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

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

    Okay, Wartex (and any others on here with battery/chemistry/electronics engineering knowledge), I have a serious question for you. Something with lithium ion batteries has got me perplexed, and I'm curious as to if this query of mine might also help out others that could be starting to develop lithium-ion battery issues.

    I was doing some homework online to try to appease my curiosity, and I found this on Wikipedia ( http://en.wikipedia.org/wiki/Lithium-ion ):
    Charging procedure

    Stage 1: Apply charging current limit until the voltage limit per cell is reached.[42]
    Stage 2: Apply maximum voltage per cell limit until the current declines below 3% of rated charge current.[42]
    Stage 3: Periodically apply a top-off charge about once per 500 hours.[42]
    I know there is a huge variance in the uses and construction and voltages and all that jazz for the different types of lithium-ion batteries in different types of uses (electric vehicles, laptops, cell phones, power tools, etc.). But my question basically is this: What should be the frequency, if any, of "top-off charges" that we should be doing with these Ridgid power tool batteries?

    I'm asking this because I saw this reference (and I've seen others online) to this 500 hour number (20.83~ days) for top-off charging - but I'm not 100% as to if this number refers to a certain type of lithium-ion batteries, or if it applies to all of them but is just a lower number, say to try to keep the battery charge above a 70% or 90% level. With the type of cells that Ridgid is using in these power tool batteries, and the "smart/monitoring circuit" or so that are installed in these batteries, there appears to be this slow-drain issue. Many people have regularly piped in on here about lithium-ion battery failure - although I myself am convinced that the recent (past 3-4 months or so) complaints sound like they're due from a bad production batch/run from the factories.

    But with this smart-monitoring circuit, I understand that we do have to be careful of the slow-draining of voltage from the cells in these battery packs. However, I don't remember anyone on here, nor Ridgid themselves, stating as to what the "normal" discharge rate is that this smart-monitoring circuit pulls from these battery packs/cells. What I want to know, is that if someone has a power tool, and they're more of a homeowner/DIYer that only uses their power tools a couple times per year, and not multiple times per week like many on here, when should they worry about doing a top-off charge of their battery packs so that they don't have to worry about the discharge rate draining the cells' voltage towards zero, and basically toasting their batteries?

    I understand that LI battery cells have been designed to normally only have a 5% per month charge loss. Well, what of the remaining charge (20%, 10%, or lower) is that dreaded "lower limit" or so to speak, when you have discharged a battery cell beyond the point of no return?

    If the smart monitoring circuit has a discharge rate of say "X" amount of milliamps/amp hours, at a set voltage, and the batteries/battery cells themselves have a certain max/nominal voltage and a "Y" number of the maximum milliamps/amp hours of power to them, then how long would it take (with all things being equal and working within the norms), how long would it take for the smart monitoring circuit to discharge the battery to a dangerously low-drained state?

    I'm asking this, because this 500 hour number seems excessively short (only 21-ish days), but not if it's referencing a 90% number or something like that. And I myself have always used my tools to the point that I've needed to charge my battery packs at least once a month or so at the minimum (some months it may be daily, and other months could be less). But, I've never had them sit for long periods of idle time, but I'm coming up to a point employment-wise where that may be the case, with me being away from home for long stretches of time. Since I don't recall Ridgid or other manufacturers saying that with these smart-circuit lithium-ion batteries they should be topped-off every 3 or 6 or "X" months, then what does the math of the situation tell us we should be doing?

    I don't recall any conversation on here where we seriously looked at this issue - we haven't really discussed some sort of a discharge timeline or anything like that. Also, with tools sitting on the shelves at HD, and some people purchasing these recently and having battery issues right from the get-go, I remember Wartex and a few others stating that this could be an issue of these smart monitoring circuits toasting the batteries right from the get go, because of sitting for excessive amounts of time and getting overly discharged.

    And/or, if any of the Ridgid staffers on here might have, or could get, an authoritative answer for us from your/TTI's engineering departments, I think this could be a big help for customers. It's not something that's in any manuals for these lithium-ion products, some sort of a definitive timeline, so...let's start the conversation on it.

    Long post from me (yet again, I know), but it's something that's picked my curiosity.

