SHOP PRODUCTS
Houzz Logo Print
jerry_nj

Rapid chargers and NiCad life

jerry_nj
18 years ago

I've been on this forum before to talk about a rather short life Ryobi 14.4V tool NiCads have given me. Now I am finding my 18V NiCads that came with my Homelite garden tools are starting to fail: they take a charge okay, it seems, and if I use them immediately they seem to have an exceptable capacity. But, if I let them sit even over night, the capacity is gone, suggesting a high internal leakage current. When I compare my experience with these batteries with older NiCads that have been charged on the cheap over-night chargers, I conclude either the new higher voltage batteries are not as durable or the rapid charger (1 hour or so) is killing them. I did check one charger and did confirm that the charging current drops to near zero when the charged light comes on. I measured the input current on the 115VAC side of the charger. It was running at about 300MA when the charging light was on, or no more than 35 watts input power.

Comments (29)

  • castoff
    18 years ago
    last modified: 9 years ago

    Uhhhhh. Is there a question to be answered or are you just as pissed as the rest of us over the battery situation in general? lol

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Oh, I am not alone?

    My experience with NiCads over the years has been they are hold up well for a few years of light use. That history came for the days when all battery chargers were stupid, so they were low current, and took many hours to charge a discharged batter. The good news was those charges seemed to give longer battery life, if my current experience is typical: use of rapid charges and the battery may last for 30 tto 50 charging cycles, not 100s.

  • Related Discussions

    Rebuild Cordless Drill Batteries - Scam ?

    Q

    Comments (35)
    It's great to follow this thread, from skepticism to acceptance of rebuilding batteries. I live in Japan but by coincidence all of my battery tools are US brands, and the shipping for replacement Ni-Cd packs is really steep, not to mention the price. After some research I ordered some sub-C cells from an eBay supplier called thundercells and managed to cobble them into the case for my 18-volt WORX hedge trimmer. The cells had tabs on them, which made soldering fairly easy, but it was still tricky (and be careful of short circuits while working because the cells are partly charged. The rub came because I substituted 2500 maH cells for the original 1300 maH, hoping for longer working time. i found that if I left the pack in the charger until the green light came on, it was only partly charged. Big worry! Then I discovered if I put it back in after a few seconds, the red light came back and it went through another charging cycle. If I repeat this 3 or 4 times, it becomes fully charged. Now I am happy again! I get way more full-power cutting time than with the old cells. Total cost was $23 for the cells including shipping from China, and I'll say 4 hours repair time. This seems to make the reputable rebuilding services a pretty good deal, and if I were in the US I'd use them. However there's another set of cells coming, for my trusty 9.6 volt drill.
    ...See More

    Lithium Ion Drills vs Ni-Cad

    Q

    Comments (13)
    I'm hearing from good sources that li-ion technology, even as popular as it is, is very young and is an intermediate step and still evolving with some current problems, like not running in very cold/not charging either, stopping for no reason...then recharging back to full capacity is a couple of minutes, etc. What I hear is the better technology today and for the future is the Li-Nano power tools (Li-nanophosphate), but the only ones that have it in the US right now is DeWalt and Black&Decker VPX. To quote the writer, "14.4 Nano impact is the most lightweight, reliable, powerful and long-lasting driver in the world." Google it for references if you must.
    ...See More

    How I save $50 per year on batteries

    Q

    Comments (5)
    I have similar issues with the rechargables. I like the NiCds but the NiMHs are even better. Also, some of my NiCd's didn't fit in my mini Maglite. It appears the label material was too thick or something. I have been using rechargables since 1987 when I went off to college. I needed a walkman to pass the time as I walked to each class. Also, get a charger that will turn off when the batteries are full. Overcharging batteries will damage them and reduce their life. I usually got 4-5 years from each battery, most people will only get 3-4 years from them. NiCds are the ones that need to be discharged all the way before recharging. The other ones don't (like NiMH, Lithium). Also, most rechargables are only 1.2volts each, while alkalines are 1.5v each. That's why some devices say "Use only alkaline batteries." The device was made for 4.5v (3 x 1.5v alkaline batteries) not 3.6v (3 x 1.2v rechargables).
    ...See More

