Lithium upgrade Coachman Pastiche 2017

[sah0666]

I've just sold my Renault Master campervan and bought a Coachman Pastiche 2017.

I had previously upgraded the camper with an EcoWorthy 100Ah lithium battery, supported by Vitron: AC-DC, DC-DC, and 75/15 MPPT solar chargers, plus a Renogy shunt.

I'd like to try similar with the caravan since we often do 4-5 days off grid and need to be able to use our "Reich Easydriver Basic" motormover on our return.

There's a bit of a slope on my drive and the motormover is already struggling.

I currently have a 105Ah lead battery, the standard Coachman charger and a Solar Technology 10A PWM Dual Battery Charge Controller.

I'd thought to change to a 150-200Ah lithium battery which will fit in the battery compartment.

I've already ordered a Vitron MPPT 100/20 - SmartSolar Charge Controller and 500A shunt since these will improve things anyway and are simple to fit. But what next?

I’m unsure whether the current AC-DC charger will be OK with Lithium battery and since my car has a smart alternator need to think about the DC-DC charging issues.

Should I spend more on a battery with BMS or change the AC-DC charger.

Can I fit a DC-DC charger by attaching it to the permanent 12v live from pin9 of the trailer plug?

I’d be grateful for your advice.

 

[GUMPY]

I’m unsure whether the current AC-DC charger will be OK with Lithium battery and since my car has a smart alternator need to think about the DC-DC charging issues.

Not necessarily
The smart alternator on my Skoda is made non smart as soon as you connect the caravan.
It delivers 14.2v at 5 amps to my Fogstar.
Charges it fine. It's only on long journeys, 200+ miles, that the battery BMS shuts down which is not a problem for the alternator or the battery.

 

[sah0666]

Not necessarily
The smart alternator on my Skoda is made non smart as soon as you connect the caravan.
It delivers 14.2v at 5 amps to my Fogstar.
Charges it fine. It's only on long journeys, 200+ miles, that the battery BMS shuts down which is not a problem for the alternator or the battery.

So the answer is probably buy a battery with a good BMS and forget the charger change.

 

[GUMPY]

So the answer is probably buy a battery with a good BMS and forget the charger change.

Only if the voltage is within specified limits of the battery.
I was quite prepared to add a B2B charger but tested it first. In two years the BMS has only shut charging down once and given a few high volts alarms.
I normally wouldn't rely only on the BMS but this is within its parameters.