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  • #16
    Re: Battery Memory Reseting?

    is he taking them apart and putting new calls in .

    i took one 18v to a battery place and had it rebuilt and the cells they put in were lighter in weight then the old ones . the rebuilt held up for 1 1/2 yrs ,not worth the $50 .

    i Waite until Lowe's has them on sale 2 for $99
    Charlie

    My seek the peek fundraiser page
    http://observatory.mountwashington.o...nal&fr_id=1040


    http://www.mountwashington.org/weather/conditions.php

    new work pictures 12/09
    http://public.fotki.com/hvachawk/

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    • #17
      Re: Battery Memory Reseting?

      He sells brand new in the pack batteries and tools too. We've always wondered how he sells so cheap! Even came out and asked him if they were hot, he says no! I know one of the DeWalt big shots and he's heard of him too but never has been able to figure out how he sells cheaper than the stores can buy. Needless to say he does a land office business LOL.
      My dead 18v XRP shows a date code of 11 months old WHEN I BOUGHT IT!! Maybe that's how he gets em so cheap, they are new but sitting for months and months. Guess i'd better ck them from now on.

      Well, I'll get my son's mini tiny tiny torx bit and take a few apart and see if I can come up with some way to test them. Just hate seeing all of them sitting here dead.

      Mark
      Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

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      • #18
        Re: Battery Memory Resetting?

        i had mine apart to fix it before .if you get new cells i don't know how you would solder the cells together ,they use a spot welder


        and it is nice to know about the date to look for it.
        Charlie

        My seek the peek fundraiser page
        http://observatory.mountwashington.o...nal&fr_id=1040


        http://www.mountwashington.org/weather/conditions.php

        new work pictures 12/09
        http://public.fotki.com/hvachawk/

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        • #19
          Re: Battery Memory Resetting?

          Spot welded? That's not what I was hoping to hear. Hmm, maybe I can figure out something.
          Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

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          • #20
            Re: Battery Memory Reseting?

            Originally posted by mtburdick View Post
            Hi all,

            Im haveing issues with my ridgid cordless set right now. Im finding that my batterys last only for a few minutes if im lucky useing the sawsall. And im lucky if i can even cut a 2x4 with the circular saw. Is there any way to reset the memory on the batteries? or do i have to replace them?
            Thanks in advance.

            Usually if you give them a serious knock with a 5# hammer they will forget everything they ever knew...at least that's what I find with apprentices


            Just kiddin of course, I would never risk damaging a good hammer on an apprentices' thick skull.
            ---------------
            Light is faster than sound. That's why some people seem really bright until you hear them speak.
            ---------------
            “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
            ---------
            "Its a table saw.... Do you know where your fingers are?"
            ---------
            sigpic http://www.helmetstohardhats.com/

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            • #21
              Re: Battery Memory Reseting?

              Originally posted by Shade Tree View Post
              Hello MT I’m not familiar with the tool you are having trouble with, but from the discussion it sounds like Ni-Cads. I’m a retired electronic technician and use a lot of Ni-Cad batteries. After fighting them for many years, I have come to some understanding of getting along with them. Here are a few ideas

              Ni-Cads like to be kept fully charged, kept cool, charged at the 14 hr rate, and not be run all the way down.

              The 14 hour charge rate is capacity (ampere-hours or AH) divided by 10, times 1.4. For example, a 4 AH battery should be charged at 0.4A for 14 hours. The extra 4 hours is for the power lost to heat in the charging process (inefficiency). That is, battery charging is only 60% efficient. Charging a battery for extended periods can pop the safety seal, allowing the electrolyte to escape, seriously reducing its capacity. The fast charge batteries found in high power equipment do not prefer a fast charge, they just tolerate it better than standard batteries. This leads to temperature.

              Ni-Cads are damaged if the internal temperature goes much above 125 deg F. Think about the heat generated when charging. Even more is generated when discharging at a high rate. If you leave a high power tool in the sun on an 80 degree day, the battery temperature could be at 110. Then when you do a heavy cut, the battery internal temp is going to climb way above 125 deg. If the case of a working battery feels warm to your hand, it is plenty hot inside where the electrolyte meets the separator. The inside of my locked truck here in mild Southern Calif is typically 110 deg even on a cool day. In the summer it has gone over 140! Keeping an inexpensive thermometer in your vehicle can be a real eye opener.

