MSW inverter and cordless drill battery chargers

landyacht.318
landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
in General Solar Power Topics #1
While only partially related to a solar theme, I think there are more electrical gurus here than anyplace else I could think of to pose such a question.

A while back I had to replace the charger that came with my 19.2 volt Porter Cable cordless drill. I'd left it plugged in constantly, and it quit after 3 months.

I posted the following question to Porter Cable but never recieved acknowledgement or a response.

Is it okay to use a MSW inverter to charge PC batteries with a PC charger? I know Dewalt chargers self destruct on a MSW inverter.

I have no other need of a true sine wave inverter and will not buy one just to run this charger.

PC no longer makes the charger model which gave up, and I had to buy a different, newer model from them which doesn't weigh nearly as much, and doesn't seem to get as hot while operating. Unfortunatly this replaccement charger cost nearly as much as the drill kit did, and If I destroy this charger, the drill will become a paperweight. No way will I buy PC anything again.

Thanks
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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #2
    Re: MSW inverter and cordless drill battery chargers

    Unfortunately, MSQ inverters have the chance of destroying equipment. The newer power supplies and electronics are typically now power factor corrected--and should work much better on MSQ--in general. But without knowing (and experimenting) it is probably still impossible to guess before hand which will work or fail.

    If you have a scope, you can check the current profile for large peaks. Or, possibly a Kill-A-Watt meter and monitor power factor and see if it is near 1 or not (problem is, from what I have read, is that the older Kill-A-Watt meters can die on MSQW inverters (hmmm... such is life).

    In the end, if you are going to need a pure sine wave inverter, you can do worst (from what I have read around here) than purchasing a Exeltech Sine Wave inverter of some sort (still cost 10x the price of the cheap MSQ's though).

    Sorry, not a whole lot of extra information that I can provide...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    #3
    Re: MSW inverter and cordless drill battery chargers

    I ran a DR2424E MSW inverter when I just started off grid living, yes it fried my first DW bat charger + a couple of mobile phone chargers and every PIR light fitting and whilst it didnt fry my Compaq laptop it never ever shoowed the battery at 100 % . We learned and managed to charge the mobiles and other items only when my Kipor Inverter based (Honda EU copy) suitcase generator was running. A couple of hundred bucks and change could get you the small Morningstar 300w Sinewave inverter and you can expand your product use the choice is yours See http://cgi.ebay.com/Morningstar-SureSine-300W-Pure-Sine-Wave-Inverter_W0QQitemZ150101101246QQihZ005QQcategoryZ41980QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

    The other cheaper option is a mains drill
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  • landyacht.318
    landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    #4
    Re: MSW inverter and cordless drill battery chargers

    Do the electronic devices that self destruct on a MSW inverter do so by overheating?

    Or is it a case of instant failure?

    My 4 year old laptop will charge fully and run normally on my coleman 800, but the second the battery reaches 100 percent, the computer starts to brainfart. I never noticed more heat than normal from the ac/dc converter. I do notice that when the battery is charged by a wall outlet, it lasts longer than when charged by the msw. Also when bringing up the battery info capacity page , I notice over time that the full charge capacity falls much faster from the design capacity when recharging with the coleman as opposed to grid power.

    Are Nicad batteries succeptible to sulfating when left fully discharged?

    I don't have a scope, and for all I know the coleman 800 is a square wave rather than a modified sine wave inverter.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: MSW inverter and cordless drill battery chargers

    I will take a shot at your questions...

    One cannot tell for sure when and how any particular device will work or fail... The problem is MSQW inverters have very sharp on and off edges (rounded square wave)... Many small (and sometimes cheap) devices use the fact that utility power is a pure sine wave which have relatively soft leading and trailing edges. (the math turns out that square waves are a sum of a bunch of sine waves, each higher in frequency--I forgot it is something like all of the odd harmonics or something like that). When using inductors and capacitors on the front end of electronic devices (and electric motors)--these front ends behave differently at different frequencies... Capacitors tend to pass more current (and over heat the various devices) and inductors tend to block the higher frequencies.

