered the product), and you MUST have bought the product new, from an Ego certified dealer (Mostly Home Depot, although they do sell on Amazon as well as through some local lawnmower shops.) Note that if you buy an EGO product on Amazon, you MUST make sure that it is “Sold by and shipped from Amazon” to be covered by Ego’s warranty. Many other sellers will sell via the Amazon Marketplace, but they are not Ego authorized dealers, only products purchased directly from Amazon itself are covered by the warranty.


Ego 21″ mower (LM2100SP) self propel motor failure & repair report

After four months of ownership, around 40 hours of usage, the self propel motor unit on my Ego 21″ Self-propelled electric lawnmower (Model LM2100SP) failed. Before this failure I was very happy with its performance, and although it was repaired under warranty, the procedure took longer than I think was reasonable.

Ever since I purchased the mower, I have been monitoring the Ego community forums, and I knew that reaching a customer support representative would sometimes take extended hold times, and I had heard that taking a mower to Home Depot for repair could be an extended procedure, so when my self propel motor failed, I was relatively well prepared on how to handle the situation.

August 29th, 2017 – The self propel motor fails. I finish mowing my front lawn pushing the mower by hand (which makes me realize that paying extra for the model with the self propel motor was the right choice.)

August 30th, 2017 Time to call customer support. After re-charging the battery, and letting the mower sit overnight to cool, I tested it again (yep, still no motion) and then called Ego customer support early in the morning (to avoid a long wait on hold.). I only had to wait a few minutes on hold, and then a helpful customer support representative walked me through a few simple questions (yes, my mower blade would turn on and spin, so the battery was good, and the folding handle interlocks were correctly latched, etc…) to verify that the drive motor had actually failed.   After that, she “made a note in my file” and told me to take it to Home Depot.

What I wish she had told me: 1. Home depot will charge you a $20 deposit, just to look at the mower (and you authorize up to $150 worth of repairs upon drop-off). They will refund this deposit to you if the work is covered under warranty (mine was).   2. You can only take the mower to a Home Depot that has a tool rental / repair clinic (call first to check). 3. The Home Depot repair clinic doesn’t have their own EGO batteries for testing, so be sure to leave your battery in the mower. [This makes sense in hindsight, but I was hesitant to leave 7.5 AH battery that costs $400 to replace at HD, so this required me to make a second trip back to HD with the battery a few days later.]

Also, after talking with her I received an email from Ego that stated my “case had been closed” (this is the case associated with the phone call to Ego only…but the wording of the message didn’t inspire confidence.)

Because I had heard horror stories about the Home Depot repair clinic taking a long time to repair EGO mowers, I made sure I called them every week to check on the status of my mower, just to make sure it hadn’t fallen into any cracks. I also posted an update every Monday on the ego customer forums, which may have also helped things behind the scenes.

Sep 18th 2017: They are still checking on the mower, but the HD technician felt that they could repair it locally instead of shipping the mower to Atlanta.

Sep 25th 2017: In progress, waiting on a part which usually takes a week or two (presumably the motor/gearbox unit).

October 2nd 2017: HD is still waiting on the part.   [After this update to the Ego community forum, April from EGO said that they were tracking the shipment and that the part should be arriving at the HD store within a few days.]

October 9th 2017: HD claims to still be waiting on the part.   [I mentioned this on the Ego community forum.]

Finally, on Thursday night (Oct 11th), Home Depot calls me to tell me the mower is ready for pickup. Because the home depot with the repair clinic   is 12 miles away from me, I delay pickup until Saturday.

So, it took Home Depot / Ego about five weeks to get my mower repaired, and this was with me keeping on top of Home Depot and making sure that Ego knew what was happening at each step. Reading several other reports on the ego community forum makes me believe that my experience was actually on the faster side of things, as 8-10 week delays are not unheard of if the mower gets shipped to Atlanta for repairs.   I paid $180 to a lawncare company and took a break from mowing my yard, but there are at least three other options to keep mowing if you find yourself in this situation.

Take advantage of Home Depot’s 90 day return policy

Many others in the Ego forums have bought another Ego lawnmower and used it while theirs was in for repair, returning it under HD’s 90 day return policy once their mower was repaired. I felt that this action would be ethically questionable, but after waiting five weeks for HD to repair my mower, my ethical resolve is beginning to weaken, and should the mower fail again, I will seriously consider this option.

Buy a second mower

I did consider buying a second Ego mower (and keeping it), mostly as a way to purchase a second 7.5 Ah battery (it is almost as cheap to buy the battery and mower together as to buy just the battery, plus you get a “hot spare” mower). Other than the fact that you have to store the 2nd mower, this does have certain advantages. If one mower fails, you can just switch over to using the second mower while the first is in for repair. And, you get the advantage of having twice as many batteries and chargers.   Unfortunately,   at the time Home Depot was not offering the same $50 discount on the mower as when I initially purchased mine, otherwise I may have done this.   [My wife points out the questionable logic of using the failure of a product to justify the purchase of a duplicate of the same product…]

Burn hydrocarbons

Of course, you could also buy a cheap used gas mower and several gallons of gas for less than the $180 that I paid for lawn care service, and probably be able to resell it at almost the same price you paid when finished.

Final Recommendation

Due to the fact that my self propel motor failed after 4 months of ownership, combined with a 5 week repair time, I can’t recommend the EGO electric mower to everyone. At least with a gas mower your options for repair are numerous and much faster. However, if you have decided that you will be going with an electric mower, I still think that the Ego line has the best performance. (I have also posted a review of the mower.) I also own the hand-held leaf blower and chainsaw from their Power+ line, and have been quite happy with them.

The new self propel unit installed by Home Depot   failed again (after 9 more months of usage) but I’m much happier with how Ego handled the warranty repair (via a direct replacement), which you can read about here.

2nd Update: Ego has started to produce updated 21″ SP models that have a new self propel unit that matches the one found in their dual battery (premium) mowers. Look for a picture of a phone on the box (see this video for details: )

3rd Update: My self propel unit failed a 3rd time, but this time the replacement I got looks different, so I think I may have the new model now!