  • #2
    Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

    I like the way you started off by saying "seriou", as if you are a joking kind of guy. From my reading on the battery section of "candlepowerforums.com", I am familair with the term deep discharge, which is what I think you are talking about. I'm a DIY'r/homeowner, and after reading posts on this site, I've gotten into a habit of checking all my batteries once a month and charging if the voltage goes below a certain level.Cordless lawn tools don't get used for many months, but they need to be charged during the off season. Sometimes I don't use a cordless tool battery for several months, but I still check it with a good volt meter and the possibly run it down in a tool, or just charge it up. Glad you asked the question.

    Comment


    • #3
      Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

      Originally posted by Frankiarmz View Post
      I like the way you started off by saying "seriou", as if you are a joking kind of guy. From my reading on the battery section of "candlepowerforums.com", I am familair with the term deep discharge, which is what I think you are talking about. I'm a DIY'r/homeowner, and after reading posts on this site, I've gotten into a habit of checking all my batteries once a month and charging if the voltage goes below a certain level.Cordless lawn tools don't get used for many months, but they need to be charged during the off season. Sometimes I don't use a cordless tool battery for several months, but I still check it with a good volt meter and the possibly run it down in a tool, or just charge it up. Glad you asked the question.
      Thanks Frankie. Yeah, I figured I'd better start off with a "serious" note, due to the past issues.

      No, I get what you're saying about deep-discharge and what not, and I know that is something that we need to look out for, but what I'm looking for is specifics. I'm wondering if there is a deadline for when we need to look at getting these batteries re-charged/topped off. For example, depending on what the math works out to, I want to find out the following:
      • 1.5 Ah ("compact") Ridgid 18 volt lithium ion batteries - must be re-charged within "X" months, if stored at 0 degrees celcius / 32 Fahrenheit and above.
      • 1.5 Ah ("compact") Ridgid 18 volt lithium ion batteries - must be re-charged within "X" months, if stored below 0 degrees celcius / 32 Fahrenheit.
      • 3.0 Ah Ridgid 18 volt lithium ion batteries - must be re-charged within "X" months, if stored at 0 degrees celcius / 32 Fahrenheit and above.
      • 3.0 Ah Ridgid 18 volt lithium ion batteries - must be re-charged within "X" months, if stored below 0 degrees celcius / 32 Fahrenheit.
      Something like that. And/or, I'd also like to see these same number specifics for the 24 volt XLi batteries, too.

      I too check on my batteries monthly or so, and charge them every month as needed. But, if I'm going to be going away for a period of 2 to 3 months at a time, even upwards of 4 to 6 months maybe, I won't be able to check on them. So, for myself, what I'll need to do is sort out a particular timeline, and say to my wife, charge them on this particular date.

      And, I know that many users are not as finicky as you or I or others on here about checking stuff, and maintenance, etc. And, like I mentioned earlier, many users might be going 2 or 3 or 6+ months without using their tools. So when do we need to worry about non-use damaging our batteries? That's what I'm sleuthing for.

      Comment


      • #4
        Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

        That's a long time to be away, I hope everything will be alright for you. I think it's great that your wife would be willing and able to do something like check battery status. I remember someone posting a while back the proper low voltage for different batteries at which time they should be charged. I expect you will get a good response. Best of luck in your travels. Frank

        Comment


        • #5
          Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

          Obviously, the battery challenge is one well worth discussing. But the information available never seems to be from a scientific source and everyone has an opinion, with quite a lot of difference, I might add.

          I've been using NiCads for as long as I remember in my photography work and Ham Radio hobbies. One of the first consumer products on the market was from GE with thier little 4-cell, AA chargers. Their recommendation was to keep them plugged in all the time. Absolutely wrong, as you'd "cook" the chemistry right out of the batteries within a matter of a few months.

          I then started "draining" my NiCads rather then "top them off". I had pretty good luck with most batteries lasting four or five years or more. But, you had to be careful not to drain them down to less than about a half-volt per cell, as you ran the risk of pole-reversal.

          With Ridgid NiCad packs, I just do a recharge every couple of months. As a home owner/hobbyist I don't use them everyday; but with working on the house they do get use at least a few days or more each month. I never drain them down to nothing... just to a point where they really won't drive the tool efficiently. My batteries are almost five years old now and are still working great.

          I only own one Li-Ion tool, the little 12-volt compact drill-driver that Ridgid first introduced a couple of years ago. Iirc, the manual says to not run them down to nothing. But on my laptop, which also uses Li-Ion, the manual says to NOT top them off. Something of a conflict in my mind I think!