    Craftsman C3 19.2-Volt Lithium-Ion 3/8-in. Drill/Driver Kit

    Q

    Comments (3)
    On the lithium battery units, I highly recommend the Milwaukee M18. I have lots of stuff and would not go back to a NiCad. If you are an occasional user, you want to avoid keeping them in the charger forever. I think it best to keep them somewhat discharged. You have to watch what batteries that you get with whatever you buy as there are 1.5, 2, 3, 4 , 5 and I think even bigger AHs are available or soon will be. The plus is that the batteries all have the fuel gauge on them. Before you walk across the lawn to use the tool, press the button and your battery life is clearly shown. Home Depot has quite a few and they typically have good buys this time of year. You can buy "refurbished" quite easily to keep the price down too and the tools that I've seen have never been used. I know my time w/ Habitat it was tough to get a battery that had more than 20 minutes run time left in it. :)
    ...See More
  • Baja_Buoy
    18 years ago
    last modified: 9 years ago

    I have DeWalt 18V tools (3 drills, 1 recip, 1 circ saw, 1 right angle) and the oldest DeWalt 18V batteries (5 yrs plus of reasonably careful use) seem to still work fine. They will self-discharge off of the charger but nothing excessive unless they sit for a long while. I have a Milwaukee 19.2V drill that is really great but its batteries took a major dump after 2 yrs of careful use. Consumer Reports ought to test & publish battery life results and include same as part of their ratings. I bet the mfg would then sort their battery problems out pretty quickly.

  • hippy
    18 years ago
    last modified: 9 years ago

    Most likey it is your treatment of the batteries.
    I to have many DeWalt 18V power tools and batteries.

    You must first fully charge the batteries. When using a one hour charger, After they have been quick charged and used 8 to 10 times. They must remain on the charger for at least 10 hours.

    If you have a DeWalt 1 hour charger. It will balance each battery in a pack and charge them at the same time if the batteries are left on the charger over night. It is a built in feature of DeWalt's one hour chargers.

    Ryobi = Cheap.
    Cheap = You get what you pay for.

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Yes, the DeWalt and Milwaulkee should be better, the price demands it. I did notice at Home Depot when I purchased a new Ryobi 14.4V batter at about $24 the DeWalt and, I think, Milwaulkee were over $50. I did a lift test and it felt to me that the more expensive batteries were heavier. So, they should last at least twice a long to get the same time/$. That said, I have other low cost units that have performed much better, including a 12V Sears (lower end of the price range) that still has very good batteries. These batteries have always been charged on the low over-night charger. I even have a 9.6 V I purchased from Harbour Freight for next to nothing and those batteries are performing better than the Ryobi and the Homelite batteries, both of which have lived with a rapid charger (smart) charger. As for periodic over night charging, I can say I've measured the input current on the rapid charger and it drops to zero (best I can read and I can read 0.1 amps), so my conclusion is the Ryobi charger shuts down after the rapid charge. The charge light does remain on, so it is drawing some power, but next to nothing going to the battery. This may well not be the case with DeWalt, I have never owned one, nor a BMW.

  • davidandkasie
    18 years ago
    last modified: 9 years ago

    most rapid chargers only charge to 85-90% capacity before they switch to trickle mode.

    the best thing you can do for a Nicad is to initially charge it overnight even in a rapid charger. when you use it, always allow it to run down before placing it back in the charger. if you use it to drill one hole and then stick it back in the charger to top it off, you are just killing the battery.

    also, never leave a battery in the charger all the time. charge one up when you know you will need it, and allow an extra hour or 2 for the trickle charge to bring the battery up to full capacity. your batteries will last much longer this way.

  • Don_
    18 years ago
    last modified: 9 years ago

    Modern day chargers turn off when the battery is charged. There is no need to remove the battery from the charger. Do it if it makes you feel better.

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    David,
    I think I have overpracticed the "run-um-dead" before recharging theory. One can go too far with that and I think I did on the 14.4V batteries. I have a 14.4V hand lamp which is easily used to run the batteries to the bottom. I did this a few times and I think rather that prevent loss of capacity due to the "memory" problem, it distroyed the cells. I didn't do this on the 18V batteries, and while they will not hold a charge, they will take a charge.

    Don,
    As you say and I noted, monitoring the input on my rapid charger indicated that the charger sut off when the battery was charged. I was measuring the input current (115VAC side) and had a meter that would easily read 0.1 amps and it didn't show any current. Again, I suspect there may have been 0.001 or similar because the LED charged light was on, then too that may have been driven from the charged battery.