    Electric induction motors (non-brushed motors) are, more or less, a spinning interior field tied to the 50/60 Hz line frequency (which is, in turn, driving their rotational speed by "dragging" the shaft rotor around with the 60 Hz electric field). When you have higher frequencies, these "rotational" fields are not turning with the shaft speed, but faster--and the only place for that excess energy to go is in heat (so these motors tend to overheat easier).

    Transformers also tend to create "eddy currents" from the higher frequency components and this currents are turned into waste heat (in the transformer).

    So, in the end, it is usually heat that causes some devices to fail when exposed to MSQW inverters. The problem is detecting an overheating condition before significant damage is done. Some items you can hold in your had and feel them get too warm, or you may smell something getting hot, etc...

    Over the years, I have had a few MSQW inverters and nothing has ever failed for me (1970's color TV, drills, electric shaver, some specialized meters that required AC to operate, etc.). And I have never really worried much about it before...

    But with the expense and "fragility" of some of these new electronics (computers and expensive audio gear)--I have avoided using MSQW inverters for anything I really care about (or in non-emergency situations).

    I should someday break down and purchase my own sine wave inverter--right now though, I purchased a backup Honda eu2000i generator as my "backup device" (as opposed to running my car battery in an emergency).

    Regarding NiCads... What kills them is constant overcharging (overheat), or discharging them in series where one (or more) cells discharge below 0 volts DC and actually reverse polarity and charge "backwards" (example, 4 fully charged NiCad cells and one 1/2 charged cell--the half charged cell will go to zero volts and reverse while the other 3 cells continue normal discharging). Storing them at Room Temperature and recharging them once per year is probably fine... Check out this neat Battery Storage FAQ for a one place stop to lookup how to store various chemistry/brands of batteries.

    Sulfate is "Lead Sulfate", so technically, sulfating is a term only for Lead Acid batteries and it is when the normal "fluffy/soft" Lead Sulfate that forms (as a battery is normally discharged) is left for day (or several days) before the battery is recharged back to 100% capacity. Lead Sulfate hardens (changes state?) after a day or few, and does not get changed back to Lead as the battery is charged--slowly reducing the overall capacity of the storage battery (hence the recommendations of not leaving a Lead Acid battery sit for months with less than full charge--or at least >80% charge).

    One other warning if your Lead Acid batteries are exposed to freezing temperatures--a fully charged battery will withstand very low temperatures before freezing (and splitting the battery case). A fully discharged one will freeze very near 32F/0C.

    Some Manufacturers of AGM batteries claim not to be affected by hardening sulfates.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • landyacht.318
    landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    #6
    Re: MSW inverter and cordless drill battery chargers

    Thank you BB for the knowledge, and the effort required to type such a detailed response!

    The reasons I ask about the PC battery charger is that soon I will be Boondocking in Baja and will try to complete some woodworking projects in and around my Van.

    Now that I know the most my dc refer will use in a day is 28 amps@ 95 degree plus ambient temps, I actually have an energy surplus, at least on the sunny days.

    I was worried that if I ran my NICads nearly all the way down and didn't recharge them promptly, they would fail prematurely.

    If I absolutely needed to recharge the batteries and didn't feel like driving the 45 minutes to the nearest grid, I'm gonna try it on the MSW. I have one of those laser thermometers and a couple of small 12 volt muffin fans, so if worse comes to worse, I'll try it, ventilate and monitor the charger for too much heat.

    One thing about the PC charger that failed on me while left plugged into grid power, is inside the charger there was a 2 inch brass colored heavy metal cube with 2 wires running to it. I'd opened it up an hour after unplugging it, hoping I could just replace a fuse. This brass cube, after an hour unplugged was still too hot to touch.

    The replacement charger does not have this brass cube 'transformer?' in it. Would this make the new charger more or less succeptable to death from overheating?

    I read something about it being a switched source but that's another thing I'm clueless about.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #7
    Re: MSW inverter and cordless drill battery chargers

    I have no clue what will happen (or not) on a MSQW inverter.

