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  • #16
    Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

    This Battery University page discusses lithiums at length. Storage should be at 40%, lots of good info.
    http://www.batteryuniversity.com/parttwo-34.htm

    Some points of interest in the article were, these batteries do not do well when run completely down before recharging, should not be stored fully charged and if they have a fuel guage, completely discharge every thirty cycles. Does not sound like a good battery for a cordless tool. I have been storing my Ryobi lithiums fully charged, and running them all the way down when in use. This thread and contributions have help educate me, thanks.
    Last edited by Frankiarmz; 01-27-2010, 01:04 AM.

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    • #17
      Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

      Originally posted by Frankiarmz View Post
      This Battery University page discusses lithiums at length. Storage should be at 40%, lots of good info.
      http://www.batteryuniversity.com/parttwo-34.htm

      Some points of interest in the article were, these batteries do not do well when run completely down before recharging, should not be stored fully charged and if they have a fuel guage, completely discharge every thirty cycles. Does not sound like a good battery for a cordless tool. I have been storing my Ryobi lithiums fully charged, and running them all the way down when in use. This thread and contributions have help educate me, thanks.
      Yeah Frankie. That's a link that DRC-Wartex had geared us to on the first page of this thread. Check out one of my posts from the end of that first page - it has all the different lithium-ion-related stuff condensed into one post. Thanks for the heads up though.

      What we're/I'm trying to sort out is what the drain/discharge rate is of these lithium-ion batteries with the battery monitoring circuit to them. I'm wondering what the rate of discharge is, and whether Ridgid batteries that are equiped with these are having all these issues because of a heavy rate of drain when in storage.

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      • #18
        Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

        I think it's gonna be very difficult to determine with any accuracy the discharge rate given the variables involved. I mean even if you know the discharge rate of the circuitry used, wouldn't indivdual chemistry of the given battery change that result over time? I would think temperature where stored would also factor in there?
        I understand that you are trying to determine if you store the battery for let's say from one to three months at around half capacity, will the circuitry discharge to a dangerously low condition.
        I would feel safer knowing a voltage range to check for, rather than a formula involving discharge over time. I know this works for NiCads, when an 18volt battery goes below lets say 15volts it's time to charge it up. I don't know if the same would work for the lithiums?

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        • #19
          Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

          That's what I want to get to the bottom of.

          I think that the discharge rate of the circuitry would be a relative constant. Yes, the batteries' "...indivdual chemistry of the given battery change that result over time..." would affect things, but that would only affect the battery capacity. The timeline until a full drain would get shorter, as a battery's capacity becomes degraded. But I would think that the circuit's discharge rate (amount of milli-Ah's used) would be the same.

          Yeah, I get what you're saying Frankie. But we know that these lithiums are finicky. I believe that we already know what to do for the lower voltage range, and that can be adequately/accurately checked with a multimeter.

          But it's the storage timelines that I think we haven't really explored with these. We need to have an upper and a lower threshold for getting these suckers charged maybe, if the monitoring circuit is discharging them too rapidly.

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          • #20
            Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

            Originally posted by canucksartech View Post
            That's what I want to get to the bottom of.

            I think that the discharge rate of the circuitry would be a relative constant. Yes, the batteries' "...indivdual chemistry of the given battery change that result over time..." would affect things, but that would only affect the battery capacity. The timeline until a full drain would get shorter, as a battery's capacity becomes degraded. But I would think that the circuit's discharge rate (amount of milli-Ah's used) would be the same.

            Yeah, I get what you're saying Frankie. But we know that these lithiums are finicky. I believe that we already know what to do for the lower voltage range, and that can be adequately/accurately checked with a multimeter.

            But it's the storage timelines that I think we haven't really explored with these. We need to have an upper and a lower threshold for getting these suckers charged maybe, if the monitoring circuit is discharging them too rapidly.
            Given the choice between trusting whatever the manufacturer gives regarding discharge rate and storage periods, and what voltage can be clearly read with a good volt meter, I would go with the later. We have been given inaccurate information regarding the AMP hours of the lithium batteries when they were first introduced, so my confidence is a little shaky. If you had the time prior to leaving for these extended periods, you could check the discharge rate in volts yourself. You said your wife could charge the lithiums up if necessary, and I'm sure she could also use a volt meter to determine at least the resting voltage of each battery.
            I agree that the information you are requesting is both useful and necessary, I just don't know if it will be forthcoming and trustworthy?

