Simple solar setup

[steveG]

Helping my son in law with a simple solar setup on his tradie trailer for a 60L Waeco running as a fridge.
What he's trying to achieve is a setup that will just sit happily and run 24x7 without needing to be plugged into a charger. Its always outside from a solar perspective (ie not garaged over the weekend etc).
Worst case if he's having to plug in the charger over the weekend during winter to get the battery topped up I'm sure he'd cope with that.

So far he's got a 240W panel, and a used 130Ah AGM and 15A charger which I had spare at home and he's using a Morningstar 30A regulator that I loaned him when his $16 cheapie spat the dummy after a couple of weeks.

So, first question (so I can get my regulator back!!) - whats the up to date recommendation for a solid no-frills 30A regulator? A built in voltage display would be nice but not essential.

Secondly, a bit of Googling suggests that the Waeco is likely to consume around 24Ah per day.
I'd expect the panel to supply enough to power the fridge during daylight hours even on poor solar days, but time will tell I guess. Assuming that as a worst case, then he'd only be drawing 12Ah/day from the battery, so a 100Ah one should seem him through the week at around 60% discharge.
Does that sound reasonable?
I'm thinking a battery in the 100-130Ah range would suit - any recommendations on size/type/brand etc?

Steve

[weeds]

umm, 24amp/hrs per 24 hours...........that's 1 amp/hr per hour in a metal clad trailer

i'd reckon it will use more than that.......especially in summer

I use fullriver batteries and victron regulators......these are probably at the other end of the market that your son is chasing

[goingbush]

I have a Waeco 28L in between the front seats of my Iveco, connected to a 100Ah Aux battery under back seat, 5year old chinese eBay 30A MPPT solar charger and a 280watt house panel the roof , Its run 24-7 for 5 years no problems . Im sure they have the same compressor as the 40L .

I have it connected to the Main battery by a Isolator so when the Aux battery is full it keep the main battery topped up. Works a Treat.

[Homestar]

Agree with Weeds, in a enclosed trailer in Summer it will likely use a lot more power - I run my Engel in my Hilux all Summer to keep my lunch and drinks cool and it runs about 60% of the time on a warm day - about twice as much as what it does when outside on a similar day. Not an issue for me as the car does a couple of hundred K's a day but running it off solar you may need a bit more that what you're planning.

I would suck it and see though - you can always add to it - 240 watts of solar and a 120Ah battery or so will be a good start. I too use Fullriver batteries but there are other good ones out there - and there are a lot of crap ones too, so be careful.

A MPPT charger will get 15 to 20% more into the battery per day so worth spending the extra money on one - Victrons are the best IMO, but again, there are others. If you look at ebay regs and it says MPPT but is as cheap as a PWM unit, it won't be a MPPT - there's a lot of BS out there on these too.

[steveG]

Good point about the environment. I hadn't considered that.
I suppose its all just assumption and guesswork without any real data. Maybe I should start with something like this to capture some: KickAss Digital DC Watt Meter for Portable 12V Solar Panels

Steve

[101RRS]

A MPPT charger will get 15 to 20% more into the battery per day so worth spending the extra money on one

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

[DiscoMick]

I have an 80 watt panel on the Defender's roof rack connected to a PWM regulator next to the starting battery which is linked to a 110 amp second battery through a Traxide DBC to run a 30 litre Evakool fridge and it works fine.
Keep in mind the temperature setting on the fridge and how much stuff is in the fridge will make a lot of difference to how frequently the fridge switches on and off. The emptier the fridge the more power it will draw.

[steveG]

I have an 80 watt panel on the Defender's roof rack connected to a PWM regulator next to the starting battery which is linked to a 110 amp second battery through a Traxide DBC to run a 30 litre Evakool fridge and it works fine.
Keep in mind the temperature setting on the fridge and how much stuff is in the fridge will make a lot of difference to how frequently the fridge switches on and off. The emptier the fridge the more power it will draw.

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

[roverrescue]

I run two 60W panels (eBay cheapies) in parallel feeding a VictronConnect 75/15 controller to a 130AH AGM running a 40L Engel
It runs indefinitely, battery will always get to second stage and most days will get to float
I honestly just park the Ute in the sun so fridge works hard but solar needs juice!

A few days last week I had a bunch of steel on the rack which zeroed the output but next day full sun and she catches up quickly?

Steve

[roverrescue]

A few screen grabs from the VictronConnect data logger
Can see just 120W of panel makes enough juice as required
Fridge consumption seems to wander around a bit even though it is always generally half full?

Steve