Topic: Davis VP2 Battery life with no sun.

[dahacker]

I've got a situation where I'm trying to decide whether I need to get wired or wireless.

I've go a really small yard and mounting away from the house is not an option.  The easiest mounting for me is going to be about 12 feet out from the house and 10 feet above the walking surface of a deck.  I've got a convenient trellis I'll be able mount a pole on.  Yeah, my wind direction and speed won't be optimal, but I'm not looking for location suggestions, just giving background.

Anyway.  My solar exposure is going to be minimal because its on the North side of the house and most of the day it will be in the house shadow.  How long will the Lithium battery last with minimal solar exposure?  i.e. less than 6 hours/day.  I'll actually have a pretty good shot at the morning sun to the east.

The specs on the VP2 say 8 months with Zero Solar.  Is this correct?  I'll be looking at the 24 hour aspirated version which draws 0.75 Watts.

[Anthony]

I don't own a Davis. But heres my opinion. As for the un exposure, 6 hours is better that none. So if Davis says you can get 8 mons with no sun. Then you shouldn't have a problem. As for the shield. Looking at the pics on the web site. It looks like the shield has it's own solar pannel. So I would assume it has it's own batteries. So I would think you should not have a problem. But lets hear from the experienced Davis owners.

[dahacker]

OK,

So I've read more.  The Lithium battery onboard the VP2 aspirated does not also run the fan.   The fan is run by a separate solar panel and two C Ni-cad batteries.

So is less than 6 hours of sun going to put me negative on the Nicads daily such that they will be drained in a few days?

[FishDude]

I've got a situation where I'm trying to decide whether I need to get wired or wireless.

I've go a really small yard and mounting away from the house is not an option.  The easiest mounting for me is going to be about 12 feet out from the house and 10 feet above the walking surface of a deck.  I've got a convenient trellis I'll be able mount a pole on.  Yeah, my wind direction and speed won't be optimal, but I'm not looking for location suggestions, just giving background.

Anyway.  My solar exposure is going to be minimal because its on the North side of the house and most of the day it will be in the house shadow.  How long will the Lithium battery last with minimal solar exposure?  i.e. less than 6 hours/day.  I'll actually have a pretty good shot at the morning sun to the east.

The specs on the VP2 say 8 months with Zero Solar.  Is this correct?  I'll be looking at the 24 hour aspirated version which draws 0.75 Watts.

I have been running my VP2 wireless (NO FARS) on the same battery now for over a year. I only get a few hours of sun each day. Days are getting much shorter now here in the North East, I have my spare battery ready when needed!

[racenet]

Or just go with the cabled version and forget about batteries all together. 
I haven't changed a battery or had a signal issue, ever. 


Bob

[jmw]

I had my ISS in a similar location when I received my model 6153 as a Christmas gift in 2005.  Until I could get a better site set up, I mounted the unit on my deck which was a northeast exposure for about 6 weeks.    I would only receive about 4 to 5 hours of Sun.   The FARS would run when in direct sun and charge the batteries to run about 6 hours.  This was in the winter when the temps were in the 30’s in the daytime and teens at night.


When I moved the ISS from the above location to the current one, I got called into work and had to leave the ISS in my garage until the next weekend.   I didn’t want the drain the CR-123 so I removed it.  The ISS still transmitted for about 30 hours from my garage in total darkness without the battery.  I think I read someplace that the ISS only needs about 2 hours of sun to keep the unit charged overnight.


JW