Battery self-maintenance mode?

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This conversation has been merged. Please reference the main conversation: Isn't the battery supposed to self discharge to 30% after a month?

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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JohnH

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Posted 11 months ago

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Blue Angel, Champion

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John, there's no way to force batteries into storage mode, you just have to wait.
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szwoopp, Champion

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What if  after last use don't recharge the battery.  Storage mode is nothing magical, just a partially charged battery which is a better storage condition.  ( I know the storage mode at 30% is optimal, but 50% is better than 100% and the effect of storage mode is probably minimal)

Is this an accurate statement?
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Blue Angel, Champion

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I would say so. The whole point of storage mode is to reduce the cell voltage to a lower level over long periods of inactivity. Using before storing would accomplish this. Good point!
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William P Tucker

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I have three 5.0 AH batteries for my snowblower. The batteries were all new this past December, and did not get used other then for blower checkout, due to the lack of local snow. In February, the batteries were topped off, removed from the charger, and stored in a inside closet. In July, I reinstalled all three batteries on the charger, to see what state of charge they were in. I found all three to still be fully charged. None of the three had any state of discharge. Once again, I removed the batteries from the charger, and put them all back in the closet. Last week (10/6/17) I purchased a EGO blower, minus the battery and charger, so I took out the batteries once again from storage, to check out the new blower when it arrives. Again, I found all three batteries fully charged. I have placed the batteries back into storage, but this time two of them are installed on a charger. My question is, do the batteries only discharge to 30% if they are on a charger, or do
I have a problem with all three batteries?
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(a)Typical Engineer

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The self-discharge feature is completely built into the battery, so the charger is not required.  You also cannot force a discharge with the charger (like the Li-Po charger features).  About the only thing you can do is to store them in an approximate 30% state.

When I know I'm not going to use my batteries for a while, I intentionally under charge them to about 50% with the rapid charger, since it has the 4 LED indicator system.  If you have the standard charger, the next best thing you could do is measure the overall battery voltage (but I don't know what battery voltage corresponds to 30-50%).

I would not say you have a problem per say.  The self-discharge feature does not appear to be working in your batteries, however, given the opposite situation where by the battery self discharges to 30%, then keeps going until it's completely dead, that's the better of the two problems to have.
(Edited)
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(a)Typical Engineer

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I grabbed my 2.0 AH yesterday and the end cap was warm, so i also measured the temperatures: 85F ambient and 110F, so 25F temperature difference when in self discharge mode.

(Edited)
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William P Tucker

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Well, I called EGO Customer Support on Tuesday (10/10), and explained to the lady what I was seeing from the three batteries. She at first told me the batteries were good to use as is, but I retorted that they advertised something that these batteries were not providing.
I could not be sure if the batteries had been impacted by this suspect problem. She agreed to escalate the problem to their engineering department. I'm currently awaiting feedback from engineering.

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