Skip to main content

As many VW Grand California owners know, the standard van is not great off grid. With a single 100AH battery under the bonnet, your Grand California will get 24 hours usage from the battery if you are only using the fridge. If you decide to turn on a light, or heating this time will be reduced further.

There are many ways to extend the period you can spend off grid. The easiest and most cost effective option is to replace the battery under the bonnet with a lithium battery. Lithium Pro make a 150AH battery that is the same size as Grand California’s the standard battery. With a lead battery you have a 50% draw down, this means that if you have a 100AH battery, you have 50 usable amps. A lithium battery has 100% draw down, so with a 150AH lithium battery, you have 150 amps. So using a battery with the same dimensions as the original, you triple your time off grid.

The lithium battery will work as a direct replacement, but if you simply swopped the batteries you would be missing out on many of the advantages of lithium. You can safely charge a lead battery at 10% of the AH size, so with a 100AH lead battery you can charge it at 10 amps. This is why your split charge is small, and your 25 amp mains charger can barley cope with replenishing the loads while using the Grand California, let alone charging the battery. So the problem compounds itself, when you are travelling (unless it is a 10 hour journey) your battery will get minimum charge. The battery will already be discharged as you cooled your fridge down before you left and left it running the entire journey. When you arrive at your destination, your battery will be not be full, so you will be lucky if it lasts a day.

In conjunction with a Lithium battery, we always recommend upgrading your split charge. Good quality lithium batteries will allow a C-1 charge, so a 100ah battery can be continually charged a 100 amps, so an 100AH battery can be charged in an hour of driving. Most battery manufacturers recommend a C-0.5 charge, so with a 100AH lithium battery you could upgrade your charging to 50 amps, this would charge a fully discharged battery in 2 hours. So it you had a 150ah lithium battery, it would offer 3 times the usable power as the standard battery, if you then upgraded the split charge to a 50amp system, you can run your fridge while driving and still have a 40 -45 amp charge going into your battery. When you arrive on site you will have a cold fridge and a fully charged battery.

If you add solar to the equation, your situation will improve further. Lithium batteries have less resistance than lead battery, so they are easier to charge, solar loves lithium. I have been fitting solar panels to motorhomes and camper vans for many years, and simply sticking a 100w panel on the roof through a cheap Chinese solar regulator is not the way, but this would reflect most of the solar systems installed on motorhomes and camper vans, this is because it is cheap, quick and easy. I do it differently. Solar panels are normally produced using one of two voltage ranges, 20-23v for small panels and 36-48v for bigger panels. To supply a charge voltage to a battery the panel needs to be producing between 13.2 and 14.4v, with a 20v panel this will only happen when there is plenty of light, so between 10am and 3pm in the summer and possibly for an hour in the winter. This is why the small systems are so ineffective. What we have found following years of experience, is if you take 2 x 50w panels and connect them in series, so increasing the voltage to 40v you will almost double your yield. We carry out large solar arrays on motorhomes and camper vans, for example I can fit 300w of solar on a Grand California 680 using 8 panels, I can fit 480w on the new Adria Twin using 12 panels, this system can see voltages greater than 120v DC from the roof, supplying an amazing yield. We have recently installed 935w on a Hymer A class using 11 panels.

The pictures above show a recent upgrade carried out on a Grand California 600. The upgrade included a Victron Phoenix Smart inverter connected to the AC system using a mains priority switch, this allowed all the sockets to be powered when you were not plugged into a mains supply

We upgraded the split charge using a 90 amp Votronic unit. This would provide a charge current of 90 amps into the battery, even when the engine was on tick over

The power storage was supplied using a Fogstar 560AH lithium battery, all the equipment fitted in the 2 rear cupboards, the cupboard with the battery is now a bit smaller, but still allows for plenty of storage.

If you would like to see the system we installed into a Grand California 680, please click on the link

Leave a Reply