Renogy solar?

Hi,

I'll probably regret this, but.....

875 amp-hours of battery bank would get me through five days of my typical energy use, provided I only use my smallest inverter for only laptop charging, without going below 50% state of charge. In addition I get 7 amps of charging in leafy shade, and 3 amps when in a rain storm. If I take the lower number of 3 amps x 5 hours then 15 amp-hours are returned to the battery bank daily. After 5 days that is 75 amp-hours returned to the battery bank. That's enough for another day without generator power.

So after six days of cruddy weather, I'd be forced to start the engine on my class C and let the alternator recharge the battery banks at 70 amps. An hour would "buy" me another day. If DJ upgraded his charging path from the alternator, he could do lots of charging too.

As I am mostly a traveler, rarely staying more than two nights in one location, I have no need for a generator. I run out of grey tank room before I run out of electricity as my RV has an extra fresh water tank (OEM installed).

Here is a "formula" for you to follow:

energy audit result X 10 = amp-hours of battery bank X 60 watts of panels per 100 amp hours of battery bank.

I'd recommend DJ look at Sleepy's truck camper solar install. He doesn't generally use any generator power either.

harold1946 wrote:

pianotuna wrote:
Hi DJ,

I have no generator and no intentions of getting one. It is entirely possible to design a solar system for even a truck camper that will essentially eliminate generator use. It is a one time cost.

That has to be a truly amazing solar system you have. I have never seen a system of any type that can essentially go for an unlimited amount of time without the need for an alternate means of charging the battery bank if there is not enough sun.:B
You should patent and market that system, it would be an industry first.:S

trail-explorer wrote:
I've never seen 11 awg wire.

Neither have I. Just going by the specs listed for the system (4.0 square mm cross section, which is roughly 11 gauge according to this chart).

harold1946 wrote:

pianotuna wrote:
Hi DJ,

I have no generator and no intentions of getting one. It is entirely possible to design a solar system for even a truck camper that will essentially eliminate generator use. It is a one time cost.

That has to be a truly amazing solar system you have. I have never seen a system of any type that can essentially go for an unlimited amount of time without the need for an alternate means of charging the battery bank if there is not enough sun.:B
You should patent and market that system, it would be an industry first.:S

I respectfully disagree. I have 'only' 100 watts, but in 5 years I've never plugged in my camper to any 120V source, home or generator, and the batteries have never been below maybe 12.35 volts, even on an extended winter trip in the shade. I store it under a big ole' walnut tree so it's well shaded from May through November. But this is in Califormia, not Canada. So I have never had to 'winterize' it either, since below freezing conditions never last for more than 12 hours or so.

pianotuna wrote:
Hi DJ,

I have no generator and no intentions of getting one. It is entirely possible to design a solar system for even a truck camper that will essentially eliminate generator use. It is a one time cost.

That has to be a truly amazing solar system you have. I have never seen a system of any type that can essentially go for an unlimited amount of time without the need for an alternate means of charging the battery bank if there is not enough sun.:B
You should patent and market that system, it would be an industry first.:S

Hi DJ,

I have no generator and no intentions of getting one. It is entirely possible to design a solar system for even a truck camper that will essentially eliminate generator use. It is a one time cost.

Sure appreciate your time folks!!

I guess what my goal is as far as solar is for a "little help" when camped in the right locations. I don't plan to never run my genny again. That is not possible. My TC does not have AC so in the heat of summer I'm heading for the high mountains and camping in the shade of forests.

This is why I'm leaning toward a smaller less expensive system. Then in the Spring/Fall it would help me out a little camping in more open areas.

My TT came from factory with a 15 watt solar and it keeps my batteries charged all winter which also powers some electrical stuff like alarms, tv, etc. IF I keep the snow off!!!

I've never seen 11 awg wire.

Don't have any personal experience with it but took a look at this one online. Someone on these forums has one installed and was asking questions about the controller. It appears to come with:

1. 11 gauge wire, ten feet

2. Cheap Chinese PWM 10 amp charge controller (which would probably work fine on 12v batts). Can't be certain about the PWM part since the ad says nothing about it, but it appears very similar to others I've seen that are PWM.

3. 100w monocrystalline panel

Couldn't tell you anything about the company itself

If you have 6v batteries this will probably undercharge them a bit. Most cheap charge controllers don't allow setting absorption stage set point to 14.8v, which flooded golf cart batteries typically need. Could still be fine as long as you equalize the batteries regularly. Shouldn't be a problem with 12v batts.

How many amp hours is your battery bank and what is your intended use of this system? If you've got a couple of batteries and want to be able to stay out on extended trips without hookups or generator and without running batteries below 50%, you will probably need more than 100 watts, in which case you'd be better off with a different system than this (can't add many more watts to this controller). Otherwise, it will probably be fine. Many report good results with cheap Chinese PWM controllers.

Edit: Saw your other thread about the fridge. This should work fine if you only want to run the genny less often, but it probably won't keep up without the genny on extended trips when 48 amps per day are going to that fridge alone.

I can not comment personally, but the reviews I have read are all very good about the company and their panels.

Hi DJ,

Give us a link to look at it?

100 watt system for $179

I do not think 100 watts is enough.

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT.

Here is a link to the rather special spreadsheet that N8GS has created to help size solar battery charging systems!

Solar spreadsheet by N8GS