Isn't the battery supposed to self discharge to 30% after a month?

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I bought an Ego mower and trimmer last year and after the mowing season brought the batteries inside and put them in a closet. They've been there about 6 months.

From my understanding after about a month they should discharge themselves to 30%. I just took the batteries out of storage and put them in the chargers and they appear to have a lot more than 30% charge. The big battery progressed from 1 flashing light to 4 flashing lights in about 7 minutes and except for the first 30 seconds the fan was on low speed. It's not finished yet, but it looks like it should take less than 15 minutes to finish.

Does it really take that short to go from 30% to full charge or was the battery not at 30%. If it wasn't at 30%, why not?

Edit: so it's taking a lot longer than 15 minutes to charge. It's been about 30 minutes already so I'm guessing the charging percent lights are just wrong.

Edit: so the big battery charged in about 40 minutes. The little one took 5 minutes which makes no sense. That should have also been at 30%.
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Morac

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Posted 2 years ago

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SueLW

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I've never heard that they're supposed to discharge on their own. Mine never has. I recharge them after each use and they're charge up and ready to go the next time I mow, which is usually every 7 to 10 days, I believe if you store them for long periods, it's recommend to only charge them to 30%
(Edited)
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Morac

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According to the official response the battery should drain itself down to 30%.

https://community.egopowerplus.com/eg...
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Blue Angel, Champion

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Official Response
Yes, after 30 days they self-discharge to 30% capacity for long term storage.

Morac, the behavior of your one battery sounds OK.  What size batteries do you have?  The other battery may not be behaving properly, however the 2Ah battery charges in 25 minutes or less from completely depleted.

If indeed the battery is NOT discharging after 30 days you should call Customer Service for a replacement.  To verify this you'll need to leave it sitting for at least 40 days though, as it will take a while to discharge once the 30 day mark passes.  Any use of the battery, plugging it into either a tool or a charger, will reset that 30 day clock.  I'm not sure but pressing the power indicator may even do it; that's just my own suspicion.
(Edited)
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Morac

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I have two. The 5 Ah charged in about 35 to 40 minutes. The 2.5 Ah charged in about 5 to 10 minutes. Both had not been charged for at least 5 months.
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Blue Angel, Champion

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Sounds like your 2.5 might have an issue. As long as it's working well otherwise you can be aware of it for next season and record what's going on with some greater detail. If the battery charges that quick again I'd say to get it replaced. The batteries have a 3 year warranty.
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(a)Typical Engineer

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Without a scientific and repeatable way to quantify how much charge is left in the battery, we're just aimlessly speculating.  About the only way to non-intrusively measure the battery is the terminal voltage at the battery.

That is until Ego introduces a standard power bar meter like everyone else has.
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(a)Typical Engineer

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Or use a Watt Meter connected to the charger, and you can measure how much power is required to "top it off".   I think I'm going to start keeping a recharge log of my batteries; if you graph that data over time you should be able to see the health of your battery.
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Blue Angel, Champion

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I do the same, keep a piece of painters tape on the end of the battery with the kWh it took to charge it from depleted last time. I check them once a year or so.
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(a)Typical Engineer

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Here is a work around way to determine if you battery has entered maintenance discharge mode.  Measure the voltage across the +/-  terminal of the battery pack.

I had four 1P (2x 2.0 AH, 2x 2.5 AH), and had charged them all up to full capcity, and after about a month, they had all self discharged to a measured voltage of: 51.6V, which according to the meter I have is approximately 41%.  Maximum voltage for a 14-cell pack at 4.2V per cell is 58.8V (14 x 4.2).  So if you're closer to 51.6V, your self discharge is working, or if you're still closer to 58.8 volts, then you pack's self discharge may not be working.

