Curious on battery life

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Hello, I was wondering how long the lithium ion battery is expected to last before it needs to be replaced. Also how much do replacement batteries cost. I was looking at the 7.5 amp battery.
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Paul Partington

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Posted 2 years ago

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Oregon Mike, Champion

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This is Ego's stance as of May 1st on battery life - "A battery’s life is measured in terms of recharge cycles, thus it is nearly impossible to predict the number of cycles your battery will produce because of varying environmental conditions. We do have a 3 (three) year warranty on all batteries and chargers, so you can feel confident knowing your battery will be protected in the unlikely event that it doesn’t function properly in those first three years of ownership.". 

Price on HD website is $398.21 for the 7.5 ah battery.
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Egocentric

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The Ego response while correct, is spoken like a true lawyer or MBA.  It is true, but truly vague, and not very satisfying.    

I have no idea how long the average battery will last, but my thought is that Ego warranty is well below the average life.  Kicking around here I have seen estimates of up to 10 years.  That sounds a little optimistic to me.   My guess is that for the average battery and the average user you are looking at 5 to 7 years.  Now what is an average user?  The person who lives in Montreal is going to have a far different average use than a person who lives in Houston if you are talking mowers.     

Anyhow that is my guess, and that is exactly what it is, a guess.  
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Douglas Bass

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I have a 20 inch mower from Ego Power.  I am on my third battery in 5 years.  each one lasted about 18 months and then it would no longer charge.  These were replaced for free as a warranty item, but now the third battery is will not hold a charge an as it has been longer than the 3 years from the original purchase, I fear I will have to dump a couple of hundred dollar for a new battery.
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Jacob

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I have original batteries going on their 6th year with probably close to 500 charges on them. They are still going strong. I have 8 total. I have never had a battery issue. How you got 3 is odd. But I would assume your charger is the culprit.

Also I don't store mine at the recommended storing voltage. Mine are always charged unless they go into storage mode after 30 days if no use. And I am not at all nice to my batteries. I use them on my own built mower.
(Edited)
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szwoopp, Champion

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The odds of getting 3 bad batteries are too high.  As Jacob points out, more likely you have a bad charger or less likely bad tool, or perhaps some bad habit that is killing the batteries. 

A new charger to go with a new battery investment might be cheap insurance.

Perhaps a calm telling of the whole story to Ego CS might get you something.

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Paul Partington

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is there an average number of recharge cycles expected from each battery? did not see that in the manual.
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Egocentric

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Nor have I.  On much lower power densities, I have seen batteries rated at 300 to 500 cycles, which again 500 sounds optimistic to me.  
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Jacob

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I estimate im between 400 and 500 charges on my 4 ah battery.
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BecauseICanTBH

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They use Samsung IMR18650-25R cells according to an official response on these forums, and those are absolute JUNK. You can expect about 100 charge cycles out of them before they're down to 80% of their initial capacity. That's a total embarrassment for a lithium ion battery. They say they're "officially rated to 250 cycles" but if you look at the datasheet, that 250 cycles brings you down to only 60% of their initial capacity. 

Their 56V 7.5AH batteries are about $360. They contain 48 of those 18650 cells. That's under $170 worth of those batteries - and that's consumer pricing. Bulk pricing on them would be $100-130 or even less. I don't know what they were researching and developing for these batteries but obviously not much.
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Blue Angel, Champion

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Care to share the tests that demonstrate the cells dropping to 80% capacity after 100 cycles?

What I see from battery bro is 60% after 250 cycles at the cell’s maximum rating of 20A:

https://batterybro.com/blogs/18650-wh...

Now look at an aggressive Ego application like a small 1P 2.5Ah battery in a blower that discharges in 10 minutes. A fully charged 25R will run at 15A if discharged in 10 minutes, only 75% of its rated discharge rate. So right there we’d expect to see higher than 60% capacity after 250 cycles, quite a bit higher actually since the cells will be operating at a much lower temperature.

Now consider Ego’s phase change cooling sleeves that limit cell temperature during discharge and forced air cooling during charging. This will keep temperatures much lower than open air discharge testing at 15A.

