DIY for Rv only

[anony]

This single battery is in a ent Trailer (Pop Up) so it's a bit tough to always hookup and charge. Battery does charge while I am pulling it. If we are careful I can make it last 3+ days but we are out for up to 2 weeks at a time. Would a 50W system work to keep the battery topped up?

I would add up all your electrical needs and at least double the solar panel wattage, which will allow for days with little sunlight.

Another factor is the type of solar panel. Some panel types are more efficient under low light conditions while others are more efficient when used with direct sunlight.

[SunEagle]

Wow this is great info!!
Ok so I search eBay for a 140w solar kit and find a pile of them in china for a good price. Why should I NOT buy these?

Two things to worry about when you purchase "no name" PV from China. Sometimes the quality is not there and you may have to pay an "import tax" on top of the shipping. Check the fine print to see if all taxes & tariffs are included in the price.

[russ]

Wow this is great info!!
Ok so I search eBay for a 140w solar kit and find a pile of them in china for a good price. Why should I NOT buy these?

If you need a boat anchor or have a desire to contribute to a shyster's pocket please go ahead.

Like Amy said - you get what you pay for.

[Amy@altE]

Because you get what you pay for.

[Vallka1]

Wow this is great info!!
Ok so I search eBay for a 140w solar kit and find a pile of them in china for a good price. Why should I NOT buy these?

[Amy@altE]

But he says he can make it last 3 days. I suppose the big question is, what does "lasts 3 days" mean? Use it all the way down to dead, or to 50%?

The problem with going bigger than 140 or 145W, is there aren't a lot of 12V panels any bigger than that. Then you'd have to jump up to 20V and MPPT charge controller.

I still vote Kyo140 (or similar) with PWM charge controller, and if they need to, they can hook up and charge from the truck every now and then. Or a compromise of a Genasun GV-10-Pb-12V for $145.

[Sunking]

If we are careful I can make it last 3+ days but we are out for up to 2 weeks at a time. Would a 50W system work to keep the battery topped up?

OK assuming it is an 80 AH battery tells us you are using about 300 to 400 watt hours per day. Assuming you are going to use a PWM controller, mounted flat on top of the RV, and have and have direct Sun from Dawn to Dusk with no shade is going to take 150 to 200 watts of a panel to replace that energy every day. If shaded no amount of power will work.

[Amy@altE]

The Kyocera 140 is wildly popular for RVs. And a decent compromise between my 80W and SunKing's 160W.

[Sunking]

80 watt panel is a bit on the lite side if using a PWM charge controller as that would only generate up to 4 amps or C/20 on a 80 AH battery. You need to get up to at least C/10 to do any good or a 160 watt panel.

[Amy@altE]

A 50W would work, an 80W might do better. Make sure you also use a charge controller sized correctly for the panel. Take the panels Isc x 1.25, that's the smallest size charge controller to use. For example, a 50W has an Isc of 3.03A, so you should get a 4A or bigger charge controller (like a Morningstar SunGuard-4).

[Vallka1]

This single battery is in a ent Trailer (Pop Up) so it's a bit tough to always hookup and charge. Battery does charge while I am pulling it. If we are careful I can make it last 3+ days but we are out for up to 2 weeks at a time. Would a 50W system work to keep the battery topped up?

[Sunking]

How big is the battery bank and/or how much power will you be using in a day?

In an RV it would be advisable to still have a battery isolator so you can charge the batteries off the engine alternator.

WWW

Ditto for a BCI 24 battery the alternator can fully charge on in half an hour. No need for solar.

[Wy_White_Wolf]

Ok thanks for the info, so for what I am looking for what watt output panel should I be lookig for?

How big is the battery bank and/or how much power will you be using in a day?

In an RV it would be advisable to still have a battery isolator so you can charge the batteries off the engine alternator.

WWW

[Amy@altE]

Group 24, so probably about 79Ah hybrid battery.

[Vallka1]

No Ah rating on the battery but these are the spec's I found online.
G24RV
PART NO. (CE):
G24RV
PART NO. (BCI):
24 RV

PERSONAL WARRANTY:
18 MONTHS

COMMERCIAL WARRANTY:
3 MONTHS

VOLTS:
12V

COLD CRANKING AMPS:
450

CRANKING AMPS:
550

RESERVE CAPACITY MINUTES:
130