          The fact is, the 12-volt came with two batteries and although this tool is used quite often (I like it's handy size), I have difficulty draining the darn battery...it just keeps on going and going. But, I have taken to charging both batteries every couple of months.

          Big deal for me is to NOT leave the batteries in any place where extreme temperatures may effect them. From what I've read/understand, Li-Ions will drain rapidly if left in the cold; so, I never leave them in the vehicle overnight.

          NiCads appear to be more stable than Li-Ions in cold weather, but the shelf-life/non-use of them is a detriment as they drain much faster than Li-Ions by comparison. They do withstand "load" better than Li-Ions, in my experience. Li-Ions if subjected to a high-torque load, will cause the battery to heat up much faster than NiCads will; and, will shutdown quickly. But what is questionable to me, is whether that's the battery itself, or the safety/protection circuitry incorporated in the battery. As you may recall, early experimentation with Li-Ion batteries in computer operations have caused fires. Allegedly these earlier batteries lacked "overload" protection and rapid drain or charge ("rapid" being a subjective term here) would cause the Li-Ion chemistry to reach it's flash point rather quickly!

          While I'm sure that some "scientific" approach may well prove to be a measured exercise to gain absolute optimum performance, I'm not exactly sure of a source for trusting information. I do know what my own experience has been and I've left voltage readings behind as a battery maintenance routine. But that said, I'll only buy Ridgid and go with their LLSA as an insurance policy... just in case I'm wrong!

          So my conclusions have been that Li-Ion are not good in cold weather, shouldn't be left in frigid conditions ever, and shouldn't be subjected to constant high-torque/rapid drain situations without expecting their circuitry to shut down the battery. NiCads, will drain faster in storage and are best if used often. Left for occasional use like with us home owners, we'll more likely to see shorter battery life than those who use them everyday. NiCads should never be drained down and then just left uncharged as they will go into reversal an thus be useless. Not sure about Li-Ion, but my own routine has been to run both types until they they show weakness and then to charge them.

          I'm sure there will be any number of opinions, just as those who write the instructions can't seem to reach consensus on what the best procedure is.

          CWS
          Last edited by CWSmith; 01-23-2010, 11:10 PM.

          Comment


          • #6
            Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

            Originally posted by CWSmith View Post
            Obviously, the battery challenge is one well worth discussing. But the information available never seems to be from a scientific source and everyone has an opinion, with quite a lot of difference, I might add.

            CWS
            Heh, I see this a lot. If by "scientific source" you mean a bunch of dudes in white coats who finished university, they use the same math and equipment as any hardware hacker or electronics engineer.

            Measuring battery specs is not rocket science. You have to be careful when generalizing "everyone has an opinion" because technical specs and proper measurements with a properly calibrated multimeter are not opinions. They are facts, scientific facts. There is also accepted knowledge and technical papers that agree (go read some NiCd chem patents) that you can find online.

            The difference between an opinion and a fact is that facts are repeatable and verifiable. I will start posting data dumps directly from my equipment so we can finally distance from "Wartex's opinion".

            For example, Dewalt 18v fluorescent light runs 4 hours on a new 2.4 Ah NiCd battery. My multimeter shows 580-600 mA consumption (video available).
            2.4 Ah / 4 h = 0.6 A, just like measured. This is a scientific fact. I can take a Ridgid battery and measure quiescent currents in the BMS just as accurate and predict when it's going to overdischarge. I can charge it with ampmeter connected with my logging multimeter and tell exactly how much I pumped into it, and measure temperature with my thermal imager and calculate how much is wasted in heat.

            NiCd should be stored discharged. Li-Ion should be stored 40%+ charged, both at 20C. Li-ion lasts longer if shallow-cycled. I top-up my li-ion batteries every 3 months (ones I don't use) leaving them for a day on a charger to balance the cells, and ones I use I recharge right after use or when I hear RPM drop (not when they are completely dead).

            No all Li-Ion is equal. Nanophosphate works in cold weather with reduced curret output. Manganese spinel freezes to death at -10C.

            Comment


            • #7
              Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

              Originally posted by DRC-Wartex View Post
              NiCd should be stored discharged. Li-Ion should be stored 40%+ charged, both at 20C. Li-ion lasts longer if shallow-cycled. I top-up my li-ion batteries every 3 months (ones I don't use) leaving them for a day on a charger to balance the cells, and ones I use I recharge right after use or when I hear RPM drop (not when they are completely dead).