More details in this thread:
https://community.egopowerplus.com/ego/topics/how-to-add-a-digital-volt-meter-to-the-charger
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Burugee

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During this self discharge cycle, does the battery gets heated up. (I assume battery has to disipate its charge as heat). Does the light on the back show any sign, like, blinking or some sign to show that battery is discharging?
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Blue Angel, Champion

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There is no indication from the battery other than the end cap getting warm to the touch.
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(a)Typical Engineer

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Not quite true, per the battery manual:

PROBLEM
The battery end cap gets warm during storage. Power indicator flashes green every two seconds.

CAUSE
The battery pack is automatically performed [sic] self-maintenance to extend battery life.

SOLUTION
No action is required; this is normal. Press the power indicator the self-maintenance process will stop.
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Blue Angel, Champion

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I didn’t notice any green flashing lights during the discharging process on my 2Ah batteries, only a warm end cap.

The manual mentions this feature twice, but nothing about a blinking green light.

Page 12:


Page 14:


Where are you seeing mention of the flashing green? I mentioned this warm end cap condition to Ego a couple years ago and suggested they mention it in the manual to ease concerns. Nothing has been added to the manual yet, to my knowledge:

https://cdn.shopify.com/s/files/1/026...
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Blue Angel, Champion

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Interesting... from the European manual:
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Blue Angel, Champion

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My batteries weren’t flashing while discharging, which was concerning since the end cap was warm to the touch. Only when I realized two batteries were warm did I figure out what was going on.

Maybe the green flashing light is a good way to reassure people nothing’s wrong when they grab a hot battery pack? Seems like a good idea to me.
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(a)Typical Engineer

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When I  typed up my response below, I realized that the US batteries do NOT flash the LED when in self discharge mode.  The pack was off the charger as well, so no additional indication of discharge.  I might store a pack on a charger to see if it flashes the green charger LED like the manual says it will.

But I might not be patient enough to watch paint dry for 30 days... =)
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Morac

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There is no light on the back. There's only the one on the button which doesn't do anything other than turn green when pressed.
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John

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I have a similar issue. I've got a 2.5 Ah battery that I put in storage for 6 months at full charge. When I was ready to use it this spring, it was still at full charge. I know that because I put in on the rapid charger, and all four green lights came on, and it wouldn't charge any further. Furthermore, I was able to use it a lot on the string trimmer, indicating that it had way more than a 30% charge. I had expected it to be at 30% charge because on p. 12 of the battery owner's manual it says, "The battery is equipped with an advanced self-maintenance function to extend the battery life. Depending on the battery charge, it will automatically perform a self-discharge operation after one month of storage. After this self-maintenance, the battery pack will enter sleep mode and maintain 30% of its charge capacity." I spoke over the phone with two EGO customer service representatives, and both said that it wasn't a problem that my battery wasn't self-discharging and that it wouldn't effect the battery life if the battery wasn't self-discharging while in storage. I felt confused after this because the manual seems to indicate that the self-discharge operation has something to do with extending the life of the battery. But, since two EGO customer service reps said that the battery is fine and won't have a shorter life span even though it doesn't self-discharge, I'm currently assuming that the battery is ok.
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(a)Typical Engineer

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For those who are finding their battery packs at full charge after a month or more of storage, you have two options: 1) troubleshoot with Ego tech support (possibly replace), or 2) intentionally recharge to only 50%. 

If you have the rapid charger, that is easy, charge until you have two solid lights, and you're at about 50%. 

For those that only have the standard (slow) charger, you can "guess-ti-mate" by charge time.  If you battery normally  takes 20 minutes to charge, then cut that by 50% to 10 minutes.  For larger packs, if it takes 45 minutes, just charge it for 20-25 minutes.  Or if you're handy with a volt meter, charge it to 51.6V (which is the measure voltage that four of my batteries dropped to after the self discharge mode had kicked in).

The bottom line is that Lithium cells do NOT like to be held near or at MAX voltage (4.2V per cell), or 58.8V for an Ego battery.  Leaving it charged below that can only extend your battery life.
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Erik

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I picked up the Snow Blower last winter with 2 5.0 ah batteries last winter. After the snow was done they sat for 2 mos or so. I bought a backpack blower so I got the batteries out to charge, they charged pretty quick it didn't seem they were down to 30% or even close, possibly almost full charge.

