Solar Panell Fridge Combination

Yes, this is WHY it works....

. . SHARP 123Wt solar panels
. . AGM batteries
. . Plasmatronic PL-20 solar Regulator

each item above is "technically advantaged"

Thanks, It looks like 2X 80 watt panels are the go to be reasonably sure of a reliable power supply. Your panel set up is what I was thinking of. Are they charging in the down position when travelling, I mean do you get any stone damage or do you have a deflector ? I have admired those trailblazer fridges, gather you are happy with yours ?

kwk56pt

Watts just ain't Watts...

Now the confusing stuff, the nitty gritty techno stuff not mentioned above..

The test used to give the 80 Watt (or any other wattage) solar panel it's 80 Watt rating is done at "premium" or "best performance" times of the day under "best test conditions" it will state this in the panel specifications booklet, and most often is not obtainable for more than just a few hours per day under decent weather conditions.

Some solar panels use vastly different cell technology to others, there are 3 different solar cell technologies mentioned above in this thread to date.

Just like comparing 'petrol' yes the liquid gold that is still used in some cars whereby some is rated as 'unleaded', some as 'high performance' and some used to be called 'leaded' they were all known as "petrol"
Well solar panels are made with different types of specifications too, some will work better or hotter or colder or longer (start earlier and finish later) than others, but yes, they will still have the same rating in Watts.

You can't compare brand (a) solar panel with brand (b) solar panel even if they are both rated at exactly the same number of watts, because their different technical cell design and inherent efficiency will be totally dissimilar, you have to compare two technically identical solar panels to make any sense of the relevant Amp output number.

One panel will turn 'daylight' into Amps another will not, it has to wait till the sun is shining on the surface of the solar panel before it will start to turn 'sunshine' into Amps.

“Hypothetical” example
(a) start at 10am puts out average 4 amps till 4pm (total 6 hours = 24A)
(b) start at 9am puts out average 4 amps till 5pm (total 8 hours = 32A)
(c) start at 8am puts out average 4 amps till 6pm (total 10 hours = 40A)
(d) start at 8am puts out average 3 amps till 6pm (total 10 hours = 30A)

You have to get the most amps out of every given day, and single charge regulators can't (read as - will not) give you that 'best' result, they in fact will waste your money and time, yes, they do work to a degree, just like budget priced single stage battery chargers are inefficient when compared to 3 stage battery chargers.

Consider a Sharp 123W poly-crystalline solar panel charging two (2) AGM batteries of about 80 to 100 ah each, with a 3 stage solar regulator, not a budget priced, single charge regulator.

Mainey...

kwk56pt

I have never had a problem with stone damage. The panels are connected 24/7 to the deep cycle battery - even when the vehicle is parked at home when I'm not travelling. It helps keep the battery fully charged & reduces sulphation which decreases the battery life. As mentioned on previous posts on this forum I get an average of 6 - 8 years life out of them. I have had the Trailblaza for 25 years now & it has been running trouble free during that period.

To Mainey (WA)

I agree with some of your comments & can only speak from experience. I have been using solar energy & deep cycle batteries for over 30 years, the current setup on my vehicle for some 15 years. The average charge rate I get from my solar panels in sunny conditions is 5 amps & the regulator I'm now using has given me results to my satisfaction. Cheers.

Topcat, good to read someone can come to some agreement... lol
as you say->
"you have had the current setup on your vehicle for some 15 years.
The average charge rate you get from your solar panels in sunny conditions is 5 amps (each) & the regulator your now using has given you results to your satisfaction"

Your solar system is a BP, which feel free to correct me if I'm wrong, would be a 'monocrystalline' panel, yes they will give a maximum 4.97 amps, which is ~5 amps, as you say in good conditions.

However the point I was (attempting) to make was some of the newer technology solar panels available now, will have started to work well before the sun even shines on the panel, I don't believe monocrystalline panels are capable of matching the performance of the new technology panels available nowadays.

I checked my solar reg at 6.55am this morning, well before the panel was anywhere near sunshine as it was sitting between two buildings, there was 0.2 amps going to the AGM's and a total of 0.3 amps current output available, the fridge is connected and would have used power when running during the night, the batteries were fully charged.

Mainey(WA)

Point taken. New technology will give better results but as I said my panels are now 22years old (I had them on another vehicle prior to my present Troopy) & they still perform to my requirements. As the saying goes 'If it ain't broke why change it' & go to un-necessary expense for a couple of extra charging amps!!

I'd be interested to see what life you get out of your AGM's though, as I try to keep mine no more then 25% discharged at any one time (i.e. 75% fully charged). That way I can get more then 800 charge cycles out of them. Cheers.

Mainey(WA)

Point taken. New technology will give better results but as I said my panels are now 22years old (I had them on another vehicle prior to my present Troopy) & they still perform to my requirements. Just another thing to point out - both my panels are connected in parallel giving 160 watts total & I can easily get a charge rate of 8 amps in sunny conditions. As the saying goes 'If it ain't broke why change it' & go to un-necessary expense for a couple of extra charging amps!!

I'd be interested to see what life you get out of your AGM's though, as I try to keep mine no more then 25% discharged at any one time (i.e. 75% fully charged). That way I can get more then 800 charge cycles out of them. Cheers.

Topcat,
I can honestly print here the Fridge "auto disconnect" is set at 11.5v and has never ever been activated.
I can't remember ever seeing the Aux battery guage, and I have 2 of them, reading under 12v.

First thing in the morning, when it's still Dark, the Aux batteries show about 12.4v, this morning at 6.55am it was 13.? volts.

My AGM's are only 13 or 14 months old and I do expect 10 years from them ☺
My last Deep Cycle batteries were 4 yo when I changed them, not because they failed, just that I had the chance to get these new AGM's.

One of the old DC's was given away to run a fridge and the other I still use as my Starter battery, so it's about 5 years old now.
Mainey...