Coast Resorts Open Roads Forum: Travel Trailers: Solar Charger


	Already a member? Login here. If not, Register Today! \| Help

Newest | Active | Popular | RVing FAQ

Forum Rules | Forum Help and Support | Contact

Open Roads Forum > Travel Trailers

This Topic Is Closed | Print Topic | Post New Topic |

pryan

New Hampshire

Full Member

Joined: 07/25/2010

View Profile

Offline

Posted: 09/08/10 07:29pm

Link | Print | Notify Moderator

Hi folks,

I know that there are threads on this topic and I've looked at them. I'm really just looking for the answer a simpleton like me needs. This past weekend our battery died after a couple of days. No hookups! I think a solar charger might be the answer. I have a TT with the normal "stuff.". I don't know about amps or loads or any of that stuff. What solar charger should I get?
Thanks!

Jimehc

Taylorsville, Kentucky

Senior Member

Joined: 07/01/2010

View Profile

Posted: 09/08/10 07:34pm

Link | Print | Notify Moderator

if you are looking at no hook ups - the biggest you can afford..

Solar chargers a rather low output - thus they maintain a charge rather then pull a load..

A 26 watt solar charger is around $300 and will only light 1/2 of a double bulb 12v light fixture.

A double bulb light fixture has (2) 18 watt bulbs - and pulls 36 watts

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile

Offline

Posted: 09/08/10 08:30pm

Link | Print | Notify Moderator

Hi Jimehc,

Solar panels now cost less that $2.00 per watt if you shop around.

Hi pryan,

For solar to work well the range of wattage is best between 60 and 150 watts of panels per 100 amp-hours of storage. Less than 60 watts may not be able to equalize the battery bank (but even 15 watts per 100 will, given enough time, fully charge the bank). There are reasons to use more than 150 watts--but after the battery bank is 85% charged there is not much point in attempting to charge faster than the c/8 rate.

Charging a battery bank is somewhat like a frog on a log who can jump 1/2 to the end of the log in any jump. Every jump takes about the same time but the amp-hours returned to the battery become smaller and smaller. That's why solar, with a good charge controller, is one of the better ways to recharge batteries. It is not uncommon for me to see my solar panels "putting in" just one amp to 875 amp-hours of storage.

Regards, Don
Kustom Koach Class C 28'5" 256 watts solar, 875 amp hours in two battery banks 12 volt batteries 2500 watt inverter.

RicJones

So. Cal.

Senior Member

Joined: 10/29/2007

View Profile

Offline

Posted: 09/08/10 10:02pm

Link | Print | Notify Moderator

If you generally camp under trees then solar probably isn't for you, maybe a generator would be a better investment. Solar needs lots of sun to work.

Jimehc

Taylorsville, Kentucky

Senior Member

Joined: 07/01/2010

View Profile

Posted: 09/08/10 10:49pm

Link | Print | Notify Moderator

pianotuna wrote:

For solar to work well the range of wattage is best between 60 and 150 watts of panels per 100 amp-hours of storage. There are reasons to use more than 150 watts--

Charging a battery bank is somewhat like a frog on a log who can jump 1/2 to the end of the log in any jump. Every jump takes about the same time but the amp-hours returned to the battery become smaller and smaller.

That's why solar, with a good charge controller, is one of the better ways to recharge batteries. It is not uncommon for me to see my solar panels "putting in" just one amp to 875 amp-hours of storage.

150 watts per 100 amp hour of storage - with 875 storage

150 x 8.75 = 1312.5 watts of panel needed

1312.5 x $2 per watt = $2625

That is, if my math and your statements are correct and then we need to purchase a charge controller too??

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile

Offline

Posted: 09/09/10 05:31am

Link | Print | Notify Moderator

Hi Jimehc,

Ah but my two battery banks are switched, so I can still equalize with fewer watts--and I went for 60 watts per 100. So I have 256 watts X 2 = $512.00 plus an MPPT charge controller (less than 100 on ebay) plus various other items (call it 100 more) so $712.00 would "do the deed".

This is not helpful to the OP. I suggest having a look at panel prices here:

low cost high quality panels

Further, Jimehc, have a look at this 180 watt panel for $320.40 180 watts not 26 watts

* This post was last edited 09/09/10 05:51am by pianotuna * View edit history