I bought a 12 year old Autotrail Cheyenne Motorhome in 2020. It was in great condition, but the electrics would have been regarded as a little dated even in 2008. The following series of posts discussed the various upgrades carried out. Some of the changes mentioned I later changed further in fact, so this is pretty much a Journel of Adaption
Introduction
I bought an used Autotrail Cheyenne Motorhome and one of the things I always intended to do was update and improve the Habitation Electrics.
I knew no factory-made Motorhome would provide what I wanted, so no matter what I bought, I’d need to update, and the general other features of the Cheyenne were just right for our needs, so a perfect base for upgrading.
This will be a multi-part post, and the first part is to scope out the target plan
Part One. What is fitted and what the general target is?
What’s Fitted?
The Autotrail Cheyenne is a fairly high-end Motorhome and is fitted with some reasonable if somewhat dated Electrics.
It has a Sargent EC325 Power Distribution which is a fairly nice unit with integrated 12V fusebox and wiring, plus a 240V integrated Consumer Unit with 3 MCB circuits. This unit also has a comprehensive control panel with tank info, switchable selection between Leisure and Vehicle batteries and a Charger that operates both on Hookup and Alternator. This is a handy Multi-stage charger that works on both Alternator and Hookup and genuinely does go into a Bulk and Absorption mode at ‘proper’ voltage levels before settling into a Float mode
The downside of this unit is the very limited capacity of the charger, maxing out at under 10A charge rate when either Driving or on EHU.
Fitted to the Cheyenne was a pair of 100Ah AGM Batteries, which sound ok but actually were worn out and in desperate need of replacement.
The previous owner, who had the Motorhome from new, never fitted any roof-mounted Solar but carried a portable panel.
There was no off-grid 240V available. That’s pretty typical for a Motorhome of course, but I wanted to be able to use 240V at any time, so an Inverter would be needed. This would be for convenience things like Laptop Chargers, Microwave, Slow Cooker, small Induction Hob, and the like.
Needed? No. But these are things that are good to have access to when you want them IMO.
I also want a reasonable length of time to be able to be off-grid/wild camping, so a decent sized Battery Bank is needed and of course depending on the time wanted to spend off-grid will factor into the amount I use the Inverter and when needed simply revert to other options to the electric cooking tools to extend that time. But if power is there, use it and save gas
Flexibility is the name of the game
So the target…
First was choosing the new batteries to replace the pair of AGMs. Originally I was looking at Lithiums (and specifially the very attractive Poweroad Infinity LiFePO4 models) but for the capacity I wanted and the other items I needed to get, they were above the available budget, so I instead selected the Ritar (Expedition) Lead-Carbon 100Ah Batteries. These batteries, again from Alpha Batteries, are an excellent battery with very usuable capacity and high charge-cycle count and under a 1/3rd the price of even the well priced Infinitys ;).
So into the Motorhome went 3 x 100Ah Lead-Carbons, offering a perfectly usable >240Ah capacity but stil retaining a better cycle count then simple AGMs taken down to only 50% DoD for example. As a trade partner of Alpha-Batteries, I was able to secure these batteries with a discount but that did not influence my selection, having had excellent experience of a different brand Lead-Carbon Battery Bank in my Campervan
To provide EHU Charging Service and Inverter, I chose a Victron EasyPlus 12/1600/70. This incorporates a 1300W Inverter (so covers all the 240V products I might want to use) with a 70A Charger (The bank of 3 batteries can charge at a rate of 30A/Battery, so a 70A charger is a nice match for the bank). The EasyPlus is a combination of a MultiPlus 1600 with a 240V AC Distribution Setup built into it. There would seem to be a degree of duplication with the Sargent, but in fact this extra feature in the EasyPlus compliments it well, allowing extra features and flexibility (to be covered later) to be incorporated into the build and for some strange reason can be sourced at a lower price than the straight Multiplus 12/1600/70 .
The EasyPlus Charger takes the over the function of the Sargent EHU Charger, and so giving a charge rate of upto 70A rather than the original 10A – a massive advantage of course. I decided to marry a Battery to Battery (B2B) unit to that to take the place of the Sargent Split-Charge unit, and chose the Ablemail AMC 12-12-60 60A Battery to Battery Charger. This is a perfect companion to the Multiplus and a great match to the Ritar Batteries.
Whilst I would have chosen this B2B for my installation anyway, having had excellent results from its smaller 30A brother on other installs, for this installation I was fortunate to be gifted this unit by Merlin Electronics, producers of the Ablemail products.
For Solar Charging, I will have a PV Array permanently mounted on the Roof, going down to a Victron SmartSolar MPPT 100/20 Controller. This controller is good for upto 290W of PV and the plan is to have 270W on the roof, so a perfect match (and as it happens, a Controller I happen to have kicking around, which is very handy)
To complete the picture in terms of components, I will be adding a Victron Cerbo GX ‘communication centre’ that the EasyPlus, SmartSolar and a BMV-712 Battery Monitor will connect to to collate the data from all the units and feed the Victron Remote Management Portal as well as allowing remote monitoring AND remote control of the electrics in the Motorhome.
So this is the Goal and will give my Cheyenne Motorhome a very good level of extra flexibility and usability.
Adding the kit above is pretty easy. Doing it neatly in a such a way to not stand out like a sore thumb in the traditional appearance of the Motorhome interior (and I do find the interior design of the Cheyenne very attractive in fact and don’t want to mess with that in a ‘unsympathetic’ way) is another matter and the install will be the next stage.