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 3 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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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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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.
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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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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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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:
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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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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.

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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!