Recharging via generator and/or solar panels

[NinerBikes]

Since I have both options, from a power management perspective, since the 120W folding panel has diodes... must I only run one, or the other, and have a complete disconnect of the input from the solar panel while running the generator, or not? IE, do NOT run both at the same time? After all, this is DC current, not AC.

[time2roll]

A solar controller that hits 14.3+ volts every day will be fine. Equalize every 6 to 12 months is fine.

WFCO at 13.6 will be a sloooow charge on a generator.

[pianotuna]

Hi niner,

A good charge controller may have an equalize function. Using an unregulated 120 watt panel is a short cut to shorter battery life.

[NinerBikes]

smkettner wrote:

NinerBikes wrote:
it's no wonder the generator runs so much, hours wise per day, staying on top of keeping that single 24 DC battery charged up.

So, pretty sure at this point that 2 GC's and another solar panel are in my future.

Assuming you have a 55a WFCO that charges at 13.6 volts..... the GC2 alone will only be a measured improvement. You need more voltage while charging. Solar combined with a new converter will make the new batteries really perform as you expect.

Ideally, with the WFCO, what kind of voltage is required for the GC-2 batteries? I thought I read somewhere that a good 15.1V top off charge 1x a month is beneficial for these? Seems like pretty high voltage for the pair of them for a top off? Unregulated 120W panel sounds like a good way to get there, if monitored carefully.

[pianotuna]

Hi,

The foil at a proper angle would. In the far north panels are installed vertically so that sunlight will bounce off snow cover.

NinerBikes wrote:
OK, next dumb question... If you put a pure white towel, or aluminum foil in front of a tilted panel, will it generate more current when the sun is lower on the horizon, due to more energy reflected into the solar panel?

[time2roll]

NinerBikes wrote:
it's no wonder the generator runs so much, hours wise per day, staying on top of keeping that single 24 DC battery charged up.

So, pretty sure at this point that 2 GC's and another solar panel are in my future.

Assuming you have a 55a WFCO that charges at 13.6 volts..... the GC2 alone will only be a measured improvement. You need more voltage while charging. Solar combined with a new converter will make the new batteries really perform as you expect.

[NinerBikes]

OK, next dumb question... If you put a pure white towel, or aluminum foil in front of a tilted panel, will it generate more current when the sun is lower on the horizon, due to more energy reflected into the solar panel?

[NinerBikes]

12thgenusa wrote:

BFL13 wrote:
Fridge on propane plus LP alarm and stereo clock takes 17AH/day in our rig, when we are away, fridge left on. That was in the summer daytime 80F. If using the rig, don't know fridge draw. The door would be opened and closed many times, which must add to it.

The actual draw is a small amount when the burner is not lit, part of a 0.3a standing draw in the rig. The burner when on takes another 0.5a

About the same on my unit.
LP alarm plus stereo draw .3 for 7.2 Ah/24 hrs
Fridge draws .5 when burner on.
100% duty cycle = 12 Ah
75% duty cycle = 9 Ah
50% duty cycle = 6 Ah

Total Parasitic draw is 13 to 19 Ah.

Assuming 6 AH charge rate from my 120 watt folding panel, 4-5 hours would cover basic fridge and parasitic drag, on a sunny day. No lights, no TV, no computer, no smart phone charging. I can see this is going to take more watts in panels, in the winter Just not enough Ampere hours being made... forget the watts of panels when charging, it's all about charging amps and current being replaced.

Thanks, Every day, I read, I study, I learn more from you seasoned veteran off the grid camper folks. Imitation is the greatest form of flattery. There are some very innovative folks in this forum.

[12thgenusa]

BFL13 wrote:
Fridge on propane plus LP alarm and stereo clock takes 17AH/day in our rig, when we are away, fridge left on. That was in the summer daytime 80F. If using the rig, don't know fridge draw. The door would be opened and closed many times, which must add to it.

The actual draw is a small amount when the burner is not lit, part of a 0.3a standing draw in the rig. The burner when on takes another 0.5a

About the same on my unit.
LP alarm plus stereo draw .3 for 7.2 Ah/24 hrs
Fridge draws .5 when burner on.
100% duty cycle = 12 Ah
75% duty cycle = 9 Ah
50% duty cycle = 6 Ah

Total Parasitic draw is 13 to 19 Ah.

[SteveAE]

NinerBikes,

I suspect that parasitic loads will vary by rig. Here are mine:
- Propane detector 70mA
- Display on clock radio ~100mA (can disable if needed)
- Two digital displays and several LED's ~100mA
- Refrigerator 400mA (when cooling, less in standby)

For a total, maximum (in hot weather), parasitic load of 770mA or 18.5 Amp-Hrs./day.

At 8AM this morning, in solid overcast conditions, with the trailer parked in the shade (if there were sun) of my barn, my solar system (300 W) has already recovered all of the parasitic losses (except refrigerator which is off) from last night. Love that solar.

Hope this helps,
Steve

[pianotuna]

Hi nine,

At least in my experience, there is, with proper care about zero difference in lifespan. My previous walmart group 29's lasted 9 years until the new owner decided that the old magnatec converter should be plugged in 24/7. That did them in. My current bank is 3 at 4 years old and 4 at 8 years old.

If I could fit in 2 volt cells (@ 800 amp-hours) I'd go for them. But there is no way to get them to fit.

[NinerBikes]

BFL13 wrote:
Fridge on propane plus LP alarm and stereo clock takes 17AH/day in our rig, when we are away, fridge left on. That was in the summer daytime 80F. If using the rig, don't know fridge draw. The door would be opened and closed many times, which must add to it.

The actual draw is a small amount when the burner is not lit, part of a 0.3a standing draw in the rig. The burner when on takes another 0.5a

This pretty much confirms that unless I am staying at a park with hookups, it's no wonder the generator runs so much, hours wise per day, staying on top of keeping that single 24 DC battery charged up.

So, pretty sure at this point that 2 GC's and another solar panel are in my future.

[BFL13]

Fridge on propane plus LP alarm and stereo clock takes 17AH/day in our rig, when we are away, fridge left on. That was in the summer daytime 80F. If using the rig, don't know fridge draw. The door would be opened and closed many times, which must add to it.

The actual draw is a small amount when the burner is not lit, part of a 0.3a standing draw in the rig. The burner when on takes another 0.5a

[NinerBikes]

pianotuna wrote:
Hi nine,

That depends. I had room for three group 29 12 volt jars. I decided to upgrade to seven of them, giving up a compartment.

2 golf cart six volts still only get you to about 220 amp-hours. 2 group 29 may do 230 amp-hours.

Yeah, but 2 GC's will last a lot longer than a couple of WalMart special Group 29's, and get a lot more recharge cycles.

I've got a start on some solar, and I've got plenty of generator too. For like when I feel like nuking a TV dinner instead of cooking, for more time to tie flies before going fly fishing the next day.

[pianotuna]

Hi nine,

That depends. I had room for three group 29 12 volt jars. I decided to upgrade to seven of them, giving up a compartment.

2 golf cart six volts still only get you to about 220 amp-hours. 2 group 29 may do 230 amp-hours.