yup, 2 17500 batteries (available from user "AW" on this forum) will work perfectly.
they will work with the bulb already in the 9P, so incase batteries are low you just swap out those for primaries.
for the 6P you have 3 options:
2x 3.0v RCR123 batteries and current bulb (BAD choice, as these batteries aren't meant for high currents like in flashlights)
2x3.7v RCR123 batteries and a 9v bulb (this would be a good choice)
1x3.7v 17670 battery and a 4v bulb (best option overall, mostly because the battery can store slightly more energy then 2 RCR123's would.)
only with the 2x 3v cells can you also use primaries without swapping the bulb first, but be advised, this is NOT a recommendable setup.
also read this:
Avoid 3.0V lithium Ion rechargables
Very often, someone asks a question about using a "special" type of Li-Ion rechargeable battery that is supposedly 3.0V. They usually want to use a pair of these to run their 6V lamps. This is my response to anyone considering this setup...
either:
1. The cells will have protection circuits and won't power up the P60.
2. The cells won't have large enough voltage regulators to handle the current and the will go bad after a few cycles.
3. The P60 will burn out, instantly, or after a few cycles because the Li-Ion 3.0V does not sag under a load as much as the primary cells the lamp was designed for do.
4. The cells will not live up to their capacity rating at the level of power you demand from them, giving poor runtime (10-20 minutes)
5. The voltage regulator in the cell will overheat, in conjunction with the heat from the lamp, and the cell, you will be at high risk of vent-with-flame.
6. You wish you had just started with the 9V configuration to begin with.
choose one of the following configurations:
1. a 3.7V bulb powered by 1 Lithium-Ion Cell.
2. a 9V bulb powered by 2 Lithium-Ion Cells.
3. a 13V bulb powered by 3 Lithium-Ion Cells.
This response is in reference to cells that have voltage regulators built in to step down the voltage.
from this thread:
https://www.candlepowerforums.com/threads/161536
and that thread is a good starting place for anyone interested in rechargeable solutions.
