How long do P2V/P2V+ transmitter batteries last?

[GRWeldon]

My P2V+ is now just two weeks old. I used the included batteries for the transmitter for about 15 battery charges (say about 4 hours transmitter time). The LED indicator on the transmitter shows green. I believe I've seen it go to yellow in a YouTube video. I swapped my batteries out for fresh ones before the transmitter LED changed colors because I thought it might be a good idea.

When I used to fly RC airplanes in the 90s, Ni-cads were used in the transmitter (and receiver for that matter) and would barely last for 30 minutes before a recharge was required. I will eventually switch to the latest and greatest version on Sanyo's super-duper rechargeables but for the meantime the alkaline batteries are working great.

I was wondering about other's experiences with transmitter batteries for the P2V/P2V+ and about how long they last? Does the LED on the transmitter turn yellow when the batteries need replacing? What happens if you start flying with green and it turns to yellow in-flight? I'd appreciate any useful feedback...

Thanks

 

[HarryT]

When the TX batteries get low, the light flashes and it starts making a beeping noise.

The transmitter uses 100mA at 6V, ie 600mW. A typical alkaline battery is around 2000mAh, so in theory you should get around:

2000 x 4 / 600 = 13.33

hours usage from a set of batteries.

I use 2000mAh NiMH rechargables, and swap them after about 8h of use, to give a decent margin of error.

 

[GRWeldon]

Thank you! That was a very quick and informative reply!

 

[N017RW]

When the TX batteries get low, the light flashes and it starts making a beeping noise.

The transmitter uses 100mA at 6V, ie 600mW. A typical alkaline battery is around 2000mAh, so in theory you should get around:

2000 x 4 / 600 = 13.33

hours usage from a set of batteries.

I use 2000mAh NiMH rechargables, and swap them after about 8h of use, to give a decent margin of error.

Why are converting you Tx drain to mW but not the battery rating? (apples to oranges???)

Also, doesn't series battery connection only add the batt. voltages not their capacity?

I see it as (in a perfect world) with your ratings:

2000 mAh capacity / 100mA amp Tx drain = 20 hrs to the battery's depletion voltage.

However this time should be further reduced by the Tx's internal low voltage threshold of 4-4.3v... No... :?:

 

[HarryT]

Hmmm. I thought my calculation was right, but I can't find any flaw in your logic. Thank you for correcting me - it appears I'm being even more cautious than I thought I was in swapping my Tx batteries after 8h!

 

[N017RW]

Hmmm. I thought my calculation was right, but I can't find any flaw in your logic. Thank you for correcting me - it appears I'm being even more cautious than I thought I was in swapping my Tx batteries after 8h!

OK then, nice to know.

Cheers!