Motorhome Upgrades – Batteries

We often see questions on Motorhome Forums about van upgrades, especially to do with batteries and getting more power during the winter months. So we thought we’d share what we’ve learnt and the upgrades we’ve applied to our van.

We collected our first motorhome, a Chausson Titanium 640, in March 2019. Following a fun summer of touring in ‘Lexi van’, we came home with a number of upgrade requirements to organise during the winter months. In today’s post Motorhome Upgrades – Batteries, Dave takes a closer look at van batteries and why you may want to consider upgrading yours.

Charging your batteries

If you’re going to live off grid sometimes in your van you need a way to charge your battery.  The two ways this is done are via solar and your alternator when your engine is running.  

However, it’s NOT very efficient or environmentally friendly to be sat idling for an hour, which we have seen campervans do!!! So Solar is your friend. The sun is free and can give you a decent charge in the summer, much less in the winter and nothing at night!

To capture the power of the sun you’ll need one or more solar panels. How much solar will depend on your power consumption and how much you move around.  When we bought our motorhome, as part of the purchase deal it included a 150w Solar panel, which the garage installed.

We have a 150w solar panel and to be fair, it served us well at a 5 day festival in mixed weather conditions.  The battery never fell below 50% without us being too careful – we still had coffee, toast, charged our devices and I think Miche might have used the hair dryer.  

We don’t tend to have lots of lights on at night, we like low ambient lights only for reading or watching movies on our iPad.  So that set up has been fine through our first summer with our motorhome. As the winter set in that’s when when the limitations began to show.  

In winter the sun is lower and your panels are flat on the roof, not angled, so they don’t get the best exposure.  In the summer I was seeing 5-7 Amps per hour, in the winter we were lucky to receive 1-2 Amps.  So it was enough for a trickle charge whilst the van was in storage, but we’d have needed more panels to do the same music festival in the winter.  

It’s on our list to get another 150W solar panel added at some point this year.  You can also buy solar arrays on Amazon that you just stand outside the van and angle up at the sun.  I’ve not gone down that route yet, as it’s something else to carry onboard and I’m not sure if they’d still be there if I left them out all day…:-)

As well as the solar panels you need a solar controller that connects the panel to the battery.  

There are two types of controller available:

• a PWM and
• a MPPT

Umm what?-ML –  Pulse Width Modulator & Maximum Power Point Tracking, clearer now?  Nope – ML. Me neither.  What you need to know is that the MPPT one is the better one.  If you want a little more info…

A PWM controller is in essence a switch that connects a solar panel(s) to a battery. The result is that the voltage of the panels will be pulled down to near that of the battery.

The MPPT controller is more sophisticated, and more expensive. it will adjust its input voltage to harvest the maximum power from the panels and then transform this power to supply the varying voltage requirement, of the battery plus load. You can run more panels and extract more usable power especially in cooler temperatures.  

We opted for a Votronic 1710 165W controller – I should have gone for a larger capacity one though (350W) as I now need to upgrade it or install another, to add a second panel. Doh!

Battery to Battery (B2B) Charger

Your van will come with some mechanism to charge your leisure battery on the move from the alternator.  In addition, modern vehicles have Smart Alternators that use the kinetic energy on braking and deceleration to charge the vehicle battery.  This reduces the need for the engine to power the alternator, improving economy and reducing emissions.  

To allow regenerative charging, the vehicle battery is held at a lower state of charge – if it was maintained at 100% by the engine charging, then there would be no space to consume a charge on braking.  This means that random bursts of high charge go into the vehicle battery and the amount that can be pulled by the leisure battery is lower and variable. 

The B2B charger smooths this out.  It’s totally configurable for the type of battery that’s donating and the battery that’s receiving. It therefore sends the optimum charge to the leisure battery ensuring that it charges faster but safely. Even on idle I see 30A going into the battery, there’s probably more when I’m driving – but I can’t see the monitor.  Thus, even a heavily depleted battery can be recharged in the couple of hours it takes to drive from A to B. 

I’m not an engineer, this is my layman interpretation of what’s going on based on what I’ve learned.  If you want the details then there’s some good resources below. I’d highly recommend this video, which demonstrates really well the before and after, note especially the impact of the fridge on the charging.

We have a Stirling 60A B2B charger fitted under the drivers seat next to the vehicle battery.  The leisure battery is under the passenger seat so cable lengths are low. They are also much more substantial than the standard cables, which allows the higher power and less loss.  In use, you can just hear the small cooling fan cutting in occasionally.  It’s about the same level as a computer cooling fan, if you have one in yours still.  It’s not really noticeable especially with road noise and the radio.  Not much else to say – it’s a fit and forget.  I’d definitely recommend it though, if you plan to be off grid a lot.

More info can be found here:

• Stirling PDF on Smart Alternators
• RoadPro installation of B2B charger battery before and after

Inverter

You need an inverter if you want to have 240v power away from an electric hook up.  The inverter converts 12v to 240v power.  As mentioned, 240v, will drain the battery quickly, so don’t expect to use it like you do at home (unless you invest in more batteries and solar).  But used carefully it’s perfectly possible to have the creature comforts from home.  We regularly use:

• Nespresso Essenza – coffee machine (It’s about 1200w) – 2 cups will use 3-5Ah. 
• GHD 150W Travel hair straighteners
• GHD 1200W travel hair dryer
• Low 800w Camping toaster – that actually makes really good toast – sourced from a camping shop

We also tried a small 3L Pressure King 3L pressure cooker. It worked fine, but takes a while to heat up and used a lot of power (as well as a lot of steam) so we’ve opted not to use it again in the van. 

When charging things, don’t use the 240v to charge if there’s another option, it’s very inefficient.  Often you can get a 12v cigarette lighter connection, which will use far less power (in converting up and back down) when charging your device. Use the 12v sockets, if you don’t have enough, get more installed.  Charge your devices as you go along from the cab too – that’ll use the vehicle battery.

The inverter we installed is a 1500W NDS.

Related Post:

Motorhome Upgrades – Understanding Electrics

In the next Motorhome Upgrade article Dave shares details about our amazing Audio Upgrade. More on that soon.

Finally, we hope this article, Motorhome Upgrades – Batteries has been useful to help you decide whether to upgrade your motorhome electrics.

NOTE: We are NOT experts, we are motorhome owners like you. We highly recommend talking to a specialist such as RoadPro (not affiliated with us), to identify the right set up for you.

Understanding our motorhome electrics and changing our motorhome batteries has given us more freedom when camping. It has allowed us to stopover in pub car parks, wildcamp on cliff tops, forests, lochs, next to the beach and more, without the need of a hook up. Definitely our most memorable and favourite camping nights have been “off grid”.

Want to read more articles like this one? Visit our Motorhome tips section.