F2 recheargeable battery question

[luci]

Hi, i would like to addapt my F2(warranty expired) to work on a LIPO recheargeable battery(1500 mah minimum).

I will build 2 dummy 9V batteries and tie them to the LIPO. That way if i run out of LIPO, i can allways use regular alcalines.

My question is what kind of voltage regulator does a F2 have? Can i use 11.1V LIPO batteries or 7.4V ? I have the option of using NiMh 9.6V types, but i would preffer LIPO ( constant voltage output, low discharge for cold weather).

Thanks!

 

[REVIER]

I really have no idea and I am looking forward to some good, logical answers, and I have no evidence to support this, but something tells me it would not be a great idea to go over that 9 volt level of those batteries very much or for very long.

 

[luci]

All detectors have(or should) a voltage regulator that lowers the input voltage to a circuit supported one. The problem appeares when you give it too much power. It fries...
If the power is too low, the detector will not have the necessary voltage to function. So this is what started my question. I want optimum performance without destroying my F2.
I have chosen 1500 MAH because a regular Alkaline is about 540mah. So i will power both dummy batteries in parallel from the LIPO. It should last longer than alkalines

 

[REVIER]

A cool experiment, lets hope for the best.
I buy 8 really decent Ray-O-Vac batteries in packs from my local Batteries plus store for $11.99 and they last a good long time so I am happy about that for now and it seems pretty cost effective.
I have been curious about some rechargeables and I would not do what you are planning, but some F2 owners have had good luck with 9v types.

 

[luci]

This rechargeable is an airsoft rifle battery and costs about 15$, so for me it becomes cost effective after 5-6 paires of 9 volts. Considering the cold weather, i say about 10 detection trips. I change the batteries when the meter says "half battery" (optimum performance).

 

[Dave J.]

The two 9 volt batteries are used differently in the circuit. Therefore what you propose won't work, and may damage machine.

Two independent 7.4 volt Li-ion or NiMH packs would probably work, although a little clumsy. Whatever you do, make sure you don't get them connected backwards.

--Dave J.

 

[luci]

Hi Dave and thanx for the answer. I read somewhere that 1 battery is for audio and one for the coil. I also understand(now) that i need 2 separate batteries.
I think i should not try the 7.4V battery, the purchase price would not be justified for a clumsy detector.
I should use the 9.6 V NiMh then (if the 11.1v is too high). This just ruins my plan to use the armrest pipe as a battery holder
Regards!

 

[Dave J.]

In the "9 volt rectangular" battery style, NiMH come in 7.2, 8.4, and 9.6 voltage ratings. I'm not aware of higher voltages being offered. The F2 will probably work just fine with 7.2 volt units. Going higher than the necessary voltage won't buy you any performance, and the higher voltages will probably have a lower mA-H capacity rating resulting in less battery life.

There are also "9 volt style" lithium rechargables these days, but I don't really know anything about them. If they're rated at over 7.2 volts and are recommended for high-drain applications (for example motorized toys) they'll probably work just fine, but if they're for low drain applications (for example smoke detectors) the F2 probably won't like them.

--Dave J.

 

[djcnTexas]

I have been using some maximalpower 550 mah, 9v li-ion rechargeables in my F2 and F5 for quite some time now and they appear to perform and last about the same as an alkaline. The power meter on the F5 shows 8 volts when fully charged. The copper tops show 9. The only drawback (if you can call it that) is that the covers (not the battery itself) get beat up where they back up to the retaining tabs. I know this is not what you were asking originally, but hope it helps a bit.