Metz 60CT4 power pack setting for NiCad vs Dryfit

Discussion in 'Lighting Equipment' started by BeBu Lamar, Jan 2, 2021.

  1. I have the Metz 60CT-4 with dryfit battery and yesterday I was going to turn it on to form the capacitor and found that the battery cracked and has only about 3V. So it's no good. I can't find anywhere to buy a replacement battery. I can't find any gel lead acid battery with similar electrical specs that would physically fit in the power pack. I know that the NiCad pack has 5 NiCad cells in it and it's relatively assemble a pack that would fit with NiMH cells. There is a setting in the battery compartment for NiCad or Dryfit but I don't know how to set it. Anyone has any idea?
    I power up the unit using a bench power supply set for 6V and 3A current limit. It seems to work OK.
     
  2. Yes! my flash is set like it's in the picture. I believe I have to set to NC position which is the top position. There is a NiCad pack for sale on ebay for $69 (supposed to be NOS) but I doubt that is still good. However, the case has screws so I can open it up and recell but $69 for just the case is kinda stiff. I am thinking just assemble a pack and connect to the battery holder via alligator clips.
     
  3. The dryfit case can be DIY recycled. It's not particularly easy, and a bit messy, but it can be done and costs nothing - except time.

    You need to cut the case apart at the obvious seam at the top. I used a fine-blade junior hacksaw.
    This reveals the lead plates and acid-gel soaked fabric separators. These need to be carefully lifted out and disposed of. I suggest dumping them in a bucket of mild washing soda solution to neutralise any remaining acid.

    You're then left with a plastic case and a top with suitable contacts. A crack in the case shouldn't matter; it's only going to hold 5 C-sized NiMH cells (don't use crappy NiCds).

    The two parts of the case can simply be taped or hot-glued back together after the NiMH cells have been wired up to the top contacts.

    Allow about 2 or 3 hours for the whole tedious job. And take care when sawing the top off the Dryfit casing!
     
    Last edited: Jan 3, 2021
  4. Oh, BTW. Two YN560 speedlights on a bracket will give you just as much flash power and a bit more versatility; if you ever get fed up messing about with prehistoric flash gear.
     
  5. Your lifespan is too short!
    I bought it new in 2002 and that is less than 20 years and no way prehistoric. And I don't use Youngnuo stuff as they don't have A mode only TTL and Manual.
     
  6. Yes, but until quite recently Metz's design formula for their flash circuits originated in the dark ages.

    There are plenty of other 75 watt-second speedlights to choose from that have A mode. Nikon's SB-24, 25, 28, 800, 900 or 910 for example. A used SB-24 could cost less than a Metz battery or SCA cable. And runs off common and cheap AA rechargable cells.
     
  7. Well I bought 5 Sub C 5000mAH cells and solder them together into a pack. They work fine but I have to see how long they hold the charge. NiMH's don't tend to hold the charge as well as the gel lead acid battery.
     
  8. About 2 to 3 months for standard NiMH cells. Over a year for the hybrid 'ready-to-use' types.

    Well worth paying a bit extra for the newer hybrid types.

    I haven't tried it, but I suspect two AA size cells could be paralleled up to double the capacity. That way you could get around 4800 mAH and 6v out of 10 cheap AA cells.

    There should be enough room to squeeze 10 AAs into the old Dryfit battery casing.
     
  9. The voltage curve of a gel cell and NiMH are different. The gel cell will gradually decrease, whereas the NiMH will be flat then drop, like a knee curve.
    That depends on what the capacity of the gel cell is vs. NiMH.
    The next question is, are the NiMH cells REALLY 5000mAH cells? If the actual capacity is 4000 or less, then well, it won't last as long as you think it will.
    I say this because, I have new Tenergy NiMH cells that tested at significantly less than their rated capacity. In fact the two sets of batteries (total over 20) sub-C and AA, NONE tested near their rated capacity.​
     
  10. The rated capacity is measured under specific discharge conditions hidden in the maker's small-print somewhere. Any variation from that will result in a lower measured capacity. Nobody really expects to get the full advertised capacity from a rechargeable cell.

    However, I think Bebu was asking about the shelf-life between charges, rather than the usage time.
     
