Rover8FFR Posted April 30, 2013 Share Posted April 30, 2013 Can anyone help with the batteries for this type of Avometer. Does it use the BLR154 15V cell (Internet search?????) Or other types or can I improvise just for testing.?????? I need a battery to test one that is being offered to me for chicken feed..... I'll post pictures later, but seems genuine and original condition and if it works then it will cost me a couple of bottles of wine to someone via work :wow: Doesn't have the leads or case though, but have those reserved from my favourite FV retailer :cool2: Does come with original cardboard box, manual and original test certificate from AVO. Quote Link to comment Share on other sites More sharing options...
Tony B Posted April 30, 2013 Share Posted April 30, 2013 Avo used to be down by Dover Harbour. Apparently they are now part of the Megger group. http://www.megger.com/ Quote Link to comment Share on other sites More sharing options...
fv1609 Posted April 30, 2013 Share Posted April 30, 2013 Wayne or just don't bother with the 15v battery it only uses that on the high resistance range. For automotive use you will will be measuring around on the low resistance range & that runs off a 1.5v torch cell. It used to be called a U2 but is now called something else. Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted April 30, 2013 Author Share Posted April 30, 2013 Weren't they the square type block type. Any chance of a photo Clive? To compare notes. Quote Link to comment Share on other sites More sharing options...
Rangie Posted April 30, 2013 Share Posted April 30, 2013 The 7 Mk2 uses a 9v 1M resistance circuit and a 1.5v 10K circuit. The batteries are in part to power the circuit but mainly there for biasing purposes. From memory its a pair of the old flat 4.5V torch batteries with the long brass connectors, 1289 rings a bell. We used to solder on a couple of stud connectors and upgrade to a PP7 or PP9, commonly available from the main stores! :-D They used a fair mix of batteries over the years, not to mention the 22.5V cells used in Avo8's and Panclimatics!! Alec. Quote Link to comment Share on other sites More sharing options...
andym Posted April 30, 2013 Share Posted April 30, 2013 Wayne or just don't bother with the 15v battery it only uses that on the high resistance range. For automotive use you will will be measuring around on the low resistance range & that runs off a 1.5v torch cell. It used to be called a U2 but is now called something else. Nice to know that someone else thinks of them as U2s! :-) Andy Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted April 30, 2013 Author Share Posted April 30, 2013 Images of item dated May 1962. Can anyone explain wires. Are these for 1.5v battery Quote Link to comment Share on other sites More sharing options...
Rangie Posted April 30, 2013 Share Posted April 30, 2013 (edited) Images of item dated May 1962. Can anyone explain wires. Are these for 1.5v battery A pair of 4.5V 1289's on the left. On the right, the wire is for the 1.5V cell. It was a common battery in test gear (An R1662), with a positive brass terminal on the middle of the top and a black negative wire poking out the top corner. Take the link wire and use one end of it to connect the +ve to the cell and connect in the -ve black flying lead to the other...... Now, have a hunt around Maplin/RS and find solder-tabbed 1.5V cells (C Cell), and solder flying leads onto it and hey presto, connect it in! When we were still using one (we had a few Avo8 for testing some gear but had one Avo7 and a Multi-Minor for posterity), we couldn't get that little battery latterly so I dissected one!! Inside was effectively mounted a C cell, replace that and off it went for another year until we changed it out of routine.... :-D The maintenance regime was kinda daft, change batteries annually. They were used for reference voltages instead of constant-voltage generators as it was seen as a more rugged and basic solution back in the day. A few milli/microamps were then drawn during the actual resistance test. A battery could last 10 years!!! :shocked: Hence why you should always "Zero" an ohmmeter, it's actually setting the base current for the future measurements, when the battery is flat it won't even have the energy to deflect the needle!! :-D Again, for these reasons you should use Zinc-Carbon Batteries instead of Alkaline ones to get more stable results. Blue Ever-Readys instead of Red ones, remember them?? :cool2: Pictures of the beasties: (found on t'interweb) Alec. Edited April 30, 2013 by Rangie Memory Prolapse!! Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted May 1, 2013 Author Share Posted May 1, 2013 Wow. Alec thats helpful. Thanks. Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted May 1, 2013 Author Share Posted May 1, 2013 Those Lantern Batteries are still available from Maplin, but cant find any C type cells that you can solder a connection too :-( Quote Link to comment Share on other sites More sharing options...
Rangie Posted May 1, 2013 Share Posted May 1, 2013 RS then :-D 1289 Battery 221-204 http://uk.rs-online.com/web/p/speciality-size-batteries/0221204/ C Battery 451-855 http://uk.rs-online.com/web/p/c-batteries/0451855/ C Holder 114-1683 http://uk.rs-online.com/web/p/battery-holders-mounts/1141635/ Worth a go, at 2 pounds its worth a punt to see if it fits the hole.... :cool2: Alkalines though, you don't see may Zinc Carbons these days. For your purposes they'll do no probs. As with all batteries in test gear, DON'T fit and forget, have a peek at them occasionally to make sure they look good. Alec. Quote Link to comment Share on other sites More sharing options...
Rover8FFR Posted May 1, 2013 Author Share Posted May 1, 2013 Alec Thank you for looking this up. RS site seems better than maplin. Regards Quote Link to comment Share on other sites More sharing options...
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