And finally, Outdoor Power Equipment in a consumer application gets used about once a week on average. If we assume the cells keep only about 80% of their capacity after 250 cycles (likely a conservative estimate), then that’s 80% capacity after about 5 years of continuous use.

This is pretty much a worst case scenario using Ego’s smallest battery in a very high drain device running wide open from start to finish. Batteries are typically discharged at 1/3 that rate (30 min) or even less.

So please explain to me how the Samsung 25R is not well suited to this application?
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szwoopp, Champion

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What !?!?  You mean Ego batteries aren't Junk or Trash

Rather many people chose the Ego platform specifically because of their batteries
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Blue Angel, Champion

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As a package, nobody does a power tool battery better than Ego.

It should be noted that the Samsung 25R is a very popular cell in smaller battery power tool platforms as well. Makita, Milwaukee, DeWalt and likely a lot more have all used Samsung’s 25R cell.
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Blue Angel, Champion

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Official Response
Paul, Ego's 2.5, 5 and 7.5Ah batteries use Samsung 25R cells, a highly regarded high-drain cell designed for these applications.

They are officially rated at 250 cycles, but that is at a continuous drain of 20A, their maximum rating.

Even if the 1000W motor in the 21" SP mower was running continuously at full power (it never will), the mower would draw 20A from the battery. Since the 7.5Ah battery has three parallel strings of cells (3P), each string of cells (therefore each cell) will see only 1/3 of that, or about 6.6A.

Depleting the cells at 6.6A instead of the rated 20A will lengthen their cycle life considerably compared to the 250 cycle rating, and that's IF the mower was drawing 100% load at all times, which would never be the case.

Also, Ego's Battery Management System doesn't charge the cells to their full 4.2V 100% charge capacity, nor does it drain them to their minimum 2.5V 0% capacity, both of which also reduce the impact of cycling.

If you figure mowing once a week (50 times per year), you can conclude that for most people the batteries will age faster due to time than cycling.

My personal estimate is 5-10 years depending on conditions, but it could be longer for someone who doesn't need all of it's capacity to get the job done. If the battery is 10 years old and has fallen to 60% of its original capacity, the battery is still good if it has enough juice to get the job done.

Simple answer: It depends. :-)
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Burugee

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Interesting post ; 

Where you find, EGO do not charge battery to 100%. I see people reporting 58.x V after fully charged. Isn't it near 100% ?
(Edited)
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Burugee

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It is estimated on a 7.5Ah battery Mower can run for 1Hr. It is also estimated, same battery is ~360WHr. If you assume average volate during this 1Hr time to be 48V, you can calculate the average drain is 360W / 48V = 7.5A. So each cell average drain should be around 7.5A / 3 (3P  sets in parallel) = 2.5A. This is very close to 1C rating, and shouldn't have issue. (So 7.5Ah or 5Ah packs should not sweat)
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Blue Angel, Champion

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There's a video on YouTube comparing the Echo and Ego batteries, and the Ego is charged to a lower voltage per cell. This is very likely a strategy to increase the cycle life of the cells. It will also help with keeping charge times low.
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joe

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Samsung 25R cells-so it is a chance of explosion due to samsung brand ??
(Edited)
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Jacob

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What.. that's rediculous. Where are you getting this information from?
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Blue Angel, Champion

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Joe, there’s absolutely no relationship between the cylindrical Lithium Ion cells in Ego’s batteries and the faulty Lithium Polymer pouch batteries in the Samsung Galaxy Note 7.

If you want to know what happened with the phones read this article:

https://www.cnet.com/news/samsung-gal...
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BecauseICanTBH

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Samsung 25R cells are trash. You can expect about 100 charge cycles out of them before they're down to 80% of their initial capacity. That's a total embarrassment for a lithium ion battery. They're "officially rated to 250 cycles" (meaning "falsely rated to 250 cycles") but if you look at the datasheet, that 250 cycles brings you down to only 60% of their initial capacity. Cycle life ratings are supposed to be to 80%.
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Ken, Champion

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You’re entitled to your opinion but it would be nice to see you back it up with some evidence. I have a couple of a Ego batteries that I’ve been using for three years that have the same capacity they had when they were new.
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Jacob

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I've got over 500 cycles on my original 4ah batteries.I must have gotten a good batch of those batteries.
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Michael G

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Battery replacement life has to be a big concern for everyone since right now the cost is so high. I see the 7.5A-Hr battery is $400+tax for a $500 mower!?