    One problem that you may have is that a fan cannot cool the components enough to prevent failure.

    If you are going to use the MSQW inverter--you might as well try it now at home rather than in Mexico miles from no-where and have something fail.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • landyacht.318
    landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    #8
    Re: MSW inverter and cordless drill battery chargers

    On second thought, I think I'm just gonna buy a harborfreight corded drill. It's cheaper than a true sine wave, and I can keep my PC drill's charger healthy. Since Ni cads don't get destroyed by being left discharged for a little while(thanks for that link), I'm not gonna risk destroying the charger when the nearest true sine wave is a 45 minute drive away.

    Thanks again for the knowledge and effort.
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  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    #9
    Re: MSW inverter and cordless drill battery chargers

    You say that your new cordless charger is a lot lighter than the original model, be warned then as the dewalt chargers are also very light with no standard copper coiled transformer inside if your drill manufacturer has gone the dewalt design route it wont last long, 10/20 hours on MSW :cry:
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  • landyacht.318
    landyacht.318 Solar Expert Posts: 82 ✭✭✭✭
    #10
    Re: MSW inverter and cordless drill battery chargers

    Today my uncle stopped by, and I told him of the topics of this thread. Long story short he gave me a cheap SKIL corded drill, and an old 9.6 volt craftsman cordless drill, battery and charger! The battery seems to take and hold a pretty good charge.

    The 9.6 I can just charge off my 12 volt system as long as I monitor it for overcharging.

    Now I don't have to risk the PC drill's charger.

    Thanks again for the input.
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  • Lefty Wright
    Lefty Wright Solar Expert Posts: 111 ✭✭
    #11
    Re: MSW inverter and cordless drill battery chargers

    When I plugged my DeWalt charger into my MSW inverter it blew up instantly.

    When I opened up the case I found a glass fuse that was soldered in had blown.

    After replacing the fuse the charger worked, but I never again connected it to my msw inverter.
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  • System2
    System2 Posts: 6,290 admin
    #12
    Re: MSW inverter and cordless drill battery chargers

    My several bad experiences with MSW inverters have resulted in failure of the electronic power supply in the item powered by MSW. The failures had occurred in 5 minutes or less, as the components in the power supply continue to overheat to the point of smoke, at which time it's too late. In two cases, the first part to fail was the built in "fuse resistor", which I was able to replace and continue using the item - - but NOT on MSW. With this past experience, I watched for and detected within 1 minute, abnormal warmth coming through the back case of my "Kill A Watt" unit, saving it from destruction. Now it only sees pure sine.
    Wayne
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  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    #13
    Re: MSW inverter and cordless drill battery chargers

    The only thing fried instantly were PIR security lights and switches when I used mine , the dewalt charger didnt pop it went to a flashing led error mode then was the same error mode when back on grid mains or inverter generator
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  • System2
    System2 Posts: 6,290 admin
    #14
    Re: MSW inverter and cordless drill battery chargers

    This is very interesting because about 1 week ago, I called the Dewalt service center in my state and inquired about using MSW inverters for their 18 volt chargers that charge up theri 18 volt power packs. They told me that it should not be a problem as long as the inverter has a rating higher then the watt draw of the dewalt charger. They told me that the problems encountered when people try to do this is that people usually purchase the cheapest inverter they can find that isnt rated high enough in watts to run the chargers, and that is why the problems arise. Buit maybe this Dewalt technician is severly mistaken ? If so, Im a bit upset because after he told me it would work fine, I went and purchased a 2500 watt Cobra modified sine wave inverter. If he told me wrongly, I would have saved my money and purchased a pure sine wave inverter.

