running my 80l waeco

First , Can you be sure the batteries are in condition i.e. not self discharging etc.

Ian M7,
Mate, I am not sure that 4mm cable is heavy enough as I have 6mm which is at least double the cable area but I don't know what lenght of cable you have run.
As already said, check the condition of the batteries as my 80 Waeco will run at least 24 hrs on one 100A/H battery.
Ian

Ian,

I'm suspicious about your 4mm cable. Could be 4mm diameter copper core. Could be 4 square mm cross sectional area. Might be 4 AWG (or B&S), which isn't its mm size. Ideal sizing for this job would be 4 B&S (minimum 6 B&S) twin from engine bay to batteries and the 6 B&S twin from there to fridge.

4 B&S is a about 5.2mm in diameter, 6 B&S is about 4.1 mm in diameter. If your wire isn't this big you will lose too much voltage along the way and your batteries will not be anything like fully charged by the alternator. Your solar panel will help, but will battle.

While, as others have said, you could have a battery problem, I think I'd first look at your wiring. Monitoring current with an amp meter would be very useful and would probably point you directly to the cause of the problem. A voltage reading at the battery terminals would also be good.

Cheers

John

I presume your fridge run is currently :-o) limited by it's low voltage cutout. A good starting point would be to check the voltage of the supply AT the supply battery and AT the fridge (while running of course). The drop might be unacceptable as mentioned by others. You can carefully poke sharp end multimeter probes into the twinned Waeco cable at the fridge, to ascertain the drop at that point. A standard Waeco cable has a decent drop in itself, let alone any wiring that supplies it - I don't use my Waeco much any more but it I was to, I'd be re-wiring the supply with an Anderson plug and up-spec cable straight into the fridge's board (it's now out of warranty).

Firstly you need to realise that direct cable charging on batteries is rubbish and does not work on modern vehicles regardless of what size cable you use. Those that say it does dont have a clue and correct instruments to measure the state of charge of your auxiliary batteries.
To properly charge your auxiliary batteries would need a DC DC charger like Ctek D250S Dual.
An 80W panel is about 4 panels to little to keep your Waco 80L powered on solar only. While you read these miracle stories like "I run an 80 ltr waeco at -10 on 2 x 120ahr batteries with 120w solar and it does it with ease." they are complete and utter rubbish. You can only power a 40L fridge reliably with a 120W panel as a fridge.

If you want to believe the ridiculous cable charging mantra miracles you will be permanently stuck in power hell. If you believe the ridiculous miracles people post, you will still be caught in power hell. With the power consumption of an 80L Waeco at around 60A+ you can see you are talking serious power consumption and need serious charging equipment. With 2 x 130Ah Trojans and a Waeco 80L depending where you are located would need 3 to 4 and possibly 5 80W solar panels and a quality solar regulator not the normal rubbish some recommend here, and a recognised DC to DC charging system preferably of 40A capacity for your 260Ah of battery capacity.

I will only reply to questions from Ian M7
I only like to soar with competent knowledgeable eagles and don't get drawn in the bull of miracle cable charging systems that don't and technically cannot anywhere near fully charge an auxiliary battery. I am tired of seeing the technical rubbish posted here that breaks all the rules of physics and common sense and basic electrical engineering.

Ian M7,

Once your batteries get so flat that the fridge cuts out you won't get them fully charged with alternator charging or your solar panel. If you are driving a lot every day you might just get by but if you stop for a day or two you will struggle. I have been in this position as have a lot of people and it is a real pain in the backside. All day is spent worrying about the fridge and the batteries. The worst part of it all is that in my case, I didn't have any reliable information on what was actually happening. A multimeter doesn't help at all and sometimes leads you up the garden path. I killed a battery in a four week trip nine years ago and, after some great advice by the local battery bloke, another one the year after. I had to start again with my fridge setup and bought a copy of one of Collyn Rivers books on solar setups.

I don't have an 80l Waeco. Mine is a CF50 and it will use anything from 10 Ah a day to well over 60 Ah a day depending on weather conditions and whether it is on fridge or freezer. I have three 80 watt panels and two 100 Ah batteries and there are times when this is not enough.

I don't know enough about DC-DC chargers or generators etc. to give good advice but if you are going solar then you will need at least another three 80 watt panels (or equivalent) and a good regulator that will give you an indication of what is really happening regarding discharging v charging of the batteries.

You could improve your setup by increasing the wire size and getting the batteries checked by someone competent. You may possibly have killed your batteries like I did.

Getting good advice and understanding it is difficult and you may find it better in the long run to buy a book and teach yourself.

Regards,
Bob

Thanks to all who replied you have all given me some great info, I think I will start with the a battery check under load and get to the cable in the ute from engine bay to the back
Thanks again its been great

Hi, I have the same fridge and live/travel in the north of WA where temps can be 45-50C and nearly 100% humidity at times, temps in the car can get above this of course when parked up.
I run two AGMs inside the car just for the fridge which is also in the car. I found the 4mm is way too small for charge and 6mm too small on the batteries, don't believe people who don't travel in the heat, go humongous and fix it properly !.
My charging wires are a bit thicker than a AAA battery to my Ctek 250 DC/DC 20Amp charger near the batteries, then ( sorry cannot remember specs on the wire) about the diameter of stick welder leads/very heavy duty jumper leads on the batteries. The wire was the largest diameter that would solder into the largest fittings ( that connect the batteries ) without removing any wire.
They do look crazy big but when running the numbers and after trying your diameter ( fitted by ARB who you would think would know), mine needed updating also and as previously mentioned, length of cables can be a killer but mine works well now in the most extreme heat and I don't even hook up a panel if Im only there for two nights.
Measure the length what you need running under the car if need be and do it yourself, soldering the ends and fitting ShrinkFit for a pro job.
My setup runs about 30-35,000 kms a year in the heat and it puts a smile on your dial when you can have a nice coldie or even an icecream after dinner in the middle of nowhere in the stinking heat. Peoples eyeballs pop out and their hands go up when you pull out an icecream in the desert.
I found if you tell the blokes in the shop what you are doing they always steer you to piddly little wire such as you have because they do not know.
Go BIG.

If your Waeco is the fridge AND freezer one then there is nothing you can do. It averages 4A. That means you will drain a 100AH battery in 12 hours.

Waeco make some good fridges but the 80l dual zone one uses way too much juice.

Hi all, I have had the wiring upgraded to 30mm from the front battery to a 175amp anderson connection at the rear to charge bateries, also have had the batteries check under a load tester they seem to only holder 70% of there charge so I'm going to drive around trying to charge them to see if they hold the charge, I think its safe to say theyve had enough thou, does anybody have any ideas on the best kind of battery to buy, I'm think of just buying the one battery with at least 300 amp hrs capcity

Ian