I still have fall yard work and I'm sure by the time i try to leave them sit for 30 days it will snow right before I have tested them. EGO why couldn't you have put a real battery meter on these batteries and not just a button? Everything now days from power tool batteries to electric toothbrushes have better indicators then just a button!
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szwoopp, Champion

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The one item lacking in their superior battery technology
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Blue Angel, Champion

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Agreed and agreed!
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FatStripe

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This reply was created from a merged topic originally titled Battery discharges to zero in storage..

The 2.5Ah battery that came with the trimmer I bought last April will continuously flash green when it is in storage. It will also flash green on the trimmer when the trimmer is not in use, but goes solid green once the trimmer is turned on. I'm wondering if this is normal.

If it is in storage, the battery will deplete itself completely (no light at all)...usually in less than a week. Recharging initially is difficult. The charger will repeatedly click (on & off?) and the fan pulsates between a high and low speed. The indicator on the battery is flashing rapid red during this initial charge.

After letting it sit like this for a couple of minutes I can pull it off the charger and the usual green flashing light reappears. Once that happens, I can place it on the charger and the normal charging cycle begins with the battery flashing green/orange/red until charged. When the charger turns off, the battery starts that continuous flashing green again.

It doesn't sound like I'm getting the same experience with my battery as others are
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(a)Typical Engineer

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I had the exact same issue and Ego warranty replaced the battery. The root cause is the BMS (battery management system) is taking the battery charge down with the self maintenance mode, but then is erroneously continuing until the entire battery is completely depleted.
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JohnH

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This reply was created from a merged topic originally titled Battery self-maintenance mode?.

So the battery manual states that the batteries will automatically discharge to 30% charge and enter sleep mode after 30 days of storage. The charger manual also states that if you leave the battery on the charger, the battery will perform self-maintenance and drop to 30% capacity.

I have not experienced the batteries going into sleep mode after about 60 days of storage. I have one 7.5 Ah and two 5.0 Ah batteries for the snow blower and lawn mower. I last used all three batteries in early February on the snow blower and fully charged them at that time and left them stored off of the chargers. I then used the three batteries in May without re-charging when I started mowing again, expecting the batteries to be depleted much more quickly than a full battery. All three of the batteries lasted the equivalent of a full charge while mowing, which is great for holding a charge, but I really wanted them to be in sleep mode.

I have observed the charger putting the batteries into sleep mode after 30 days and the 4 green lights on the charger all flash simultaneously to indicate the mode rather than constantly green at full charge, as stated in the manual.

Is there a way to force the charger into maintenance mode without waiting the 30 days? I'd like to put the snow blower batteries into sleep mode without "wasting" one of the chargers for the 30 days waiting for it to put the battery into sleep mode. The LiPo chargers for R/C models have this feature.
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(a)Typical Engineer

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Summary: The "self-maintenance" mode is completely self contained in the battery, and has nothing to do with the charger.

The US manual does not say anything, but the UK/Europe manual says the "Power indicator flashes green every two seconds."  The one time I grabbed a 2.0 AH battery, I did notice that the end cap was warm, therefore it had entered self-maintenance mode, but the battery LED was NOT flashing, so this is likely a UK/Europe only feature that may or may not come to the US.

Both the US/UK manuals say nothing about being able to force a battery into self-maintenance mode.

Both US/UK manuals also state that the charger lights do this:

STANDARD charger:
Green LED on the Charger
Intermittently quick flashing

RAPID charger:
LED ON THE CHARGER [LED1, LED2, LED3, LED4]
Intermittently quick flashing in green

That the ACTION is: Battery pack is performing self-maintenance or in sleep mode.
Reinstall the battery pack on the charger to recharge it fully.

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