Volvo C304/TGB 13 Expedition Camper

Volvo C304/TGB 13 Expedition Camper

About the blog:

Follow the transformation of a Volvo TGB 13 from cold-war-vehicle to all-terrain expedition style camper. The blog will be updated with our travel experiences from around the globe.

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The confusing batteries!

TechnicalPosted by raredog.dk Tue, January 26, 2016 15:39:05
Batteries are among the most confusing and strange things in the world! They belong right up there with questions regarding time travel, the hen & the egg and where the universe ends!

In the -15c Danish winter we discovered that our batteries weren't that great - Viola would start, but not exactly jumping like a cat.. The voltage was down to 12,2V when they were fully charged. As a former electrician, that seems okay on a 12v System, but no! It shows up that a fully charged battery should be 12,6-12,7V smiley
A 12V battery measuring 12V is considered nearly dead!

Not much else to do, than order new batteries... They are just under 3 years old, and with a 3 year warranty. So I called Tayna batteries in England, but they would not recognise it as under warranty without us shipping them back. As that would be rather expensive and we haven't much time we decided to buy new ones.

As an unexpected cost that feels like shaving some of our trip ofsmiley But the thought of the batteries giving up on us in the middle of Sahara was not that good either...

The old ones were Numax XV31MF, dual 110Ah leisure/starer batteries. After a whole lot of reading that don't make much sense, as a leisure battery would be build exact opposite of a starter battery.. (why didn't we read that 3 years ago?!)

A standard 110Ah wet battery will cope with around 50% discharges, more than that the lifetime will be heavily shortened. That means that for our two 110Ah connected in serial (24V) will have about 55Ah capacity, which again equals to about 37 hours running the fridge and nothing else.
That has, until now, been fine as we haven't stayed more that one night at a place.
But now that we will be on a 4 month trip, that might not be enough...

The solution ought to be simple: just buy batteries with more Amps?
Yes, but as it turns out, there is a great difference between wet, AGM and gel batteries. The gel ones are happy, even if the discharge is 80%. That means that a 80Ah gel battery will provide more Amps than a regular 110Ah wet... Confusing!

So we ended up buying two 80Ah Exide ES900 marine gel batteries, the should provide 900W, however that is calculated??! But that means that the fridge will run for 56 hours...


For starting we bought a Enduroline 100Ah AGM Starter battery. To ad further confusion there is also CCA (Cold Cranking Amps) MCA (Marine Cranking Amps) and a lot of other... Bigger and heavier seems to be good in the car battery world, and the new ones are bigger and heavier, so we cross our fingers and hope that they will do the job smiley





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The confusing batteries!

TechnicalPosted by raredog.dk Tue, January 26, 2016 15:39:04
Batteries are among the most confusing and strange things in the world! They belong right up there with questions regarding timetravel, the hen & the egg and where the universe ends!

In the -15c Danish winter we discovered that our batteries weren't that great - Viola would start, but not exactly jumping like a cat.. The voltage was down to 12,2V when they were fully charged. As a former electrician, that seems okay on a 12v System, but no! It shows up that a fully charged battery should be 12,6-12,7V smiley

Not much else to do, than order new batteries... They are just under 3 years old, and with a 3 year warranty.



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Larger fuel-tank

TechnicalPosted by raredog.dk Fri, August 22, 2014 10:30:44
Last year we had a lot of problems with the fuel tank. Some long-haired Swedish grunt had painted the inside(!) - probably to avoid corrosion when the Volvo wasn't in use.
But this paint gets loose over the years, causing the fuelline to get cloacked now and then, which then causes the engine to run very lean...

The paint is hard to remove and we always wanted a bigger tank, so a week before departure we took it of, did a lot of measuring and calculations and had a blacksmith make a new one.
The new tank holds about 110L and fits under the car as the old one.
The 110L is a calculation, we filled 128L in it, strange...

We couldn't decide if it should be made of aluminium, stainless or just normal steel - we ended out with the last one; it was cheaper, easier to repair if torn up - and as its always filled with diesel we presume it holds the rest of our time smiley

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Air Horn!

TechnicalPosted by raredog.dk Mon, April 21, 2014 19:52:43
Time to install a bigger horn!

The electrical one in front of the windscreen has a pretty pity, whimpy sound, so i asked a friend of mine who works at a truck garage if he could find something bigger and better.

He showed up with 4 massive air horns!!! :-D

Just installed 1 of them, a cheap 24v magnetic valve and a bit of hose and its working :-)
Mounted it under the car in the passanger side - it looked to strange on the roof and would probably be torn of by branches...