I ended up getting the mower and more after doing some research. I also thought about my same worries with power tools. I purchased Makita 18V LXT tool set at least 10 years ago and have been good about rotating the batteries and keeping them charged and they all still work today. I have added more Makita tools and batteries as time has passed. Not only has the price of the batteries dropped but I can get double the A-Hr's today from the same size battery. I'm hoping with added competition for EGO the same will happen in this industry.

Mike
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Blue Angel, Champion

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I bought into Makita's LXT line in 2008 and never looked back, they've been terrific tools!
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Jason Harris

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My 5 AH battery failed in just under 3 years, and the 2.5 AH battery is failing at 2 years.  They were used extensively but not abused (never dropped or got wet, etc.).  Both were replaced under warranty, but considering 2/3 of my batteries failed within the warranty period I'm not very optimistic about long-term reliability.  Considering the prohibitive cost of new replacements, I'm hopeful the market will respond in the coming years with options for aftermarket and/or rebuilt batteries.
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William

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My understanding is that lithium ion batteries are the weak area in every application where they are used.  They supposedly have so many charge cycles, but what I read is that a full discharge then charge cycle shortens the life more than two half discharge then charge cycles.  And so on.  LiOn batteries are the worst thing about a Tesla, a Chevy Bolt, other electric-only cars, and their the worst thing in your iPhone.  The good news is for the oil companies.  Lithium Ion is not going to replace fossil fuel.  Not ever.  However, the consensus of what I have read is that the longest life for a lithium ion battery will come from never being fully discharged and topping off whenever possible.  EGO's lithium ion batteries may be different, but I doubt it.

Even Apple has come around to acknowledging the truth.  The company used to recommend a procedure for what they claimed was reconfiguring the battery.  What the procedure actually did was to reset the 100% mark to the current full charge--which might be 98% or it might be 75% or less.  Now at least there is a settings screen labeled "battery health" that tells you the actual current max charge capacity.  My iPhone 7, for example, is at 92% of its original capacity.  It almost never goes below about 80%, as I have it connected to chargers on my desk, in the kitchen, and in my car.  I carry both a charger and spare external battery in my briefcase.
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Jacob

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The biggest thing they will kill your ego batteries are

Shelf life,

Charge discharge cycles, unless your like me, you will only charge them a few hundred times over 7 years.

7 years of life will cause more damage to the battery than your charger. Especially if kept at full charge all the time.
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szwoopp, Champion

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Am I reading this wrong or are you guys giving conflicting info/advice.
William - best = "topping off whenever possible"
Jacob - worst = "Especially if kept at full charge all the time"
?

William - yours seems to be opposite of things I have read and the manuals.  And Ego's 30% long term storage default. 
(Edited)
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Jacob

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Keeping the battery charged full created some issues in the cells. Something about crystals growing and shorting out the battery when charged all the way and sitting.

https://batteryuniversity.com/learn/a...
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dhau001

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Keeping lithium battery at 100% is one of the worst thing you can do, as bad as storing it at high temperatures. Doing both will absolutely destroy a battery. 40-80% range is ideal. Charge up just prior to usage is best. Below 20% is very bad as well. So keep the battery in the sweet spot and that will double the life expectancy.
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martin Downs

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I now have 3 56 volts. Two are one year old and one just got it 4-2020. I see a big difference with the new battery. Last 1/2 hour on my blower. The other two last 15 minutes. I do use turbo button all the time. Am I happy with E-go ? Yes. Very happy. There service is A+. I didn’t expect the batteries to last more then 3 years. I buy $350 batteries for my boat and they only last 2 years.