    Last edited: Jan 24, 2021
  11. Yeah, I figured the mfg was playing games, with rigged capacity numbers at a LOW discharge rate. So I lowered the discharge rate as far down as the tester could go, and I still got LOW results.
    Interestingly, their AA NiCd cells did meet the rated capacity.

    Next step is to get another brand or two of NiMH cells and test them.
    It is just that I bought more than enough AA batteries, so I really don't need any more.
     
  12. The cells I bought are Tenergy so I doubt that they are really 5000mAh but if they are about 3000 or so is OK. The original NiCad pack from Metz is only rated at 2000mAh.
    Joe, I think of using 10 eneloop AA batteries but I am not comfortable using them in parallel. The Eneloop does have excellent shelf life. Actually 10 Eneloop AA have the same capacity as the original Metz NiCad pack. The gel cell is rated at 4000mAh though and it was the reason why I bought my flash with that option instead of NiCad.
     
  13. BeBu,

    I bought a new production Metz branded Dry-Fit battery from B&H a few years ago-maybe 2018ish. It might be worth checking to see if they still have them. IIRC, it was maybe about $70.
     
  14. It's no longer available. Still have the page though.
    Metz 60-38 Dryfit Battery Cell for the 60 Series Flashes

    Otherwise I would get one. $70 is fine. The original battery lasted for 18 years and I never run out of power during a shoot.
     
  15. Unless you really know what you are doing, I would not attempt to solder directly to the ends of the battery.
    I buy the cells with tabs for that kind of stuff. I can safely solder the tabs, without risk of over-heating the cell itself.

    Unfortunately, these ultrasonically welded battery packs are a PITA to deal with.
    You have to be CAREFUL when you cut them open. And REALLY REALLY CAREFUL if it is a Lithium pack.
    Then the fun of "trying" to figure out how to reassemble the pack that you cut open.
     
  16. Darn-I was thrilled that I was able to get one at the time, but I wonder if they were working on old stock or if Metz decided to quit supplying them more recently.

    Out of curiosity, have you tried rehydrating the cells? IIRC, I was able to dig a bit and find rubber caps on my old one that I could pop off to access the cells. I put a few drops of DI water in an old one and milked a bit more life out of it. It still didn't really work, but I got some signs of life out. You could also try a car charger with a desulfate function, or of course if you have a bench PSU I'm sure you can do that yourself(it was one of the things I tried, also with a bench PSU, when I was trying to bring mine back to life).

    Not sure if this would work or not, but the Cyclone type lead acid cells are still available in a couple of different sizes. They are 2V each(just like all LA cells) so you can get away with 3 of them.
     
  17. The case has a crack in it. The battery voltage is down to 3V. I didn't try to charge it. As I said the gel cell doesn't self discharge that much so after I charged it and putting it away and 6 months later I take it out and the flash works fine. This time it doesn't work. The battery voltage is down to 3V and there is a crack and the battery swells a bit also..
     
  18. Gel cells DO self discharge. In your 6 month storage, it may have discharged to just above the level that will still power the flash.

    There is voltage and there is current. The battery could even be at 6v, but not able to generate enough current flow to charge the flash.
    Years ago, I experimented with using a 6v lantern battery for a flash. It did not work. When I put a set of four NiCd batteries on the flash and measured the current, the peak current drain was over 5 amps. The lantern battery was simply not able to push that amount of current.

    If the battery is cracked and swollen, I would consider it dead.
    All you can do is to try to rebuild the battery with new cells.
     
  19. I know when a gel lead acid battery is discharged. The battery should have decent charge left when the open circuit voltage is about 6.6V (by the way it's dead if the voltage is 6V). Lantern battery is very poor in term of delivering high current so even a new lantern battery may no power a flash unit well. The Metz 60 draws only a bit over 3A at peak current draw. You can't rebuild a gel lead acid battery. The NiCad battery pack can be rebuild but a used (probably with bad cells) on ebay is $69 so I pass. I build my own pack with 5 Sub C NiMH cells which work just fine. Besides I solder all different types of batteries without problem. The only thing I worry about is that the shelf life of NiMH is not very good. I would hate it that every time I want to use it I have to charge it first.
     

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