Solar charging 40litre Engel fridge

Hi John
Do not under any circumstances connect the Engel direct to a solar panel
You will do serious damage to the inbuilt inverter
Solar must always be connected to a battery not used on its owni
This is a good option:
"My other idea is to run a lead off our dual 120ah hour agm batteries in the caravan which are charaged off a 80w and 125w BP solar panels. We are about to go across the Nullabor and are getting a bit nervous. your response to this thread is greatly appreciated. Cheers all John"

If the battery which has given up was regularly discharged below about 50% capacity [12.3 v it will have a very short life.
What size battery is it & @ what setting temp wais are you running the fridge??
Are yor van batts also being charged by alternator ??

Johny boy,
We used to recharge our second battery via a solar but found the solar panel was to small a voltage to maintain enough power in the battery.

We have a similar amount of watts in panels as you, and have since made up a lead with an anderson plug on one end and attached the other end to one of the batteries in the van, made up another lead of about 4 meters with an anderson plug on one end and on the other end a plug to match the fridge and have been stationary in the one spot for four or five days and had no trouble.
Hope this helps.
Enjoy the Nullarbor, we did.
Cheers
Baz

If you have a new Engel it should cut out at 11.5 or whatever.

if an old one like mine at 10 years, then it will just keep trying to run until the battery is completely flat. If you have an older Engel then you should fit a low voltage cutout. I have had a "Projecta " one in the line for 10 years with no problems.

You will need at least an 80watt panel, and comfotably a 120 watt to keep up with an Engel on hot days, hot nights.

It is also an idea to have a monitor to know your battery condition. I have a $30 JAYCAR one and it helps a lot in managing the batteries. You can always go for a drive if the battery is quite down or sometimes 1/2 hour idling will input enough to last the night.

John,

You haven't mentioned what capacity and type of second battery you are using.

An 80 Ah deep cycle battery should keep the Engel running for around two days before it requires recharging. This is assuming you are not using the Engel as a freezer.

I have been camped for four days and used a 40 watt solar panel to maintain a reasonable charge in the 75 Ah Thumper battery system I run the fridge (and lights) off. I would regard a 40 watt panel as a bare minimum.
I have added another 40 watt panel but the longest I have been in the one place is 5 days.
The 80 watt panel will maintain a near full battery indefinitely as it is capable of putting in a constant 5 amps or so during daylight hours and the fridge is drawing somewhere less than two.

When driving, an auxiliary battery should be able to receive a charge of 30 amps and recharge the battery in a few hours, even if running the fridge from it at the same time.

I also charge my auxiliary 100 Ah Remco and the 75 Ah Thumper from in-car charging kits whilst travelling.

Bill.

Your 40 L Engel uses on average 24 - 36 Amps daily ...

That means Solar wise - 6 hours at 6 Amps to maintain your battery ..

A 100 watt foldable kit would do the job easily .. the 205 watts you have available will do it even better !! As said above a decent twinflex lead and a few Andersons and you're in business .. $60-80 as against a foldable kit at $400 ..

Cheers

Steve

Johny Boy

I assume you must have a power hungry van given the panels and batteries you have.
If you van set up has spare capacity from the 240 amphours ( by christ that a l ot, each to thier own), then a simple cable from the van to the car would be the go. I suggest that you would need to add up your power usage for the van and the power production from the existing panels and see what's left. Also get your car and van charging circuits checked along with the Aux batteries to confirm that all is good in that area.
At the risk of stating the obvious have the engel set at a temp that is correct for the contents not just running flat out because you can.
cheers
Trevor

John,
If you are not onto it thread 77788 might be worth watching.

Johny Boy,
I appreciate Ally CT's comments however, no one would actually use a battery system without providing a means of keeping the batteries charged as you are using them.
Just draining them and recharging them when you are finished is not wise.
BTW do you have an AC charger for the Van batteries?
Cheers
Trevor