              Standard Ni-Cads like to be charged at the 14 hour rate because it strikes a balance between the heat of fast charging and the whisker growth of slow charging (really!). Batteries that are left in the near dead condition or are routinely slow charged grow whiskers of plate material that eventually shorts out the cell. (A battery is a number of cells in series which is wrapped in plastic). Normal charging keeps the whiskers from growing. What Chic did when he jumpered his bad battery with a good one to make it take a charge was to burn away the shorting whisker. I have jumpered mine across a car battery, applying over a hundred amps for a few milliseconds and had them recover. (I wore gloves and safety glasses just in case.) As Tacman mentioned, freezing them can work. Anything that breaks the whisker fixes the problem for a short time. When I worked in the aerospace industry, a co-worker used to throw them on the concrete floor. It is wasted effort though. There are thousands of whiskers growing and the only one destroyed is the one shorting the cell. As soon as another one is long enough the cell is shorted again. By the way, shorting is the most common failure mode.

              The other main failure mode is reverse charging. In power tools, you never have just one cell - even flashlights usually have two or more. When one cell is completely discharged, it becomes reverse-charged by the current flowing from the others if the tool is kept in operation. It may take a charge again, depending on conditions. Even if it does, its AH capacity is reduced so that it is reverse-charged even sooner next time. It will be the first cell in the battery to fail and the symptom will be a battery that won’t hold a charge. Continuing to use the tool will just reverse-charge the next weaker cell.

              So, for those of you still reading: Keep the tool out of the sun as much as possible, stop using it or change the battery pack when it slows down, and recharge it as soon as possible according to the manufacturers instructions, avoiding fast charging if you have the option. If you only have a fast charger, don't try to fully charge it, shoot for 75%. Ni-Cads lose about 1% of their charge per day, so if it sits for many weeks, top off the charge before using it.

              As an aside, the Ni-Cad memory problem is highly over-rated. The only time that occurs is when the battery is discharged to the same partial discharge repeatedly. Think of a walkie-talkie that is used 8 hours a day and has 12 hours worth of battery in it. Every night the battery is recharged and eventually it will develop a memory that resists taking more than 8 hours worth of charge. But, they can often be reconditioned if in not too bad shape.

              Most battery failures are caused by a dead or reversed cell. All the above applies to NiMH cells. They are even more temperature sensitive and will not take a slow charge. Their claim to fame is higher capacity for a given size. Lead-acid Gel-cells are a bit more rugged (and a whole lot heavier).

              And this just scratched the surface!

              Ni-Cads are like women - treat them well and you will have a long, happy relationship.

              Shade Tree
              Lot of good info in Shade Tree's post.

              Unfortunately, most tool chargers don't have a slow charge option.

              However, you can reduce the abuse the batteries by never charging them when they are hot. Also remove them as soon as they are done charging.

              Keeping your batteries in the refrigerator will extend their life, and extend the time they hold a charge.

              Try not to keep your batteries in a hot vehicle. This is true with Lithium Ion too. Lithium battery life will be greatly shortened if kept at hot temperatures.

              There are devices that "shock" a battery to try to remove the crystals that form. I've heard mixed results with these. When a cell is abused it is difficult to completely recover it and it will always be the weak link. Never "shock" a lithium battery.

              While you can dismantle a battery and replace the bad cells, it does take some soldering skills and you will still have a mismatch between the older cells and the new ones you just added.

              The reverse charging he speaks of happens when you allow a cell pack to get too low...say leave a pack in a flashlight that runs down. This will toast a cell quick. Never continue to use a pack that is noticeably low on power and never leave a pack in a flashlight.

              Despite what many people think regarding NiCd memory and the superiority of NiMh, NiCds are actually more robust than NiMh. They can handle higher temps and are easier to recover when they've been mishandled or been left sitting. Lithium blows both away. For one thing, it is considerably more efficient. If you put 3000mAh into a Lithium cell, you will be able to draw nearly that much from it. In a NiCd or NiMh you might lose 30%.

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