              No all Li-Ion is equal. Nanophosphate works in cold weather with reduced curret output. Manganese spinel freezes to death at -10C.
              Okay. That's some of what I wanted to see - lithium-ion should be stored at approximately 40% of it's charge/voltage capacity, but what is the minimum charge percentage that you wouldn't want it to drain below - 30%, 20%, 10%?

              Now Wartex, you say that you "top-up my li-ion batteries every 3 months (ones I don't use)" - which batteries are these? The DeWalt nano's, or another brand, or do you have any Ridgid ones too that you do this for?

              Where I'm trying to get to is finding that minimum threshhold. You've said that they should stay above 40% - okay, great. But is 20%/10%/etc. or so the dreaded point-of-no-return for smart-monitored liths, where they won't accept a charge anymore? If we need to strive for 40%, that's a good number to work forward on, and we can use that also as a recommended timeline, but what is the absolute minimum also?

              For example, I don't think that Bosch lithium-ion batteries have the monitoring circuit in the batteries themselves - I think they're in the tools and the chargers, as I've noticed no self-discharge at all relatively when I have those being stored. If I'm correct with this, and 40% is the minimum goal that we should look for, and with 1%-5% loss per month, then Bosch lithium-ion batteries need to be recharged/topped up after 12 months or so of non-use/storage, from a safe perspective, but at a minimum, every 2 to 3 years or so. If I'm correct in assuming that the Bosch batteries don't have the energy-depleting monitoring circuit in them.

              That's cool. That's fine.

              But for the Ridgid batteries, we know that the monitoring/smart circuitry is in the lithium-ion batteries themselves. Well, what is the drain rate that this circuitry puts on these batteries when in storage? How long will it take before this circuitry tends to over-discharge the battery below this safer 40% level, and then how long before it goes into the red zone? IE - how many milliamps or whatever does this circuitry drain at, and depending on the timelines involved, it will then eat away "X" percent of the battery charge per month.

              Thanks for all the input so far you guys.
              Last edited by canucksartech; 01-24-2010, 01:00 PM. Reason: Additions/changes

              Comment


              • #8
                Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                Wartex,

                Interesting.

                So those of us who use our NiCads on rare occasion, and/or not at all, should find the batteries in great shape after long-term storage?

                Yet, I have read and experienced that NiCads loose their charge much more rapidly during storage than thier Li-Ion or NiMH counterparts. So, at what point does your instrumentation tell us that the battery's voltage will drop below a level where it can be recharged. And, is the so-called "pole-reversal" that is often reported from such unattended "discharged" storage, only a myth?

                I don't profess to have gone to the lengths that you proclaim, I only spoke of my experience (which forms "my opinion" on ). And yes, there are many papers on the internet, but like instruction materials, some are in conflict with others. Perhaps you could direct us all to those that are more proven to be the truth. I'm sure we would all appreciate and benefit from your own scientific research of the subject.

                Thanks,

                CWS
                Last edited by CWSmith; 01-24-2010, 01:07 PM.

                Comment


                • #9
                  Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                  CWS

                  http://www.buchmann.ca
                  http://batteryuniversity.com

                  Comment


                  • #10
                    Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                    Okay, there's some great information available on there, but for the purposes of this thread, I want to stick to the specific Lithium-Ion stuff:
                    "Lithium-ion works within the discharge temperature limits of -20°C to 60°C (-4°F to 140°F). The performance is temperature based, meaning that the rate capability at or below -20°C is reduced due to the increased impedance of the electrolyte. Discharging at low temperatures does not harm the battery. Lithium-ion may be used down to -30°C (-22°F) with acceptable results. Larger packs will be necessary to compensate for the reduced capacity at these temperatures.
                    It is not recommended to discharge lithium-ion at temperatures above 60°C. A high discharge rates combined with elevated temperatures can cause self-heating, an effect that could permanently damage the separator and electrodes of the cells."

                    "Lithium-ion typically discharges to 3.0V/cell. The spinel and coke versions can be discharged to 2.5V/cell to gain a few extra percentage points. Since the equipment manufacturers do not specify the battery type, most equipment is designed for a 3-volt cut-off.
                    A discharge below 2.5V/cell may put the battery's protection circuit to sleep, preventing a recharge with a regular charger. These batteries can be restored with the Boost program available on the Cadex C7000 Series battery analyzers.
                    Some lithium-ion batteries feature an ultra-low voltage cut-off that permanently disconnects the pack if a cell dips below 1.5V. A very deep discharge may cause the formation of copper shunt, which can lead to a partial or total electrical short. The same occurs if the cell is driven into negative polarity and is kept in that state for a while.
                    Manufacturers rate the lithium-ion battery at an 80% depth of discharge. Repeated full (100%) discharges would lower the specified cycle count. It is therefore recommended to charge lithium-ion more often rather than letting it discharge down too low. Periodic full discharges are not needed because lithium-ion is not affected by memory."