  • Baja_Buoy
    18 years ago
    last modified: 9 years ago

    ..... that NiCad can reverse its polarity and then the fun begins....

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Yes, if one reads a no-load terminal voltage on a 12 cell battery, e.g., 14.4V battery and they get much below 12 volts, it is likely that one or more cells have reversed polarity. I think it is possible to "kick" them back to the right polarity, but it isn't a good thing. One problem is the smart chargers are programed not to recharge if the terminal voltage is too low. I say this without any specific knowledge on the charger design, but I can say on a battery with very low terminal voltage, the charge will not switch into the charging state. If I then take that battery and give it a charge from a DC source to raise the terminal voltage, the smart charger will accept the battery and try to charge it. That doesn't mean you've won, the battery may still not take a full charge, or maybe will just not hold a charge for more than a hour or so.

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    I thought I'd resurrect this one to give an early report on my complaint about NiCad quality. Home Depot did "write" back saying they'd take my input of poor batter life into their process of dealing with suppliers. I guess I couldn't ask for more, but would have accepted it :-) In the total, I'd be happy if Ryobi and Homelite got a complaint from a big customer.

    I can also report after the replacement 14.4V batteries I purchased at HD (at $24 each) seem to be better. They are marked "higher capacity" but the marking is silent on the amphour capacity. I have used one regularly in a hand lamp for a couple of weeks and it is still shinning bright, seem there indeed may be an improvement in capacity.

    I will be very careful not to do down to zero discharges on the batteries and will not know for several years, I hope, how well they hold up. So this is my last report on this subject unless I get a real early failure.

  • goldenrule5
    18 years ago
    last modified: 9 years ago

    i have the same set up as jerry, and have had the same problem for the last 6 months, both of the batteries that came with the homelite set will take a charge now and if you use them righaway they do a decent job, but will not hold the chage overnite. i have always done what the manufacturer tell you to do, like making sure they are discharged before you put them in the charger. it is hard to believe that after all these years they have yet to come up with a ni-cad battery that is worth the money they want for it. the set i bought had the hedger/trimmer and the weed wacker plus the charger and the two batteries and home depot had them on clearance for $50 about four years ago. now i think just one of the batteries run about $25/30 which i do not intent to buy.
    my theory is that is all a big scam, like when gillete has the coupon for the free razor and then charges you a fortune for the blades when you go to buy them.

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    goldenrule5

    As I have said, I have had good performance, still receiving, from NiCad batteries that were/are charged using the slow charge method. The Homelite set you have is the same as the one I have, also purchased at HD on sale a few years ago, it is 18V. I figured with two batteries it would last for ten years, not so. I did not get heavy use, I have a gasoline string trimmer for big jobs, used the electric just for touch-up next to the house.

    My concern is: do the rapid (1 hour or so) chargers kill the battery they are charging. My experience suggest this is the case, but as I said I'm giving the 14.4V another chance with the purchase of two new batteries, at about $50 total. I like the drill, circular saw and hand lamp that use the 14.4V batteries, so I am trying again. I do no think I'll buy new 18V batteries.

  • obio3
    18 years ago
    last modified: 9 years ago

    NIMH batteries is a great way to go provided you have a god hot soldering iron/gun that will solder the batteries together real fast so as not to ruin them > i use a short piece of stranded wire between connections > I use the NIMH 2500's for as much power and life as possible > used the appropriate physical sized batteries and connect them to provide the proper voltage > works well for me > I do this or use these with everything including flashlights > last for ever and rechargable

  • obio3
    18 years ago
    last modified: 9 years ago

    OH >>>>>>>>BE SURE TO WEAR GOGGLES JUST INCASE ALTHOUGH I HAVE NEVER HASD A PROBLEM

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Construct your own replacement out of off-the-shelf NiMH cells, seems like a probematic approach. How do you deal with the proprietary electical and physical interfacew to the unit you need to power? and then, how do you package them, just tape them to gether and hang they from the tool? Sorry, I just don't "get it".

    I note too that a 14.4 Volt replacement requires 12 cells to construct. Now if one uses AA batteries, I do see those now a days in the 2000 mah and up capacity, the 12 cell package would be a reasonable size, and would cost about $25.00 for the batteries. I purchased a new Ryobi 14.4V, albeit only a NiCad, for a little less than $25. Again, I don't get it.

