Elu SAB75K Batteries

Discussion in 'Tool Talk' started by doobleshaft, Sep 8, 2013.

  1. doobleshaft

    doobleshaft New Member

    Does anyone have one of these drills and like me have poor batteries?

    None of my Elu 14.4v batteries hold a charge now but I do have two compatible DeWalt batteries, one of which works perfectly.

    I've fixed one of my DeWalt batteries in which one of the solder joints had failed so I can at least use the drill. I can't however figure out how to open the Elu batteries (EZWA 77) to see what the problem is with them.

    With four failed batteries I'd hope to make up two good ones if I can find which cells have failed but sadly the battery packs have no screws in them and I can't work out how to open them.

    Anyone got any ideas how to open the battery pack??

    I could butcher one of them to figure out how but I'd like to keep them all in working condition if possible.
  2. big all

    big all Screwfix Select

    its testament to the elu quality
    batteries only have finite life any thing over 5-10 years is a bonus so 20 years is exceptional even if you get them going again the voltage is likely to be down substantially and you will be on perhaps 15% ah capacity[0.3ah for a 2ah battery]
  3. doobleshaft

    doobleshaft New Member

    For the drill as a whole yes I can agree. Though it makes an odd noise it still works perfecty.

    The voltage won't be down when the cells are replaced which is the point though every other method I've tried has exactly the effect you mention. I can buy compatible battery packs cheap, finding originals which are not likely to be much (if at all) better is difficult but they seem to be over £100 when I do. The claimed originals are probably compatibles that are sold by unscrupulous sellers claiming they are originals.

    I bought a compatible NiMH battery pack for a Hitachi drill which knocks spots off even perfectly working originals. So I was hoping to, as I have done with some other drill packs, just change the cells.

    The current 1.4Ah packs I have now are not charging to full voltage and losing it within hours. But the compatible DeWalt DE9091 (and others including DW9091) work and they can be unscrewed and inspected.

    I've no idea how long these have lasted but the originals certainly look like anything up to 20 years old so not surprising that they have failed.

    So anyone got an idea how to open the pack without using saws, chisels, drills or otherwise butchering? I definitely want to keep this drill as a good example of something made in England that lasts.
  4. big all

    big all Screwfix Select

    i only have dewalt
    surprized they are any different in securing the battery pack together
    can you take a picture off the top and the bottom off the battery pack
    and a picture off any seams tou can identify
  5. doobleshaft

    doobleshaft New Member

    Apart from colouring, branding etc. they look identical until you see there are no screws. Seams from memory were identical but I'll take photos and post.

    I may have to open the DeWalt battery to compare and then see if I can use that to compare with the Elu battery but still looking like first battery will be broken.
  6. big all

    big all Screwfix Select

    if its glued together you will have to carefully cut through the glue with a sharp craft/stanley type knife or an oscillating saw
  7. doobleshaft

    doobleshaft New Member

    There's no way of seeing any glue. It looks like I need to lever the two sections apart and hope there is no glue.

    But I'll post pictures when I get a chance.
  8. big all

    big all Screwfix Select

    are you planning on recelling all the batteries??
    if not cannibalise one off the elu and if you dont get it open easily you can study the broken remains as how to open
    have you looked on utube theres bound to be a video on there
  9. Sean_ork

    Sean_ork Screwfix Select

    chances are the 2 half's of the battery form will have been induction welded, which rather effectively fuses the plastic sections together as one - if they've just spotted it you might have some joy getting into it, if it's been seam welded then the process will be rather destructive - good luck
  10. doobleshaft

    doobleshaft New Member

    Yes planing to recell which is one reason I'd ideally like to keep all of them intact but with 4 dead ones I'm certainly happy to sacrifice one to find out how to do it if there's no choice. I doubt there's anything on Youtube as a Google search shows nothing. But I'll check. eHow is another useful site but not seen anything on there and their entries can be very frustrating and hard to follow.

    I reckon they are induction seam welded. At least my attempts so far at separating the parts has been unsuccessful which backs this theory up.

    I'm considering comparing to the DeWalt batteries I have and drilling holes based on where the screws are to see if that helps but if they are seam welded I can't see it working. Or yet another option is to use a fine cutting tool to open the pack at the base, remove the cells for testing and replacement and then glue back on.
  11. Sean_ork

    Sean_ork Screwfix Select

    a heated scalpel is worth trying, then just hot melt, or epoxy back together
  12. doobleshaft

    doobleshaft New Member

    If I follow the seam that it looks like I found that that may work.

    Pressing in the blue "buttons" at the side I've noticed how thick the plastic at the top is. This has given me maybe a means of removing the top by slicing through the side, ore if I'm lucky a means of levering the top off.