                    Figure 2: Cycle life of lithium-ion at varying discharge levels. (Choi et al., 2002)
                    Like a mechanical device, the wear-and-tear of a battery increases with higher loads

                    "What constitutes a discharge cycle?
                    There are no standard definitions that constitute a discharge cycle. Smart batteries that keep track of discharge cycles commonly use a depth-of-discharge of 70% to define a discharge cycle. Anything less than 70% does not count. The reason of the cycle count is to estimate the end-of-battery life.
                    A battery often receives many short discharges with subsequent recharges. With the smart battery, these cycles do not count because they stress the battery very little...
                    ...Lithium and lead-based batteries do not require a periodic full discharge. In fact, it is better not to discharge them too deeply but charge them more often."

                    "Negatives of the 'smart' [lithium] battery:
                    The 'smart' battery has some notable downsides, one of which is price. An SMBus battery costs about 25% more than the 'dumb' equivalent. In addition, the 'smart' battery was intended to simplify the charger but a full-fledged Level 3 charger costs substantially more than a regular model.
                    A more serious drawback is the requirements for periodic calibration or capacity re-learning. The Engineering Manager of Moli Energy, a manufacturer of lithium-ion cell commented, "With lithium-ion we have eliminated the memory effect; but is the SMBus battery introducing digital memory?"
                    Why is calibration needed? The calibration corrects the tracking errors that occur between the battery and the digital sensing circuit while charging and discharging. The most ideal battery application, as far as fuel-gauge accuracy is concerned, would be a full charge followed by a full discharge at a constant current. In such a case, the tracking error would be less than 1% per cycle. In real life, however, a battery may be discharged for only a few minutes and the load pulses may be very short. Long storage also contributes to errors because the circuit cannot accurately compensate for self-discharge. Eventually, the true capacity of the battery no longer synchronizes with the fuel gauge and a full charge and discharge is needed to 're-learn' the battery.
                    How often is calibration needed? The answer lies in the battery application. For practical purposes, a calibration is recommended once every three months or after every 40 short cycles. Many batteries undergo periodic full discharges as part of regular use. If the portable device allows a deep enough discharge to reset the battery and this is done regularly, no additional calibration is needed. However, if no discharge reset has occurred for a few months, a deliberate full discharge is needed. This can be done on a charger with discharge function or a battery analyzer.
                    What happens if the battery is not calibrated regularly? Can such a battery be used in confidence? Most 'smart' battery chargers obey the dictates of the chemical cells rather than the electronic circuit. In this case, the battery will fully charge regardless of the fuel gauge setting and function normally, but the digital readout will become inaccurate. If not corrected, the fuel gauge simply becomes a nuisance."

                    "The state-of-charge indicator:
                    Most 'smart' batteries are equipped with a charge level indicator. When pressing the 'Test' button on a fully charged battery, all signal lights illuminate. On a partially discharged battery, half the lights illuminate, and on an empty battery, all lights remain dark. Figure 4 shows such a fuel gauge.

                    Figure 4: State-of-charge readout of a 'smart' battery.Although the state-of-charge is displayed, the state-of-health and its predicted runtime are unknown."
                    "How to store batteries:
                    Batteries are perishable products that start deteriorating right from the moment they leave the factory. There are simple preventive measures that battery users can apply to slow the aging process. This paper provides guidelines to reduce age-related capacity losses and how to prime new and stored batteries.
                    The recommended storage temperature for most batteries is 15°C (59°F). While lead-acid batteries must always be kept at full charge, nickel and lithium-based chemistries should be stored at 40% state-of-charge (SoC). This level minimizes age-related capacity loss, yet keeps the battery in operating condition even with some self-discharge. While the open terminal voltage of nickel-based batteries cannot be used to determine the SoC accurately, voltage fuel gauging works well for lithium-ion cells. However, differences in the electrochemistry of the electrodes and electrolyte between manufacturers vary the voltage profile slightly. A SoC of 50% reads about 3.8V; 40% is 3.75V. Store lithium-ion at an open terminal voltage of 3.75-3.80V. Allow the battery to rest 90 minutes after charge before taking the voltage reading.
                    Figure 1 illustrates the recoverable capacity at various storage temperatures and charge levels over one year.

