Having used an Alkaline battery in the Uni-Probe PI for a while as phones with a probe there was no need for experimenting with different batteries as the phones alone don't need battery power.
Obtaining the 12" coil for the Uni-Probe changed the reason for a little try/see testing.
Alkaline worked as they always do, start with full power and performance then slowly the power diminish and so do the performance of the detector the visual way would be to have the battery in a flash light and see the light start of bright then gradually fade to a glow.
I've used 8.25 volt rechargeable NiMh batteries for years in other detectors eider single or in series, even series/paralleled depending on what detector.
Li-Ion 8.25 volt batteries became available and with their higher capacity than NiMh batteries it was just a matter of giving them a try, they have worked very well so far in equipment with regulated power supply.
Out of curiosity I obtained some new 9.6 volt NiMh batteries and tested one in the Uni-Probe PI with the 12" coil, "Sensational" NO but it did make a difference in stability and depth compared to alkaline batteries that is half used and a touch better than the Li-Ion batteries, but the capacity is less so a little calculation is needed before heading out with just one (set) battery.
I would like to compare a HH-PI to the Uni-Probe PI, but I do not have the HH-PI however I guess/expect the HH-PI might have more "oomph' in that it run on 18 volt.
Pictured is the m/amp delivered by each battery using same settings and the 12" coil resting on the ground the voltage was measured without load.
All batteries was used slightly prior to this test except the Duracell which was straight out of the packed the Energizers is used and out of my Pistol Probe.
Hopefully this will not start a war of what battery is best, it's merely an observation from simple testing I shall use the result in selecting a battery for future outings with my Uni-Probe PI.
ivanll
