Solar Trickle Charger for Storage

[nighthawk87]

Does anybody have any inexpensive solar trickle chargers I can get that plug into my “solar prep” connector on my trailer for whole it’s in storage?

I can’t imagine it needs that much power going to it to keep it topped off.

[nighthawk87]

Originally Posted by nighthawk87

Does anybody have any inexpensive solar trickle chargers I can get that plug into my “solar prep” connector on my trailer for whole it’s in storage?

I can’t imagine it needs that much power going to it to keep it topped off.

Seems amazon has some but it’s unclear if the 10W versions require a charge controller. Wouldn’t want to ruin my batteries. Is 10W @ 18v or so ok? The .5amps it has will be perfect for maintaining a charge on my batteries.


Sent from my iPhone using Tapatalk

[retiredtech]

A friend asked me to give his a try, because he didn't think it working. As I recall it was rated 18 volts at 15 watts. Keep in mind those ratings are absolute maximums under full sun. Anyway, the most I could get out of his with no load was about 14 volts. That was high noon on a sunny day. There was no way it was ever going to trickle charge a battery.

It appeared to be a cheap import and maybe some solar low wattage trickle chargers do work to some extent. None of them seem to have a controller or regulator, but I don't there is much danger of harming your battery. If they ever put out anything like their ratings, it would only be for a few hours each day.

[nighthawk87]

So is the consensus that the most cost effective way is to install a full blown solar kit on my roof? 100W min for the trouble, if not 200W. Now I’m looking at $400 just to maintain my batteries in storage....


Sent from my iPhone using Tapatalk

[Mustang65]

Originally Posted by nighthawk87

So is the consensus that the most cost effective way is to install a full blown solar kit on my roof? 100W min for the trouble, if not 200W. Now I’m looking at $400 just to maintain my batteries in storage....
Sent from my iPhone using Tapatalk

As mentioned in an earlier post the SOLAR panels produce the most power from about 11AM - 1PM. On the 12VDC panels the power drops pretty fast. In most cases, you may get an hour of max sunlight, with not clouds, shade or rainy days. When your panel only puts out .5 amps in full sun, your chances of keeping the battery topped off are slim to never. .5 amps will not even produce enough power to run your parasitic loads (CO, fridge circuit board, radio circuit board,,) should the TT be connected to the batteries

ALL SOLAR panels need a SOLAR charge controller, whether it is an inexpensive PWM or MPPT controller. They insure that the batteries do not get over-charged and that the SOLAR panels (without blocking resistors) do not drain your battery at night. At night a SOLAR panel acts like a load.

As for how much SOLAR, that depends... one standard RV/Marine battery 85Ah, (2) T105 6 volt batteries (220Ah), both need different amounts of power to keep them topped off. A 50Watt SOLAR panel will give you about 4 amps for a couple of hours a day, with less the rest of the day. That would keep a standard battery topped off... PROVIDING the panel is clean, plenty of sun, not many clouds or rainy days. If you ever looked at a SOLAR panels output during a single 8 hour day, it looks like the silhouette of the Rock Mountains. As each cloud passes over the output nosedives.

Personally, I do not like to recommend a SOLAR system that is less than 100 Watts. Why, you have a lot more output and that is spread over more hours. You are producing more power with clouds and even on rainy days, where the small cheap ones drop off.

The nice part of installing a 100 watt (Example - Renogy kit), is that if down the road you decide to add more SOLAR for dry-camping, just add them on. The cheap/small system will land on a shelf in your garage, money wasted.

$169 is a lot better than $400.

Don

My Registry

RVing with SOLAR

[nighthawk87]

Thanks don. I’m going to just do the 200w Renogy kit. Problem is finding a way from the roof to inside the trailer. I get 20’ if wire and have to mount panels up front. All the vents and such are at the back of the trailer. Only penetration is the tv antenna. Has anyone leveraged that anyway to reduce holes? Other option is to just pop a hole in the roof but not sure how I’m going to seal that.


Sent from my iPhone using Tapatalk

[Mustang65]

Originally Posted by nighthawk87

Thanks don. I’m going to just do the 200w Renogy kit. Problem is finding a way from the roof to inside the trailer. I get 20’ if wire and have to mount panels up front. All the vents and such are at the back of the trailer. Only penetration is the tv antenna. Has anyone leveraged that anyway to reduce holes? Other option is to just pop a hole in the roof but not sure how I’m going to seal that.


Sent from my iPhone using Tapatalk

I ran my cable inside 5/8" plastic wire channels from Lowes. My run goes from the back to the front just under the awning. I ran the wire channel next to the awning bracket and put a small hole into the storage area where I have the MPPT SOLAR charge controller.

I used Dicor 501LSW Self-Leveling Lap Sealant, in the hole and it is as good today as it was 5 years ago. You can also use the Dicor to hold down the cable on the roof also.

Don

My Registry

RVing with SOLAR

[nighthawk87]

If I decide to use the fridge vent and need more than the 20’ they provide, do I just buy 10awg wire and a butt connector OR do I buy a new 30’ 10awg wire?


Sent from my iPhone using Tapatalk

[Magnolia Tom]

Don

What size solar set up do you suggest for those of us with residential refrigerators using inverter while driving? I’ve been considering solar because powering the fridge via the inverter while driving 4-5 hours really drains the batteries and the truck can’t keep up with recharging the trailer batteries


Sorry op for hijacking

Sent from my iPhone using Tapatalk

[nighthawk87]

Also, where is everyone getting their wire?


Sent from my iPhone using Tapatalk

[Mustang65]

Originally Posted by Magnolia Tom

Don

What size solar set up do you suggest for those of us with residential refrigerators using inverter while driving? I’ve been considering solar because powering the fridge via the inverter while driving 4-5 hours really drains the batteries and the truck can’t keep up with recharging the trailer batteries


Sorry op for hijacking

Sent from my iPhone using Tapatalk

Here are a few threads regarding the Residential Fridge. Klassic has first hand experience in this area and does some GREAT explaining in them.

https://www.jaycoowners.com/forums/f...tml#post613881
https://www.jaycoowners.com/forums/f...mod-47511.html

Don

My Registry

RVing with SOLAR

Don

[Mustang65]

Originally Posted by nighthawk87

Also, where is everyone getting their wire?

Sent from my iPhone using Tapatalk

Here is the link to the other thread regarding wire.

https://www.jaycoowners.com/forums/f...tml#post613897

Don

My Registry

RVing with SOLAR

[Magnolia Tom]

Thanks Don. I forgot Klassic had a fridge mod


Sent from my iPhone using Tapatalk