# 18volt dewalt battery auto tune for longer life



## Edrick (Jun 6, 2010)

Pretty sure you can't over charge those batteries.


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## juanesq (Aug 3, 2011)

Your right!! So the auto-tune is a bluff.


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## gilbequick (Oct 6, 2007)

The auto tune was a feature that came out before the lithiums, designed for the nicd batteries. What it did was discharged the batteries to a safe voltage/cell and then recharged the pack. This prevented a memory build up that nicds can do. I've only seen the auto tune mode come on a couple of times, I'm not sure how often it's really supposed to come on.

Sometimes you'll see guys take a pack that needs recharging and run it in their drill until the drill wont run anymore. Don't do it, it isn't good for the pack. That discharges the cells to a voltage/cell that is horrible for the cells. Just use the pack like your normally would in the tool until you notice the power dropping off, then recharge them like normal.

For the lithium packs, when the pack cuts off, don't try to use it anymore and recharge it.


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## juanesq (Aug 3, 2011)

Thankx for the info. But, how do you know when the auto tune mode is in effect? If it got something to do with the way the little red light blinks, the diagram on the charger sticker indicates other functions?
Honestly, i tried the lithiums and I hate them just because they stop working when battery low. I guess its almost time to buy a new 18v battery!


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## stryker21 (Jan 30, 2010)

From Dewalt website
Using Automatic Tune-Up™ Mode
The Automatic Tune-Up™ Mode equalizes or balances the individual cells in the battery pack
allowing it to function at peak capacity. Battery packs should be tuned up weekly or after 10 to
20 charge/discharge cycles or whenever the pack no longer delivers the same amount of work.
To use the automatic tune-up mode, simply place the battery pack in the charger and leave it for
at least eight hours. The charger will cycle through the following modes.
1. The red light will blink continuously indicating that the 1-hour charge cycle has started.
2. When the 1-hour charge cycle is complete, the light will stay on continuously and will no
longer blink. This indicates that the pack is fully charged and can be used at this time.
3. Whenever the pack is left in the charger after the initial 1-hour charge, the charger will begin
the Automatic Tune-Up™ Mode. This mode continues up to 8 hours or until the individual cells in the battery pack are equalized. The battery pack is ready for use and can be removed at any time during the Tune-Up™ Mode. 4. Once the Automatic Tune-Up™ Mode is complete the charger will transition to a maintenance
charge; no indicator light shows the completion of the Automatic Tune-Up™ Mode.
NOTE: A battery pack will slowly lose its charge when kept out of the charger. If the batery pack
has not been kept on maintenance charge, it may need to be recharged before use. A battery
pack may also slowly lose its charge if left in a charger that is not plugged into an approporiate
AC source.


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## Butt Splice (Aug 28, 2011)

Respect the hot battery, and don't completely drain it. Mission accomplished.


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## chewy (May 9, 2010)

Get a Milwaukee M18 with battery indicator lights.


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## oww-is-that-hot? (Jun 26, 2011)

juanesq said:


> Thankx for the info. But, how do you know when the auto tune mode is in effect? If it got something to do with the way the little red light blinks, the diagram on the charger sticker indicates other functions?
> Honestly, i tried the lithiums and I hate them just because they stop working when battery low. I guess its almost time to buy a new 18v battery!


Yeah that's all you do is leave it on the charger for at least 8 hours. It definitely works for my porter cable batteries. 7-8months old and still like new.


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## captkirk (Nov 21, 2007)

chewy said:


> Get a Milwaukee M18 with battery indicator lights.


 I miss that feature, i wish makita would do it.


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## nitro71 (Sep 17, 2009)

juanesq said:


> Thankx for the info. But, how do you know when the auto tune mode is in effect? If it got something to do with the way the little red light blinks, the diagram on the charger sticker indicates other functions?
> Honestly, i tried the lithiums and I hate them just because they stop working when battery low. I guess its almost time to buy a new 18v battery!


That's because the tool is stopping before you ruin the battery. On Nicads the tools just let you go till you kill your battery pack.


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