Double Solar panel charging / VP2

[MEnJ_DK]

Hi,
I'm using a Wireless VP2 in Denmark and right now the sun-angle (NSA) are about 10º (that is, if we see the sun at all !)

I have a spare ISS cover with two solar panels, a left-over from a DFARS, and I would like double the charge capacity by using this cover instead.

Question:
Do I connect the solar panels in serie or parallel? - I do understand the difference, but how is the charge circuit designed in the ISS, - do I gain most charge capacity by increase the voltage or the current?

/Morten

[Bushman]

Increasing the voltage is probably not a good idea.  Depending on how the circuit is designed an extra solar panel may not do any good since the current to the supercap is likely regulated.

[dalecoy]

Increasing the voltage is probably not a good idea. 

I agree with Bushman - connect the panels in parallel.  At your latitude, this should effectively double the charge that gets to the supercap.  More current is what you want.

[johnd]

TBH I don't think it's necessary at all. The lithium battery still lasts 18-24 months at latitudes of 50-60N. Are you really that bothered to make it last longer? Possibly the summer months of  getting on 18 hours sunshine at least partially compensate for the 6-7 hours of winter sun.

[PaulMy]

Are you really that bothered to make it last longer?

After 3.5 years on original battery, with everything still working perfect, I decided it was time to replace the battery in the ISS now rather than having to do it later when possibly covered in snow.  We get a fair amount of sun in the summer but many dull, snowy days in the winter yet battery has been good thus far.  Davis says not to expect the same life on the replacement.
Paul

[Bushman]

On what basis would Davis make that claim?  Lost efficiency of the solar panel.  Or something failing?

[PaulMy]

Yes, that is what the customer service rep said, over time will be reduced life!

Paul