                    Figure 1: Non-recoverable capacity loss on lithium-ion and nickel-based batteries after storage. High charge levels and elevated temperatures hasten the capacity loss."

                    "Lithium-ion batteries deliver full power after the initial charge. Manufacturers of lithium-ion cells insist that no priming is required. However, priming is beneficial as an initial start and to verify battery performance. Excessive cycling should be avoided because of wear-down effect.
                    The internal protection circuit of lithium-based batteries is known to cause some problems after a long storage. If the battery is left discharged after use, the self-discharge will further drain the pack and eventually drip the protection circuit at about 2.5 volts per cell. At this point, the charger will no longer recognize the battery and the pack appears dead. Advanced battery analyzers (Cadex) feature the Boost program that activates the protection circuit to enable a recharge. If the cell voltage has fallen below 1.5V/cell and has remained in that state for a few days, a recharge should be avoided for safety reasons."


                    "While capacity loss during a battery's life cannot be eliminated, simple guidelines minimize the effect:
                    • Keep batteries in a cool and dry storage area. Refrigeration is recommended but freezers should be avoided. When refrigerated, the battery should be placed in a plastic bag to protect against condensation.
                    • Do not fully charge lithium and nickel-based batteries before storage. Keep them partially charged and apply a full charge before use. Store lithium-ion at about 40% state-of-charge (3.75-3.80V/cell open terminal). Lead-acid batteries must be stored fully charged.
                    • Do not store lithium-ion fully depleted. If empty, charge for about 30 minutes before storage. Self-discharge on a depleted battery may cause the protection circuit to trip, preventing a recharge.
                    • Do not stockpile lithium-ion batteries; avoid buying dated stock, even if offered at a reduced price. Observe the manufacturing date, if available.
                    • Never leave a nickel-based battery sitting on a charger for more than a few days. Prolonged trickle charge causes crystalline formation (memory).
                    • Always store a lead acid battery in full-charge condition. Observe the open terminal voltage and recharge the battery every 6 months or as recommended by the manufacturer."
                    Last edited by canucksartech; 01-24-2010, 02:46 PM.

                    Comment


                    • #11
                      Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                      A lot of information.

                      But the main question then, based on all these numbers, is we need to verify/find out what the milliamp draw / discharge rate is of the monitoring circuits that are in these different Ridgid lithium-ion battery packs (1.5 Ah and 3.0 Ah 18-volts, 3.0 Ah XLi 24-volt, 12-volt, etc.)

                      ProBrand or Josh - is this something that you guys can find out for us from the engineers at Ridgid / TTI? I'm not sure if it's "protected" info or not, but it would help us out a bunch with all this.

                      Comment


                      • #12
                        Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                        i can test a 3S pack (milwaukee m12) self discharge, but it has no BMS. if you want to know the BMS draw you'll have to send me one of your batteries, I don't have any 18v rid/milw right now.

                        BOSCH packs 18v have BMS but cells are self-balancing.

                        Comment


                        • #13
                          Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                          The Bosch ones that I was refering to myself are the 10.8 volt stuff from the PS-20 and the PS-40. My sort-of boss has some of the larger 18 volt Bosch stuff, but he says he does notice an ever-so-slight discharge with it. But I don't have that at all with the 10.8 stuff.

                          Does anybody have a Ridgid 18-volt lithium-ion that they can get a reading from the battery's monitoring circuit?

                          ProBrand - and/or Josh - is there any word from Ridgid/TTI engineers on what the designed/estimated/actual power drain is from these monitoring circuits?

                          Worst off, Wartex, could you get one from your local HD to try out? I thought you had some of these?

                          Comment


                          • #14
                            Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                            What about NiMH batteries?

                            Characteristics? Performance? Best way to use and store?

                            Thanks.

                            J.C.

                            Comment


                            • #15
                              Re: Lithium-Ion Batteries: Are issues due to self-discharge? Should we top-up charge?

                              JC, if you follow the second link that DRC-Wartex posted, you can find lots of NiCd and NiMH stuff on there too:

                              Originally posted by DRC-Wartex View Post
                              I'm trying to get this lithium thing sorted out...

                              Comment

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