    One thing I have noticed in the last several weeks of me researching and calling companys regarding solar power/panels. There is alot of conflicting information being given and many of these so called " companys" are either severely understaffed or they dont care about serving customers and returning phone calls or emails. It looks to me that there is alot of room for improvement in the solar business when it comes to knowledgable staff and customer service. Maybe some of these companies dont want to deal with the " little guys" who only want to spend under $10,000 ? Im quite dissapointed in my expireinces so far when it comes to calling these companies.
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #15
    Re: MSW inverter and cordless drill battery chargers

    They (DeW) may be right. I have used my 2 DeW multi-voltage charger (light weight = no old type transformer) to recharge 14.4 and 18 vXRP batteries with my Vector SST MSW inverter, each time waiting for the puff of smoke and so far nothing.
    Feared the worst for the chargers state when I read the preceding comments but have used them since on inverter, PSW gen set (honda e1000) Brushless 3500w genny (Yardworks) and on mains power and it is working fine (so far).
    Did get a strange fully charged indicator when batt was first placed in cradle once when on MSW but unplugged it and reconnected and it has worked fine (since)

    Cheers
    Eric
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #16
    Re: MSW inverter and cordless drill battery chargers

    anytime you consult a company such as you have sunnyday, the advice given may be of ignorance on the employee's part so to cover yourself you should get a person's name at the very least if you can't get them to put what they say into writing. that way if something goes wrong you have recourse because of bad advice given and the company will take it out on the employee that gave that advice. in the case of a company with bad pr to the public or are shady you could get burned needless to say.
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  • System2
    System2 Posts: 6,290 admin
    #17
    Re: MSW inverter and cordless drill battery chargers

    There are two main problems with using MSW inverters with a most chargers of that type, and in almost all cases it's nothing to do with the inverter being undersized. The chargers are not heavy loads at all. Anything but. A little 200 watt inverter would be more than big enough. 2500 watts is way overkill, but great for sales commission :)
    The first problem is that an MSW inverter has in fact, a modified SQUARE wave output that many sensitive electronic circuits cannot cope with and thus the smoke.
    The second issue is the peak output voltage of an MSW inverter is substantially lower than that of true sine wave power, be it inverter, or grid. The average voltage is roughly the same, but the peak voltage is lower. Thus, depending on the design of the charger, if it doesn't smoke, it may well not produce a high enough voltage to fully charge the battery. Been there, done that. As far as the charger people not understanding this, don't fault them, inverters are way out of their field. In face, many chain stores etc that sell inverters have no one who understands them. It's a specialized field in itself.
    Cheers
    Wayne
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #18
    Re: MSW inverter and cordless drill battery chargers
    landyacht.318 wrote: »

    Are Nicad batteries succeptible to sulfating when left fully discharged?

    Not Quite, they develop nickel whiskers when left discharged, a brief, C x 50 (High current charge pulse, just a couple of seconds long) can burn them out, but at that point, the cell is usually shot, and you are just buying days (not months).
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
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  • System2
    System2 Posts: 6,290 admin
    #19
    Re: MSW inverter and cordless drill battery chargers

    I've "fixed" ni-cads that way in the past, after I "discovered the Cure" in a moment of frustration when I happened to have a 30 amp automotive 12 volt battery charger within reach. Haha In each case, it only took an instant to clear the short. I don't remember how long they lasted after being "fixed". I never understood what was happening, now thanks to you I do :)
    Wayne
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  • t12zh
    t12zh Solar Expert Posts: 62 ✭✭✭✭
    #20
    Re: MSW inverter and cordless drill battery chargers

    I am an R/C guy and have been using All sorts of batterys for several years.
    Information I have for you guys is this.
    DeWalt batterys are what we call A123's ( lot of guys pulling packs apart and using in all sorts of stuff.
    Milwalkee are Made in Canada and we call them E-moli ( There is seven cell's in one battery pack) Note that these cells are 3.7 volt each.
    I use these in a German made R/C heli and charge with a Thunderpower charger that is made for charging what we call lipo's because they are also 3.7 per cell.You could look at this link for more info http://www.rcgroups.com/forums/index.php
    Also as a note these battery packs have charge ballancer built in or lipo's come with a ballancer termanal plug.
    OH there is a lot of DC and or AC chargers out now that we use.
    I hope this is of some interest to you
    Greg
    I think now days the R/C car guys are charging a 6 cell sub c nickle metle pack at arround 4 amps and discharging at up to 30 amps.
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