    I'll have to post photos on Wednesday. Macro close up photos will help show what it's like and give everyone a with these batteries a chance to help me and themselves.
  13. doobleshaft

    doobleshaft New Member

    Here's the photos I have attached hopefully to this post.[​IMG]
  14. big all

    big all Screwfix Select

    do you have a table or chop saw ??
    my suggestion would be cut a block off wood and use this to guide a hacksaw
    tennon saw ossilating saw or any other method
    you need to be aware how deep you are cutting if you wish to avoid the batteries
  15. doobleshaft

    doobleshaft New Member

    After being tom and dick for a few weeks now thinking about this again.

    I have one of those Dremmel type things that I'm tempted to use to cut around the battery pack. Not sure where yet but if I treat one as a sacrifice I'll probably cut near the base or on the base itself first.

    Then I'll check how it's fastened at the join between the two sections and see if it is possible to separate the pieces without breaking the pack. If I remember I'll post some photos here so anyone who sees this can do the same to their own.

    That said, it's worth buying one of the many DeWalt compatible packs anyway as they are secured with screws unlike the Elu packs.
  16. big all

    big all Screwfix Select

    batteries decay with age regardless off use or no use so would never concider an old battery when a new one is available
    i have an old dewalt battery i will have a look and see how much clearence you have from vitall components
  17. big all

    big all Screwfix Select

    thinking off it you may or may not come unstuck you would have to cut right at the bottom before it curves round underneath as the batteries are tight to the case in several points
    you also have the metal spring[shaped steel plate] that goes from the base to the seam at the top

    look up dewalt 14.4v ni-mh and you will get a better idea where the actual joint is likely to be
  18. Ray Retired

    Ray Retired Active Member

    Interesting thread Doobleshaft. Never thought about re-celling old battery packs.

    I've half a dozen or so old 18v DearWalts that either refuse to charge or hold a poor charge, been meaning to recycle 'em but will be looking into the possibility of replacing cells, so cheers.

    Just opened one up (hex screws)... Cardboard insulation, really? Cap seems to have a 5mm seat in the base and sits a good 8mm clear of the cells.

    As for opening the Elu packs... I'd go with cutting disc + dremel. 5mm below the top of the base and 5mm deep, epoxy or plastic weld 'em back together maybe. Good luck.
  19. doobleshaft

    doobleshaft New Member

    Thank you Ray Retired. :)

    I had two tired batteries with this drill before I found DeWalt battery packs that were compatible. After looking on eBay I found one reported as dead but was cheap and being DeWalt I could open it. Sure enough it was dead but the cause was a broken connection inside. When I fixed that I had one useable drill at last so it's definitely worth trying.

    One thing I've done is buy a load of dead battery packs as you usually find that not all the cells are dead so you end up with some spares. Plus some of the packs may have use. So with a load that arrived last year I had 3 spare and usable Bosch packs for my ancient but usable 9.6v drill/driver, a few Makita copy 24v packs which worked on my Makita Sitemaster copy (why are there so many of these copied??!), usable Hitachi 18v packs and three more for this Elu drill.

    So I now have something like 5 Elu packs and 2 DeWalt for this drill but only the one DeWalt is usable. NiMH cells seem to be expensive so it's always wise to get the same rated NiCD cells and have them ready. Plus either a spot welder (the best if you can get one small enough) or silver solder, flux paste, new battery tabs (as you are likely to butcher the old ones) and a searingly hot soldering iron. Also wise to have a Dremmel like device with a sanding disc on it to polish up the surfaces before you put the flux paste on.

    Plenty of patience can be needed. I've been trying to solder some connections on a Black & Decker pack for someone for hours and it just will not hold. You can use a conductive glue instead but I'm not completely convinced that this is a good idea for a battery pack.

    One alternative that you can try but I find it's best done only on packs that won't take a charge is to zap the whole pack with a high current source and ideally higher voltage. I did this with a welder at first but had little effect. Now I do it with a variable voltage 8A power source and 12v battery to increase the max voltage to around 36v. It can bring unchargeable batteries back from the dead and at least make them take a charge. Be aware that these packs are likely to take a long time to charge and will get hot during charging.

    Some packs like these Makita Sitemaster copies tend to warp and become unusable if the charge takes too long.
  20. Ray Retired

    Ray Retired Active Member

    Thanks for the comprehensive info Doobleshaft, I'll definitely be trying to revive a few of my corrupt batts, especially given the price of genuine replacements.

    I kinda hate retiring old kit due to battery death, but gotta say the latest DearWalt drills and drivers with the Li-Ion batteries are a pleasure to use over the older and heavier models.

    Just watched a few youtube vids on this subject, seems peeps have varied success rates with 'spiking' using a higher voltage.
    Not sure I'd go so far to zap 'em with me arc welder, maybe give a 3v cell several jolts with 6v for a second tho...

    T'is going to be a project for a winters evening in't shed, I'll disassemble a couple of the corrupt and tired packs, run a trickle charge and test each cell individually, see if I can resource some reputable branded replacement cells for a fair price and go from there.

    Ta much again for the thread and input! :)

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice