Davis Instruments specifies using a CR-123 3V Lithium Cell for its Vantage Vue Instrument Cluster.



Because there is a Solar Cell on this Instrument Cluster and there is an implied statement that the Battery is being recharged, the first confusion is that a CR-123 Battery is NOT rechargeable ... CR-123A which is more common is also not Rechargeable ... although these 2 batteries are listed as 3V Cells, common Li Cells range from 3.2, 3.6 and 3.7 volts (second confusion)

When the Davis Station started complaining about low voltage I pulled the battery and found there was actually a rechargeable RCR123A Battery installed in the Cluster. This Battery was a no name brand labeled as 3.0V Li-Ion 500mAh/1.5Wh Rechargeable ... (third confusion is that if Li-Ion has a theoretical nominal voltage of 3.6V why is this battery labeled as 3.0V)

So what is going on here ... is there some configuration of Li-Ion that does actually provide a 3V Nominal Voltage? Or is everyone just over generalizing ... I was going to recharge this battery in a Li-Ion Vista Charger but none of its Li Settings go down to 3V which started me digging for answers

Thoughts?

 

Rechargeable batteries often recharge to an initial voltage higher than the nominal voltage and so the 3.6 volts with only your ten meg DMM as a load will be a lot closer to the 3 volts in actual operating conditions, especially after a few hours. Recharging is always an issue because of the real hazard of overcharging. So it is very wise to measure the charging current so as to avoid damaging the cell. Perhaps ah/15 or ah over 20. A slow charge is safer.

 

Because there is a Solar Cell on this Instrument Cluster and there is an implied statement that the Battery is being recharged, the first confusion is that a CR-123 Battery is NOT rechargeable ...

Or maybe just that while there is light the thing is powered from the solar cell and the battery is not being used and hence will last longer.

 

Or maybe just that while there is light the thing is powered from the solar cell and the battery is not being used and hence will last longer.

That is my guess as well.