Sense check on proposed upgrades

[GMLS]

Would welcome your endorsement or otherwise on my plans for accessories to be fitted to our new A class Rapido 854F. We will be doing a lot of off grid camping.

1) It comes with 2x100ah leisure batteries but no solar so thinking of installing something like 300w panel(s) with a Victron MPPT controller (I like the bluetooth functionality). Will consider lithium upgrades once those batteries are past their useful life.
2) I plan on getting the MPPT connected to both the leisure and starter batteries as I don't want to rely on having the hook up connected whilst stored at home so the solar will top up the starter battery in most conditions. In the past I've had the little Vanbiz B2B to keep the starter battery topped up but understand linking up the solar to both pretty well negates the need for this?
3) Based on the above, I was then thinking of installing a Victron B2B as I understand the new Ducato's have smart alternators so will kick out plenty of power to charge up the lead batteries in between stops but also in the future allow me to get the best out of lithium.

Is my strategy sound ?

 

[the1andonly]

I was under the impression that victron controllers only connected to one battery at a time apart from expensive multi bits and pieces any specific part number. The duo votronics models do have the ability to trickle charge a SB and can deal with lead or lithium batteries. I use The later . Bluetooth capability can be added to the votronics stuff.

 

[Jimbohorlicks]

If you have a smart alternator why will you require a b2 b for lead batteries ?

 

[autorouter]

2) I plan on getting the MPPT connected to both the leisure and starter batteries as I don't want to rely on having the hook up connected whilst stored at home so the solar will top up the starter battery in most conditions. In the past I've had the little Vanbiz B2B to keep the starter battery topped up but understand linking up the solar to both pretty well negates the need for this?

Can you clarify 'in the past'? Is the VanBitz BatteryMaster fitted to this MH or one you previously owned? If it's this MH, then there's no need for a dual output solar controller. The BatteryMaster will take care of the starter battery if the leisure battery is charged by solar or hookup. If you don't have a BatteryMaster then a dual output solar controller will charge the starter battery when solar is available. It won't charge the starter battery when on hookup and there's no sunshine, but many people don't find that's a problem.

As Jimbohorlicks says, if your MH has a smart alternator it very likely has a B2B already fitted.

 

[Marauder]

I have been thinking along these lines,
but several MHF advised that I should drive it at least every 3/4 weeks anyway for other reasons mentioned elsewhere on this forum.

So I'm now thinking " if I will be driving it regularly, why worry about battery charge rates at all ? "

???

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[GMLS]

Can you clarify 'in the past'? Is the VanBitz BatteryMaster fitted to this MH or one you previously owned? If it's this MH, then there's no need for a dual output solar controller. The BatteryMaster will take care of the starter battery if the leisure battery is charged by solar or hookup. If you don't have a BatteryMaster then a dual output solar controller will charge the starter battery when solar is available. It won't charge the starter battery when on hookup and there's no sunshine, but many people don't find that's a problem.

As Jimbohorlicks says, if your MH has a smart alternator it very likely has a B2B already fitted.

We had a Batterymaster fitted to a previous motorhome we had and it worked a treat but as you say, I don't think we will need one as the Rapido's electronics (which I think is a CBE system) probably will have one

 

[funflair]

If you have a smart alternator why will you require a b2 b for lead batteries ?

Because Smart alternators aren't really that smart, they are set up as standard to charge the starter battery of the van chassis and know nothing about the habitation batteries so the alternator will only be working when you are off the throttle so essentially it is using free energy, I should add that some converters re-programme the Smart alternator to run all the time.

 

[funflair]

We had a Batterymaster fitted to a previous motorhome we had and it worked a treat but as you say, I don't think we will need one as the Rapido's electronics (which I think is a CBE system)

CBE CSB2 most likely actually work differently to VB Battery Master as the CBE needs something like 13.6v to trigger the link to the starter battery and 13.6v would only be available with hook up or solar, for example our Flair which had the CBE CSB2 and a VB battery master lived in a shed and never saw 13.6v once it was parked up as we had no hook up, the VB battery master works on a differential in voltage of something like 0.65v so when the starter drops 0.65v below the habitation it puts some charge in and eventually it pulled the habitation batteries down to a point that the EFOY started automatically and everything was charged again.

If you have solar or hook up holding your habitation batteries over 13.6v you will be OK with the CBE CSB2.

 

[GMLS]

Update
So with the price of lithium batteries falling and having an alternative use for the 2x lead acid batteries that will come with the van, I'm now thinking of getting lithium fitted immediately.
So having looked at Will Prowse's excellent website and Youtube channel and a few other resources. My current thoughts are;

Fit 350w - 400w of solar power in series
Fit 2x 100ah or 1x 200ah Renogy lithium batteries to replace the lead (these are mounted at the back of the van, internally)
Fit Renogy DC to DC charger 50 amp with MPPT
Fit Renogy BT-2 bluetooth adapter for display free monitoring
I don't need an inverter, certainly for now
I understand the on board charger will stay connected for charging all batteries if we are on extended hook up say in winter?

When driving, as the charger will allow upto 25amp from the solar and upto 25amp from the alternator to go into the batteries, as the input from the solar will be less than 25amp, it seems to make sense to include an isolator switch to cut out the supply from the solar so I can get a full 50amp from the alternator into the batteries while driving?

I'm still waiting for confirmation of whether the supplied onboard charger will be able to optimise charging of lithium when driving but does the above look like to optimal solution or if the on board charger can fast charger lithium via the alternator, am I better off just fitting something like a Victron MPPT to manage the solar?

 

[SeanF1]

Hi there. I have just fitted this unit (see separate post). It has a max PV input limit of 25.5 volts so you will not be able to connect the panels in series, but in parallel will work fine.

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