# Battery for Moisture Detector

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• posted on April 17, 2016, 5:26 pm
in message I've got a moisture detector that takes a 9v battery, and it says not to use an alkaline battery. Never seen that type of warning before. Anyone know why an alkaline battery is not recommended?
Thanks.
== About the comments about differences in current between battery types. My understanding is that 9V is 9V and the current is determined by the resistance in the circuit.

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• posted on April 17, 2016, 5:47 pm
On Sun, 17 Apr 2016 10:26:07 -0700, "Snuffy \"Hub Cap\" McKinney"

Well, apparently Snuffy will not see my reply unless someone re-posts it - but so be it. The current drawn is dependent on the resistance of the circuit. This is true, but there is resistance in 2 very different and separate parts of the circuit - the source and the load. The "internal resistance" of the battery limits how much current the battery can supply - irrespective of the "current draw" dictated by the load resistance. If the internal resiatance of the battery is too high, the voltage across the load will drop to well below 9 volts in use. The power dissipated across the internal resistance of the battery as heat will compromise the life of the battery, reducing the total net power available from the battery to a fraction of what would be available into a higher resistance, or lower "powered" load.

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• posted on April 18, 2016, 3:50 am

to use an alkaline battery. Never seen that type of warning before. Anyone know why an alkaline battery is not recommended?

types. My understanding is that 9V is 9V and the current is determined by the resistance in the circuit.

Thanks for reposting. I missed it the first time. Would an alkaline battery be more susceptible to developing a high internal resistance than the el cheapo type?