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            • #21
              Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

              Bleh, one of you just send me a fully charged 3ah battery and I will measure it for you. I will ship it back at my expense. Batteries are 2.8 Ah BTW, and NO, Ridgid/Milwaukee will not admit to this.

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              • #22
                Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                Sorry, no offense, Wartex, but I won't be shipping out a battery of mine.

                I thought you had some of these? I thought you owned some of the Ridgid cordless tools, which you did comparison testing on with some of your other tools?

                Worst off, you've got to have an HD near you, where you could pick up a kit with some lithium-ion batteries.

                And/or, if there's someone else on here who has these batteries, and can do this same testing on their stuff and let us know. It would be much appreciated.

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                • #23
                  Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                  Why don't you just go buy one and return it?

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                  • #24
                    Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                    Originally posted by Kanxrus View Post
                    Why don't you just go buy one and return it?
                    Because taking stuff apart and desoldering/resoldering wires might look suspicious to a service center tech when the next sap buys this kit and brings it in for service? Also some BMS "lock out" if you cut off one of the cells (Makita, for example).

                    I also don't screw HD out of merchandise by "testing" and then returning. Whatever I test I sell as "used" on classifieds/ebay/to friends or keep. I don't fry a battery and then play stupid at HD service desk

                    canucksartech - not so dedicated to find the truth any more? It costs $7 to ship a battery to canada via USPS First Class mail. Doesn't even have to be a new one. I'm not putting $250 on hold so I can do all the work for you after your shenanigans here. I can help you if you help me.
                    Last edited by DRC-Wartex; 01-27-2010, 11:16 PM.

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                    • #25
                      Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                      One of the members will donate a Ridgid battery for measurements. I will post a link to his website with results.

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                      • #26
                        Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                        Wartex, for exactly the same reasons as you mentioned in your post/explaination to Kanxrus as to why you wouldn't buy one, and no offense on this, I wouldn't ship it to you to do this. I would have no control, no guarantees, and no say over what was going on. I would have no options available to me if something went sideways. And, as the saying goes, "I was born at night, but not last night" - it's got nothing to do with "...not [being] so dedicated to find the truth any more..." as you state.

                        Besides, I had thought that you had these tools, and that my understanding was that you've tested these batteries before and compared these Ridgid batteries to DeWalt, Makita, Bosch, etc.; hence my reasoning that I thought you would have one of these batteries on hands for testing.

                        Nevertheless, I appreciate any further info we can gain from this, and whoever your annoymous battery donator is, I'm glad to hear that we can get some testing results out of this, as the info definintely doesn't appear to be coming from Ridgid (Josh? ProBrand?). Please post and let us know once numbers/results on the drain from the battery monitoring circuit is measured/figured out.

                        Thanks.

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                        • #27
                          Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                          Originally posted by canucksartech View Post
                          Besides, I had thought that you had these tools, and that my understanding was that you've tested these batteries before and compared these Ridgid batteries to DeWalt, Makita, Bosch, etc.; hence my reasoning that I thought you would have one of these batteries on hands for testing.
                          I don't keep every tool/battery of all manufacturers at all times, that's just retarded, I don't own a warehouse. I DID compare cycle life and discharge currents and sold the stuff I don't need. One thing I can can tell you for sure tho, I will never own a tool that uses Moli Energy batteries. Now that they are switching to samsung, I might reconsider.

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                          • #28
                            Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                            Anything further on this??

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                            • #29
                              Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                              The "good Samaritan" did not deliver as promised. But that's ok, I have an M12 battery sitting with Fluke 289 connected taking voltage samples every several minutes, I want to see what happens after a week. Results will be on my blog.

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                              • #30
                                Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                                Anything fresh on this issue??

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