Simple solar setup

Quote:

---

Originally Posted by steveG

Will that setup run indefinitely on just the solar, or is the battery voltage getting low after a few days if you don't run the engine?

Steve

---

I can't remember ever having had to recharge the second battery. We have camped for up to a week no problems.
If your tradie son is driving to and from worksites on week days he should have no problems staying charged.
There used to be a solar calculator on the Redarc site which could accept proposed details to give an idea.
Still, more is better with solar.

I fitted the 110W king's panel and 15amp MPPT controller to my tool box after I had finished using it for the Canning trip.

It charges a 55Ahr Exide battery similar to the D34 Yellow top and runs a 40Lt Engel upright set to just the 1 side of 2.

It's been going since October sometime and the voltage has never dropped below 12.8V.

This fridge is in a steel clad toolbox with no additional ventilation and is in direct sun for better part of the day.

Keeps those bottles and cans of relaxing beverages Icy cold!

Slight sidestep, but anyone have experience with this company or these batteries:
130AH Deep Cycle AGM Battery | Eclipse 12 Volt 130ah Deep Cycle Battery | 130AH AGM Battery

Steve

Quote:

---

Originally Posted by garrycol

My experience is not quite the same - most MPPT chargers are basically a 3 stage charger and in winter I found there was not enough daylight for the MPPT to go through its full cycle and this resulted in the battery not being fully charged at the end of the day. I put a Dr Watts meter on it and I found the old style straight regulator which just provides charge worked better as it got more charge quicker into the battery before the sun disappeared. Not as good for the battery though.

Not an issue with longer daylight hours in summer where the MPPT worked fine as it had time to go through its full cycle but not in winter.

Though, on the basis of the readings from my Dr Watts meter, there was not a lot of difference in overall charging from the cheap reg my solar panels came with and the MPPT reg I bought.

I am sure the MPPT is better for the long term health of the battery though.

Garry

---

Not noticed that issue. My (very rough) calculations when I went from a PWM to MPPT showed nearly 25% at best and around 10% at worst so I averaged it at 15 ish... Found during overcast days and shorter days is when it worked best compared to a PWM to be honest. Only back of the envelope type calculations so not saying they were terribly accurate though.

Quote:

---

Originally Posted by Konradical

It's been going since October sometime and the voltage has never dropped below 12.8V.

!

---

What do the volts drop to overnight

Quote:

---

Originally Posted by weeds

What do the volts drop to overnight

---

Not 100%

Up north you could hear it cycle twice an hour for about five minutes a cycle, but by the time I got outside to test it, it was generally already charging and sitting around 13.1-13.3V.

Down here, SA, I generally hear it cycle at most once an hour and short 5 minute cycles at that. Haven't had the time to check voltages. It's too cold down here to start drinking in the morning.

(Above is at night)

Il endeavour to get one of those Bluetooth monitors on it and actually watch what it's doing. Who knows, it could drop below what I have stated.

Quote:

---

Originally Posted by Konradical

Not 100%

Up north you could hear it cycle twice an hour for about five minutes a cycle, but by the time I got outside to test it, it was generally already charging and sitting around 13.1-13.3V.

Down here, SA, I generally hear it cycle at most once an hour and short 5 minute cycles at that. Haven't had the time to check voltages. It's too cold down here to start drinking in the morning.

(Above is at night)

Il endeavour to get one of those Bluetooth monitors on it and actually watch what it's doing. Who knows, it could drop below what I have stated.

---

12.8 is fully charged (6 x 2.1). Surely it would drop overnight?

Quote:

---

Originally Posted by DiscoMick

12.8 is fully charged (6 x 2.1). Surely it would drop overnight?

---

It probably does, but I don't know what it drops to.

12.8V was measured with fridge cycling, middle of a 40 degree day up north. That's the lowest I have seen it go.

Like I said, once I get something on it to record overnight voltages I can more accurate in my findings.

80w on an n55 runs an engel for 3 days starting with the n55 fully charged and winding up with it at nominal flat voltages.

(the old engles will draw down to 6v)

If you have a look at the data logs I copied in
The lowest battery min voltage I’m getting is 12.24
Most nights it only drops to 12.4

This is in SEQ Average day temps in 30s (Engel in sun)
Overnights high teens

I really think with a good controller, 100 plus AH battery and 120-180W of panel you’ll be fine