Has anyone ever had issues when using 1.2v batteries for their multitesters ? I've got a KT65DL. and some 1.2v rechargeables - they do work, but I'm wondering whether the lower potential voltage may cause other issues other than the device turning off.
1.2v vs 1.5v batteries for Multi testers
- Thread starter omph
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I've never personally tried, but can't see why there should be much of an issue, particularly when the batteries are newly charged,, given that the testers will work satisfactorily when the voltage of non-rechargeable 1.5Vs has fallen quite a way.
However, if you're starting with say, 7.2V instead of 9V, then presumably the voltage will not have to fall all that far before you reach the point at which it refuses to work, sends 'low battery' warnings etc.
I don't think that MFTs (at least, 'reputable' ones!) will give 'incorrect results' because of low battery voltage - I think they are usually designed not to give any result (or maybe 'switch off') if voltage is inadequate for them to work satisfactorily.
Kind Regards, John
I used to use electret microphones containing an AA cell. I used to have about 100 AA nicad's.
It took me a long time to realise I was forever changing batteries as they 'went flat'. Realistically what was happeningwas the charge voltage of 1.3V or so was fine to run the microphone but when it dropped to the working voltage of 1.2V the microphone ceased to function correctly.
It took me a long time to realise I was forever changing batteries as they 'went flat'. Realistically what was happeningwas the charge voltage of 1.3V or so was fine to run the microphone but when it dropped to the working voltage of 1.2V the microphone ceased to function correctly.
When you say "containing an AA cell", do you literally mean one cell?
If so, then anything containing semiconductor electronics designed to work from a 1.5V battery (which may be 1.3V at end-of-life) is (given semiconductor junction potentials) sailing fairly close to the wind, so the difference between 1.5V and 1.2V could well make the difference between working and not working.
However, if there are, say 6 x AA cells (as many MFTs), then although the percentage difference is exactly the same as with, the absolute difference between 9V and 7.2 volts is much less likely to cause problems (might well still work at, say 5V).
Kind Regards, John
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The main problem is with the use of silicon controlled rectifiers to switch the supply, I know from bitter experience camera flash guns fail due to the much higher current the rechargeable battery can deliver compared with primary cells.
However some equipment designed to use rechargeable cells, I remember having a CB where there were two shorting strips fitted when using primary cells, but these were removed when using secondary cells so the battery contained two more cells.
I likely secondary cells as less likely to leak than primary cells, but depends on how much used, a pair of AA batteries with secondary cells likely even if not used will be depleted after 6 months, where as with primary cells they will last 2 years in my TRV heads, swap every year to be sure, but will run 2 years.
My insulation tester I think 8 x AA cells, after each use they are removed and put in a cardboard box out of the meter, but stored together, in case they leak, did try rechargeable, but the battery warning light came on, so not sure getting full 500 volt once lit.
And it is the same with so many items, they have a battery warning lamp which lights far too early with secondary cells. And with Horstmann wall thermostat it had a warning "Important! Alkaline batteries must be used" and even with Alkaline AAA cells the battery warning light came on after the point where they would not power the relay, and I could only fit in two single cells never found any 1.5 volt batteries, but have found A27 and E23A batteries which are 12 volt, but with a quick glance look like AA cells.
However some equipment designed to use rechargeable cells, I remember having a CB where there were two shorting strips fitted when using primary cells, but these were removed when using secondary cells so the battery contained two more cells.
I likely secondary cells as less likely to leak than primary cells, but depends on how much used, a pair of AA batteries with secondary cells likely even if not used will be depleted after 6 months, where as with primary cells they will last 2 years in my TRV heads, swap every year to be sure, but will run 2 years.
My insulation tester I think 8 x AA cells, after each use they are removed and put in a cardboard box out of the meter, but stored together, in case they leak, did try rechargeable, but the battery warning light came on, so not sure getting full 500 volt once lit.
And it is the same with so many items, they have a battery warning lamp which lights far too early with secondary cells. And with Horstmann wall thermostat it had a warning "Important! Alkaline batteries must be used" and even with Alkaline AAA cells the battery warning light came on after the point where they would not power the relay, and I could only fit in two single cells never found any 1.5 volt batteries, but have found A27 and E23A batteries which are 12 volt, but with a quick glance look like AA cells.
Yes just one cell. To run a FET preamp within the mic capsule.
The current draw is so low these mics will run for years on a decent cell, such as a duracell but a nicad would appear to 'go flat' in a day, certainly by the following weekend. It probably took me a couple of years of battery changing to realise what the problem was. The trouble then was forgetting to check them to avoid leaking.
One of my colleagues used 2 1/2 AA nicad's.
I must confess I've gone right off rechargeables now as the Nimh's just don't have the same life as Nicad's.
That's what I suspected. Given that, as I said, that supply voltage is probably heading towards being 'marginal', even at 1.5V - so, as I said, the difference between 1.5V and 1.2V might well be the difference between working and not working, whereas something deigned to work with 9V would probably work fine at 7.2V (same percentage difference) and, very possibly, at much lower voltages.
Kind Regards, John
Yes I agree with this wholeheartedly. However when using multiple batteries (cells) in a system for higher power devices (for example portable CD player, cameras, radio mics etc) it feels fine to use them for everything on the day.
The best advice is to find what is the end point voltage for the device, ( ie the voltage below which the device will cease to operate correctly )
The endpoint voltage may be included in the technical specification or it may be necessary to ask the manufacturer.
Sometimes the end point voltage is hinted at by comments in the instructions about the type of battery to use.
Case in point.
Last week there was persistent high pitched but barely audible noise in my understairs store cupboard. Seemed to be coming from different directions depending where my head was. Reflecting off walls and boxes After taking everything out of the cupboard the culprit was located,
An abandoned Klippon UT2, probably been in the deep recess of the cupboard for 5 years or more. The 12 volt battery had drained down to 10.8 volts. measured after removal, ( Duracell MN21/23 Alkaline ) so I guess end point voltage for a UT2 is about 10 Volt
We still have a large stock of Avo 8's, ranging from MK2 to Mk7 - finding 15V batteries has become ever more difficult!
A quick google search show multiple sources of BLR121s, eg.
https://www.watchbattery.co.uk/shop/products/BAUV-BLR121.shtml
Lithium disposable batteries keep their voltage very well, and last a long time. The shelf life is incredible.
They are a bit expensive, but very suitable for a low-drain appliance, or a tester infrequently used
Before rechargeables improved so much, I used them in cameras
P.s
After advice on here, I have used a few green solder-in lithium to replace the standby battery in devices with internal timers.
They are a bit expensive, but very suitable for a low-drain appliance, or a tester infrequently used
Before rechargeables improved so much, I used them in cameras
P.s
After advice on here, I have used a few green solder-in lithium to replace the standby battery in devices with internal timers.
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