    Thanks,

  • obio3
    18 years ago
    last modified: 9 years ago

    If you shop a bit you will save bucks > Real point is better power and longer life between chages > Also I disasemble the factory batery pack and install mine in same > Having a little voltage diferance hurts nothing Infack some companies sujest you pull the triger and run drill or what ever till completely dead > Then change > Having cheaper batteries is not a reason to do this > Better performance is > I know this isn't everybodies dream of a lifetime but I injoy inproving performance >

  • obio3
    18 years ago
    last modified: 9 years ago

    Please don't mind my spelling here > i'm in severe pain again and difficult to see > ty

  • dave_danger
    18 years ago
    last modified: 9 years ago

    I read through all the posts and saw several mentions of things I've tried. One thing to mention first is to make sure exactly what type battery pack you actually have. NiCad's have been around for a long time now and everyone tends to assume a rechargable battery pack is a NiCad. No longer true. There are NiMh (Nickel-metal Hydride)and LiSo2's (Lithium Sodium) as well. They each have different memory charge effects.
    I have used Makita cordless tools for years as an aircraft mechanic. I developed early on the habit of using multiple battery packs. As soon as a tool shows signs of slowing down, I'd pull it out and slip it into a flashlight to kill it dead. I'd then install a fresh battery pack into my tool and keep going. After the run-down battery was completely dead, I'd immediately place it in a charger and bring it back up. At the end of it's charge cycle (those days were no 1-hour chargers), I'd set it aside until I needed it again for a fresh swap. I still have about a dozen Makita NiCad 7.2 & 9.6v batteries, that while no longer having their original snap, still function well. They are anywhere from 4 to 9 years old.
    NiCad batteries are the worst to develop a "charge memory". In other words, if you always immediately recharge the battery when it first shows signs of weakness, you are "teaching" it to only recharge partially. Soon, a partial charge or capacity is all it is capable of holding. You end up with a battery that loses its charge quickly.
    NiMh batteries supposedly do not have this memory effect, but the few batteries I have in this design,(18v DeWalts) are new enough that I have no experience with their longevity. I have determined to my regret that the DeWalt 18v NiMh's do not like being left on a charger past its end of charge. I have 3 ruined battery packs that are not even 2 years old that will no longer hold a charge long enough to turn on a flashlight. That does depend on the charger apparently. I have several chargers, and some of them do turn off the charge current when the charge is complete. My older chargers do not. I have not seen yet whether or not my "kill it with a flashlight" method does anything for the NiMh batteries.
    The LiSo2 batteries are being phased out already for Lithium Ion batteries which have better characteristics. The LiSo2 batteries are known for holding charge and operating over an extremely wide temperature range. This is useful in some industrial applications, not so much in everyday tool use. They were designed originally as a long term storage battery for items like the emergency transmitter radios used in aircraft that send out a broadcast when an aircraft impacts the ground in a crash. Turns out that LiSo2 batteries tend to explode when immersed in salt water (not a good thing for aircraft flights over oceans). They are still used extensively I believe in AED's (defibrillators).
    Going back to the NiCad's for a minute, they do have the ability to reverse polarity, but thery have to be left in a discharged state (With NOTHING connected) for a period of time for that to happen. If it's in a flashlight, it won't happen, if it is intentionally strapped off (shorted from positive to negative) while discharged, it won't happen. This is the way we store NiCad aircraft batteries indefinitely... discharge them to zero volts, then short the negative post to the positive with a metal strip of stainless steel. The tendency to reverse polarity happens when the battery is left with NO charge at all on it, and nothing to keep it at zero. If it is discharged fully and immediately recharged, it's nearly impossible to reverse polarity.
    I've probably bored ya'll to death with this.. I'll go now :)

  • obio3
    18 years ago
    last modified: 9 years ago

    Great post Dave and right on he money

  • Baja_Buoy
    18 years ago
    last modified: 9 years ago

    Dave D
    I leave my DeWalt 18V batteries waiting in a DeWalt (1 hour ?) auto charger from time to time when I am wanting to be sure I have a fresh backup pack for an ongoing project. No apparent problems with battery service life yet, but if the charger were also unplugged from the AC there might be a problem. I had a Milwaukee 19.2V pack killed by an unplugged charger- at least it seemed that way. But then that pack's brother simply died in the drill....