Under the car it is well protected as the car sits so high, and it is hidden from plain sight. It sound awesome with 15 bar pressure from the air compressor! :-D

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New batteries and wiring!

TechnicalPosted by raredog.dk Sat, March 30, 2013 09:20:50
The new batteries arrived!
The original wiring is intact, but all the extras (lights, fridge, water etc.) looked like a birds nest!
I marked all the wirings and disconnected them all, bought some new fuseboxes and began the looong assembly process...

The car is 24V, but the engine is 12V - and to make it all even more complicated we run a 24v/12v converter for radio and interior lights + a 230v converter!

The 2 old batteries for the 24v was getting tired and descided to replace all 3 with 110Ah Numax leisure/start batteries.


I put it all back together with proper markings, turned the main switch and nothing worked!!!!smiley

On the verge of crying!smiley i found out that i hadn't installed any fuses!
Unexpectedly it all worked when the fuses were installed and now its easy to see what the different wires are for and its easy to connect something new.
There is a lot of spare fuses for future projects smiley
Now i just need to make some kind of nice cover.

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12V charger/converter

TechnicalPosted by raredog.dk Fri, February 15, 2013 09:47:05

Finally got the 24/12V converter installed.

The output is 13,8V and up to 30A and it's connected via a relay to the ignition.

So when the ignition is on the 24V battery pack charges the 12V starter battery. When the ignition is off the battery doesn't get charged but the smaller converter still deliveres 12V for the stereo and interiorlights.

When used for long trips on a vaccation the old setup (24V converts to 230V which powers a smart charger that charges the 12V battery(!)) worked well, but we soon found out that we often forgot to turn on the charger and eventually this led to a flat starter battery. On the other hand: when we remembered to turn it on, we'd often forget to turn it of again, which then led to a flat 24V battery pack...

This way we don't have to remember anything and it also much more effective without triple-converting smiley

As these old army-vehicles is 24V and most dieselengine conversions are 12V there is a lot of talk about what to do. Some chooses to convert it all to 12V, but in my opinion its not the cleverest thing to do. All wires would in theori had to be the double size and then you'd have to change both wiper motors, both ventilation motors, the sprinkler motor, all the gauges and all the bulps... Another option with the OM603 engine would be to convert this to 24V. This engine is available in a marine version and therefore 24V starter and glow plugs are available. But these are expensive and i would think it is much easier to find 12V spare parts around the globe...

Therefore we ended up with this solution smiley

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DC-DC Converter/Charger

TechnicalPosted by raredog.dk Tue, December 04, 2012 12:47:35

Just got this Converter, its a 30A 24-12V, but unlike most dc converters the output is 13,8V and can therefore be used as a charger.

Right now the car runs on 24v (old military truck, remember?) but the engine runs on 12v. The alternator charges the 24v battery pack and a 230v AC converter powers a smart charger used to charge the 12v starterbattery. This is a strange mess from my point of view and requires that you remember to turn on the charger (and turn it off when you stops) The 24v battery pack also runs a 12A/12V converter which powers the radio, internal lights etc.

Now the charger gets replaced by this, charging the 12v battery when driving.
Don't know yet if its also going to replace the smaller converter, but it might be better running both as we then have 12v when the engine is off, without any needs for relays and switches.

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Voltmeters installed

TechnicalPosted by raredog.dk Mon, November 26, 2012 09:36:07
Got the voltmeters installed last night.
Unfortunately there wasn't enough space available in the stereomount under the roof, it would have looked great there.

Instead i installed it on the dash. The voltmeters a some cheap chinese ones from dealextreme, and they didn't meassure exact the same voltage - about 0,5 V off... Hmm... Found out that there was an adjustment screw on the backside, so it was fairly easy to calibrate them to a real voltmeter.
Its not that important that they meassure it 100% correct - its just to see if they are charged correct and the batteries are ok.

As the starter battery is 12V and the leisure batteries are 2x12=24V i installed 2, they switch on with the ignition.
Might install another 2 at the rear so that vi can monitor it from the camper part aswell.

While waiting for the new DC30 24-12v inverter to arrive we went on a small camping trip in the woods :-)
A bit cold as we haven't installed a heater yet, but as long as we kept all bodyparts under the duvet it was okay :-)
The white LEDs are great for orientation in the camper, but its a lot more cosy with the warm white reading spots on and the curtains down :-)

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