running my 80l waeco

Submitted: Monday, Jun 06, 2011 at 08:40
ThreadID: 86788 Views:5098 Replies:10 FollowUps:7
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Hi all
My problem is running a 80l waeco whilst I'm out traveling I have a 2007 4X4 Rodeo, with a connection in the tray back that was wired by the local car elec in 4mm cable so that when I start my car it charges my 2 Trojan deep cycle scs225, 130 amp hrs each batteris.
when I stopped I use a 80 watt solar panel to keep the batteris topped up
The battery connection are all anderson and in 6mm, but my fridge wont run for any longer then over night
Can some one please help me, I'm banging my head agaisnt the wall ( not fun )
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Reply By: Robin Miller - Monday, Jun 06, 2011 at 08:46

Monday, Jun 06, 2011 at 08:46
First , Can you be sure the batteries are in condition i.e. not self discharging etc.
Robin Miller

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AnswerID: 456539

Follow Up By: Ian M7 - Saturday, Jun 11, 2011 at 07:26

Saturday, Jun 11, 2011 at 07:26
When I charger the batteries up they might charge to 12.8v say but they always drop down to around 12.06 ish, does this mean there stuffed
FollowupID: 730171

Reply By: Whirlwinder - Monday, Jun 06, 2011 at 08:57

Monday, Jun 06, 2011 at 08:57
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.
AnswerID: 456540

Reply By: Member - John and Val - Monday, Jun 06, 2011 at 10:12

Monday, Jun 06, 2011 at 10:12

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.


J and V
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AnswerID: 456550

Follow Up By: KenInPerth - Monday, Jun 06, 2011 at 10:47

Monday, Jun 06, 2011 at 10:47
Hi J and V et all

Just throwing my bit in

A voltage reading at the fridge end with it running would also be helpful to see what voltage you are actually getting at the fridge end. If it is truly 4mm this may be the biggest problem assuming the batteries are in good condition.

If you have a lage difference between battery voltage and the fridge voltage with the fridge running then obviously it is cable (or bad joints) causing the problem.

If the battery terminal voltage drops significantly fridge off to fridge on then one would suggest the batteries are not good or not being re-charged.

I don't know a lot about the fridges but I believe they (newer ones ??) have a low voltage cut out on them so if the cable is undersized then maybe this is what is happening ??

As J and V state 4 and 6 B&S are very different to auto 4 and 6mm.

FollowupID: 729597

Reply By: MEMBER - Darian, SA - Monday, Jun 06, 2011 at 10:54

Monday, Jun 06, 2011 at 10:54
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).
AnswerID: 456557

Reply By: paulnsw - Monday, Jun 06, 2011 at 19:52

Monday, Jun 06, 2011 at 19:52
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.
AnswerID: 456634

Follow Up By: steved58 - Monday, Jun 06, 2011 at 20:54

Monday, Jun 06, 2011 at 20:54
I am no expert but run a 80L waeco with direct cable to one 100ah battery and have no problems in 30000kms of travel however it does get a charge at caravan parks and only ever has up to 15hrs max between runs It suits me and does not cost an arm and a leg purists need to get in the real world and have a look at what needs answered in the post most people I meet have very basic systems and are very happy with them I f the need to camp out for long periods of time then maybe there is a need for systems such as you speak of but as I said not for everybody
Cheers Steve
FollowupID: 729709

Reply By: Member - Robert R1 (SA) - Tuesday, Jun 07, 2011 at 00:14

Tuesday, Jun 07, 2011 at 00:14
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.


AnswerID: 456656

Reply By: Ian M7 - Tuesday, Jun 07, 2011 at 07:32

Tuesday, Jun 07, 2011 at 07:32
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
AnswerID: 456661

Follow Up By: Tonyfish#58 - Tuesday, Jun 07, 2011 at 18:56

Tuesday, Jun 07, 2011 at 18:56
Ian - You have my setup and I have had the exact issues and solved it this way to date. I was totally surprised that I could not get much more than a day and a half with the setup.

I also run the Waeco 80ltr. I have 2 x 105amp hr deep cycle Batteries.

I run a redarc from the main Battery with 6mm cable to a Anderson plug on the tray then to the batteries. There is no noticeable drop through the cable when the redarc activates - This will never full charge your batteries.

I run an 80w solar panel also. From research I have done this is about half of what you would need to run independent of a top up charge. I am thinking of getting a 120amp portable panel to give it a go.

Also connected into the system is a sidewinder 15amp smart charger. I use my ikva Yamaha inverter generator each night for a couple of hours to top the batteries up when I am not driving.

We occasionally pull in and use 240 if we are a bit slack.

The fridge is always using the 24v supply through the batteries (recommended way) and we just charge the batteries as noted above.

So the only fix was to add the smart charger and get access to 240 volts to make it work. You would have to get another 120w panel I would say and it would have to be portable so you can track it with the sun.

Regards Tony
FollowupID: 729807

Follow Up By: Tonyfish#58 - Tuesday, Jun 07, 2011 at 18:59

Tuesday, Jun 07, 2011 at 18:59
I forgot to add, keep the cables big & as short as possible. I was getting large drops between the batteries and the wacoe regulator and you get a noticeable drop from the regulator to the fridge.

Replace the original wires with a lot larger and use a multi meter to check your voltage drops between connections.

FollowupID: 729808

Follow Up By: Tonyfish#58 - Tuesday, Jun 07, 2011 at 19:04

Tuesday, Jun 07, 2011 at 19:04
Sorry :-) And another point - When travelling or on 240 charge always run it at max - When you pull up at night I turn it down to max 3 lights - It helps

FollowupID: 729810

Reply By: GimmeeIsolation - Tuesday, Jun 07, 2011 at 12:55

Tuesday, Jun 07, 2011 at 12:55
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.

AnswerID: 456683

Follow Up By: patrolmann - Tuesday, Jun 07, 2011 at 16:48

Tuesday, Jun 07, 2011 at 16:48
Hi totally agree with GimmeeIsolation,
I also have a late model waeco 80 and had endless trouble with it shutting down over night especially running at -10.
after speaking to endless guys one showed me what size cable he was running and he solved his problems.
So off to Jaycar and I bought I think it was 10ml cable, it has a red or brown see through outer covering and it was not cheap but worked well.
If I run my fridge on -10 it will run for around 18 hours not starting the car but i usually am on the move often or run it on 240 when and if I can.
A ctec or Redarc charger are also a good way to go. Alternators will not fully charge a battery in my opinion
FollowupID: 729791

Reply By: Member - Boobook - Tuesday, Jun 07, 2011 at 18:36

Tuesday, Jun 07, 2011 at 18:36
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.
AnswerID: 456710

Reply By: Ian M7 - Friday, Jun 10, 2011 at 08:31

Friday, Jun 10, 2011 at 08:31
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

AnswerID: 456949

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