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Interesting, the "run-um-dead" using the hand lamp was my approach too for the 14.4V batteries that started this post.Given the short life I got out of two batteries I speculated two possible problem: the rapid chargers may be hard on NiCad batteries, and to taking the batteries to a very low terminal voltage damages the batteries. Some research on the web did produce some information/views that taking a NiCad all the way down may damage cells, even cause some to reverse.

    I have decided to run NiCads down once a month, or thereabouts, and recharge long before they are gone as a normal practice. As for the effect of the rapid rechargers, don't know what else to use.

  • rkcr123
    18 years ago
    last modified: 9 years ago

    I've always killed nicads absolutely dead -- with a flashlight -- before most recharges. i've also left them on (sloooow) chargers for months when they weren't in use. I have some I bought in 1980 that still work well. Of course I've thrown about as many away, too.

    Biggest problem I've found is internal shorts, usually after a few years of use.

    Cells that are allowed to get hot frequently seem to fail quicker, but I don't know the mechanism or chemistry.

    I use a short-buster made from a couple of capacitors and some diodes (it charges off house current) to zap shorted cells. It clears a bad short maybe a third of the time. I think bigger capacitors would do better but I don't know at what point the cases might split.
    I've had two cells, I think, of maybe 100 reverse polarity. don't know why, couldn't fix 'em.

    I've replaced cells in packs but it's a pain without the appropriate equipment.

    The memory effect thing is one of the most fascinating issues I'm aware of. The popular press (a member of which pays my pitiful salary) turned early sketchy reports into a really scary sure thing -- scared me enough to cause the behavior i described above. But the current thinking that seems most believable to me is that it takes repeated partial discharges to create a charge memory, and the loss is usually only about 10 percent. Three full-charge, full-discharge cycles supposedly eliminate that. Of course there may be a new and different scientific finding at any time. Or maybe not -- nicads are being replaced as Dave Danger says so maybe the issue will finally go away.

    Don't worry: Writers of popular press articles will perpetuate lots of other questionable information.

  • genesii
    18 years ago
    last modified: 9 years ago

    I did not read all of the posts, but with Ryobi rechargables, do not kill them, run them low and recharge.

    DO NOT leave them in the charger, they are better off with a low charge or no charge than being in the charging unit.

    Charge before use, especially if you do not use them all winter.

    This is from Ryobi

  • jerry_nj
    Original Author
    18 years ago
    last modified: 9 years ago

    Interesting on not leaving batteries in the charger. I have monitored the input current to the charger with a meter that read 2 amps full scale, that is it will clear indicate something as low as 0.1 Amp. When charging a 14.4V battery the charger starts at about a half amp (50Watts or so input) and drops to an apparent zero when the charged lamp comes on. Thus I'd assume there is no charging going on when the battery is sitting in the charger fully charged. I'm not arguing with Ryobi about their product. I have read elsewhere and now see Ryobi's recommendation, I will continue NOT running my replacement batteries down to ZERO, I'll use them until the tool light shows lower performance, but not until the light goes out. Then I'll charge. It has been my habit to remove the batteries when they are charged, but I do forget from time to time.

  • poordirtfarmer
    17 years ago
    last modified: 9 years ago

    I've just found this site and suspect that no one is monitoring this year-old thread, but here goes:

    I've always tried to unplug my Makita charger after it has been charging overnight, but twice now I've accidentally left an expensive Makita battery charge for maybe months. The first time it appeared to ruin my first battery and the second time it appeared to ruin the second battery. In both cases the battery was okay and only partially discharged before the very long charge. In both cases the battery was dead as a doornail after the charge. Can anything be done? I found a site that sells a "Makita Battery Resurrection" for $12.95. Is this a gimmick?

  • allen058
    17 years ago
    last modified: 9 years ago

    Hi All - Does anyone know how to repair a dead Ryobi 12V charger? The number is 1411141. Thanks.

  • machiem
    17 years ago
    last modified: 9 years ago

    I'd find one on Ebay rather than attempt to fix one.

    I just looked and you can get a brand new one for less than $20 including shipping.

  • pinecreeknit
    17 years ago
    last modified: 9 years ago

    Buying a new Ryobi 12V charger (1411141).

    How do you test for bad battery? 3 ohm test through battery terminals indicates .010-.013 on one battery and 0 on other battery. Supplier says bad battery will ruin new battery charger.