Products > Test Equipment
Battery options for test meters (Brymen)
<< < (5/6) > >>
AVGresponding:

--- Quote from: wraper on November 09, 2022, 08:58:20 am ---LSD NiMH like eneloop or IKEA LADDA. If there is battery level indicator, you may not get full level indication on freshly charged batteries but otherwise there are no problems in 99% of equipment. Yes they start at lower voltage than alkalines but have much flatter discharge curve and are considered empty at about the same voltage. Ni-Zn are unreliable, have high self discharge and may damage some equipment due to too high voltage. Do not forget that 1.2V for NiMH and 1,6V for NiZn is nominal voltage, not fully charged voltage which is significantly higher. While 1.5V is a nominal voltage of a fresh alkaline (may be up to 1.55-1.6V).

--- End quote ---


--- Quote from: monkey_magic on November 09, 2022, 01:26:51 pm ---Well it is good to know it is not just me that worries about such things!
Thanks for all the replies.

For those using Lithium Energizers, have you encountered any of these supposed issues of cells suddenly dying?
I've seen the rumour on several forums now, so I'm unsure if there is anything to it. For me they work out about the same price as the eneloops, so pretty pricey option for a disposable cell, especially if you don't actually get to use it.

Showing my ignorance here, but I'd never heard of Ni-Zn - sounds like they could have been the ideal solution, but on further research it does seem like they can be quite fragile.

I believe the IKEA LADDA are either the Eneloop Pro or Lite - for me they work out the same price as the original white eneloops, so I just buy them instead.

The 2.5 and 2.85v figures are taken from the Brymen spec sheet. I haven't tested the threshold at which the low battery warning comes on, so I have just assumed the figure they quoted is correct.
However, the 257s didn't show any low battery running on two eneloop cells @ ~1.28V so that may be the best option for it.
The 079 did show low battery warning with Capacitance and Frequency modes on the same eneloop cells, so I assume it does actually need >2.85V


--- End quote ---

I use Ni-Zn in my Fluke 289 with no problems. Fresh primaries can be as high as 1.65V/cell open circuit, Ni-Zn as high as 1.85V/cell. With a multimeter like the 289 which has a constant drain to maintain the RTC, this probably drops off quite quickly, other meters may vary. Been using them in it for over a year, had to charge them twice, no failures so far.

I would say, first try Ni-MH LSD, and if you get low battery warnings far too soon, try Ni-Zn. It's not a massive investment to buy two or three. I use Turnigy brand, as ever, other brands are available. The main inconvenience for me is the dearth of chargers for this chemistry; I just use a bench psu but ofc this might not be available to everyone.
IanB:

--- Quote from: monkey_magic on November 08, 2022, 11:41:05 pm ---I've seen at least one recommendation for using zinc-carbon, but I was under the impression they were just as-leaky as alkaline, especially given their construction.
--- End quote ---

I think modern zinc chloride cells are less likely to leak. Reasons:
- they have a very dry internal formulation
- they do not generate internal pressure
- they have a sealed steel shell on the outside
- I have samples of ZnCl cells that are over 20 years old which still work and have not leaked

The main downside of zinc chloride is the much lower capacity, so they are only suitable for low drain devices.
IanB:

--- Quote from: SkyMaster on November 09, 2022, 12:12:08 am ---You are not paranoid. I am personally extremely fed up of finding leaking Energizer and Duracell alkaline batteries in my devices.
--- End quote ---

Indeed.

I just recently pulled a Duracell from a valuable item that was just starting to leak. It was still at 1.3 V and working fine. Apparently I caught it just in time.
BillyO:
I tried lithium AAA batteries in my BM786.

A full set of fresh alkalines measures at 4.85V and a full set of fresh lithiums measures at 5.4V.  That's only 11% more so I went ahead a tried them  No complaints from the meter.  That will be my solution going forward

I also investigated and found a reversible mod that can easily be done to the battery holder for anyone that is leery about using the lithiums due to voltage concerns.  It involves adding a small diode (1N60 will drop the voltage about .3V or a 1N4148 would drop it about .65V) and can be undone as easily as it can be done.  There is a thin plastic label/sheet onto the bottom of the battery holder.  Removing this reveals connection running from one side to the other.  It incorporates two of the battery contacts and is easily removed.  Solder to the middle section of this the diode (in the correct orientation of course) then cut maybe 1mm out of it between where the diode leads attach.  The replace it into the holder.  Reversal is just as simple.  Remove the contact assembly, solder a short wire across the gap, then remove the diode and reassemble.
BillyO:

--- Quote from: AVGresponding on November 09, 2022, 06:14:58 am ---Ni-Zn rechargeable.

--- End quote ---
These are not only expensive but the voltage on them when fully charged is the same or higher than the Energizer litiums.   Plus, they have a fairly high self-discharge rate so if you are not using your meter often they can be useless when you do and require a re-charge before proceeding.  Add to that if they get too low for too long you can throw them out.

Nice thing about lithiums is the 20 year shelf life.  Even if you don't use your meter for a year or 2 it will likely still work fine.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod