Renogy solar?

KJINTF wrote:
Sorry off topic - however my curiosity is killing me

BLF - a question for you
When you go camping in the Provincial Parks - are you on the Pacific coast or inland on the island? I was thinking of exploring Strathcona Park and then on up to SE Alaska

Your beautiful city sure has grown in the past 35 years wow almost did not recognize it - The Butchart Gardens were familiar just several new tourist shops

We prefer the East side of the Island ourselves, but have also been to some of the parks on the Mainland. Each park has its fan club.
We only camp in the provincial parks in the "off season" The rv.net forum for Canada Alaska will get you lots of good tips on any particular campground, park, and routes. Lots of good camping whichever way you go. :)

RJsfishin wrote:
BLF, thanks for your comments.
I have all the specs on the panels, even tho they don't mean much to me.
But I remembered the IMP specs at 5,12a on the 90 watt, and 5.35a on the 100 watt. Add them together for a total of 10.47. Seldom if ever do I buy anything that isn't exaagerated a bunch, so seeing 10.4 output, I was delighted. And that was w/ 2 near full charged batteries, w/ only a bunch of lites on to get the 10 amp output. Not long after turning everything off, the controller would start into float mode w/ only a couple amps output.

ISC 6,15 & 5.72
VMP 17.56 & 18.7
VOC 21.96 & 22.20

You should get Isc. First find what Isc really is by measuring at the panels with no battery connected, then connect and see what amps you are getting on a low battery.

If panel Isc is less than spec:

-could be some haze
-panel not tipped high enough
-sun not high enough
-temperature doesn't bother Isc so unlikely a factor unless extreme

If panel amps not reaching battery,

-confirm battery voltage is under 13.x
- check wiring

(Your Isc amps will decline slightly once batts get up to 13.x as seen on your panel's IV curve. eg, might see only 7.9 instead of 8.2)

When checking Isc at the panel, aimed at the sun when sun is high, tilt the panel up and down slowly to find max amps.

With 12v and PWM, only the Isc spec means anything. Vmp, Imp mean nothing (those are for the MPPT crowd) Voc means nothing either, since it changes a lot with temperature and when it does , nothing happens with your amps, you still get Isc when Voc is down a whole volt. Ignore all except Isc.

My swivel is at fixed tilt and tilt is a bit low, so I get Isc mid day ok, but when sun is lower earlier and later I get less than Isc with panels pointed at sun. I could get Isc then if I tilted higher for the lower sun. Eventually when the sun is even lower than that early morning/evening, you can't get Isc even when tilted right up because the sun is in atmospherics that low.

I chose the lower fixed tilt for when I just leave it pointing South all day. In that case, you want it lower than perfect for noon so you can get more in the shoulder hours, so there is an optimum fixed tilt for that. There is a formula for figuring that out for each season and latitude at www.macslab.com

Sorry off topic - however my curiosity is killing me

BLF - a question for you
When you go camping in the Provincial Parks - are you on the Pacific coast or inland on the island? I was thinking of exploring Strathcona Park and then on up to SE Alaska

Your beautiful city sure has grown in the past 35 years wow almost did not recognize it - The Butchart Gardens were familiar just several new tourist shops

Yes the STC specs are possible but unlikely to hit in the real world often. Mostly on a very cool sunny day. I think the NOC specs are much more realistic if you can find them for your panel.

BFL That makes sense. If you have to blast, the best batteries are golf cart or better yet fork truck batteries.

Jim

BLF, thanks for your comments.
I have all the specs on the panels, even tho they don't mean much to me.
But I remembered the IMP specs at 5,12a on the 90 watt, and 5.35a on the 100 watt. Add them together for a total of 10.47. Seldom if ever do I buy anything that isn't exaagerated a bunch, so seeing 10.4 output, I was delighted. And that was w/ 2 near full charged batteries, w/ only a bunch of lites on to get the 10 amp output. Not long after turning everything off, the controller would start into float mode w/ only a couple amps output.

ISC 6,15 & 5.72
VMP 17.56 & 18.7
VOC 21.96 & 22.20

Sorry for the confusion. Too much solar for nice days where it does not get so cold at night that we need the furnace a lot at night/early morning. Many days in Spring, not so many in Summer (but some) solar can't keep up, so a shot of gen/charger needed until it gets nice again. IMO having more solar would not help much if any at those times, we would still need to run the gen.

Mostly, the way it seems to work is that solar is almost an all or nothing deal. The times when it is sort of working on dull days is not enough to change the situation that you need the gen until it gets nice again.

We do not have to adjust our use of 12v with the weather; we only adjust how to keep the batteries going as required. The Rv works for us; we don't work for it :)

Different people and systems have different priorities. If you need a genset and it is severely time rationed, getting what you can is the priority. Not too many places limit you to 4 hours a day, but if they do, you have to make it work.

BFL I thought you had too much soar and stopped bulk charge very early in the day?

Jim

Off topic for the solar, but fuel usage, much discussed, is trivial IMO. What counts is the two hours of gen time allowed in the morning here in provincial parks.9-11am. You need high amps fast charging to get anything done in that two hours. (the night time 6-8pm allowance is useless in winter as it is dark by then--who wants to go out there in the dark and do that?) Phooey on battery longevity, the object is to get through the next 24hrs and still have 12v power! :)

In summer in our seasonal site, campground rules allow a four hour gen time 10am to 2pm. This is good , but if doing solar the rest of the day, it is not ideal. For that, you would want to do your gen time earlier and then leave it to solar. Mr Wiz does this routine and it works for his set-up.

Slow charging is much better for batteries than fast charging, but sometimes battery health takes a back seat to fuel usage.

Jim

There is the right way, the wrong way, and the camping way. RVers just have to carry on, and get new batts as required! :)