Charging the power station through the car battery

[Jarf]

Can I connect a power station (Delta 2 or 3) directly to the built-in living room battery (95Ah) to get it charged while driving?

Or do I still need an alternator?
And if so, can the alternator then be connected to the cable that comes from the car battery going to the living room battery and from the alternator have one connection to the living room battery and the other to the power station. Or is there another way of using the already drawn cable from the car battery to the living room battery?

I also found guides on YouTube for an alternative option of using a Victron Energy Orion 12/24-Volt 20 amp DC-DC Converter to fool the power station to believe the charging is coming from a solar panel. Can this solution be mounted to the PS directly from the living room battery?

My van is a Karmann Davis 620 Lifestyle, 2023.

 

[Langtoftlad]

Three ways of charging a Powerbank [eg the Ecoflow Delta 2/3]
Mains 240v - very quick, about an hour for a full charge
Solar - most have an integrated MPPT controller. Speed of charge depends on amount of sun & size of panel
12v car socket - very slow, about 10-12h for a full charge

*AFAIK Ecoflow have an optional accessory that you wire into your vehicle's alternator. Should charge your unit in about 1-2hrs driving [but it's expensive]

 

[Landy Andy]

You can charge it via a 12v power socket and you can adjust the power it takes. But it takes ages, and your wiring (vehicle) can get HOT.
The EcoFlow alternator is far better, safer, quicker, but costly.

 

[Cush]

Bluetti charger 1? Charges from alternator (vehicle battery) at about 560 watts / hr. Slower but cheaper than the eco for 800. Not quite sure why you’d want to charge from the leisure battery? It would need to be replenished too. You can use the 12 v cigarette socket on the hab or vehicle side. But slow.

 

[Jarf]

Bluetti charger 1? Charges from alternator (vehicle battery) at about 560 watts / hr. Slower but cheaper than the eco for 800. Not quite sure why you’d want to charge from the leisure battery? It would need to be replenished too. You can use the 12 v cigarette socket on the hab or vehicle side. But slow.

Only a 25 euro difference between the two.
I want to charge from the cable that charges the leisure battery, want to charge them both from that same cable. That way I don't have to pick apart the whole car to get cable drawn from the engine room back to the cars living room since it's all already been done for the leisure battery in factory.

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[Jarf]

Seems no one know enough about batteries in cars/camper vans anywhere on any forums to help me with this.
Anyone knows where I can find people with this knowledge?

 

[chaser]

We charge ours through the fag lighter when moving and solar from the hab battery when parked.

 

[Langtoftlad]

I think you've been given the answers .
The Ecoflow won't accept the charge from the alternator to hab battery if you split that cable without the previously mentioned accessory.

 

[Cush]

The cabling in the van may not be capable of doing both leisure and PB at the same time on the same wire. The cigarette lighter socket is a good suggestion if you have them. Taking cable from engine bay to living side is not a big job. Normally holes that will let you do it.

 

[gus-lopez]

living room battery (95Ah) to get it charged while driving?

Yes.

(Delta 2 or 3) directly to the built-in living rroom

The delta3 pro has two input sockets .the first for direct solar ,check the amount you can input, and the second for any input up to 60volts,check voltage on your unit. This could be used for a 12v+ supply from cig socket or direct from alternator as long as it cannot go above the max voltage. On mine I input 51,2volts from a pair of batteries.

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[autorouter]

The basic problem is that the charging power along 12V cables is limited by the thickness of the cable. From a cigarette-lighter socket you can't get more than about 10 amps, which at 12 volts will give you a charging power of 10 x 12 = 120 watts. To charge a flat 1024 watt-hour power pack, that's going to take about 1024 / 120 = 8.5 hours.

The living room battery gets more than this by connecting directly to the engine alternator while the engine is running. That's done with a split charge relay. That will give you about 20 amps or so, which is about 20 x 12 = 240 watts. That's still not very much power. Even if you could get all that into your power pack, it would take a few hours to fill it.

These two methods rely on the direct output of the engine alternator, which is not an ideal source for charging a lithium battery pack.

A better approach is to use a DC-DC charger, connected to the engine alternator/starter battery. This is an electronic device that takes power from the engine alternator in exactly the same way that the vehicle lights, wipers and fans do. It then outputs that power with a voltage exactly tuned to charge the battery at the optimum rate, and shut off when it is full.

The 'alternator' gizmo that you mentioned, from Ecoflow, is a DC-DC charger, with an output designed for their power pack. It will take power from the engine alternator/starter battery when the engine is running, and shut off when the engine stops. It will push about 800 watts into the power pack.

Because it is pushing out 800 watts, it will require about 800 / 12 = 67 amps from the engine alternator. Obviously you can't plug that into a cigarette-lighter socket that can only provide 10 amps. That's why it needs to be wired back to the starter battery with thick wire that can take 70 amps. There is a already substantial wire from the engine alternator to the starter battery, so no need to upgrade that bit.

As an alternative, you suggested using a Victron DC-DC 12V-24V Converter, which will output 24V at 15A, which is 24 x 15 = 360W. That's better than the miserable 120W you can get from the cigarette-lighter socket. Note that for a motorhome or camper, the isolated or non-isolated versions are both fine. The non-isolated version is a bit cheaper when new, but a used item of either type will be fine if you can get it cheaper. Don't confuse a DC-DC Converter with a DC-DC Charger, they look very similar and are on the same page on the Victron website.

Victron do higher power DC-DC Converters than this. But there is a 15A limit on the solar charging input, so those would be no good for this input method.

But all of them would require a wire of suitable thickness back to the starter battery terminal.

 

[Jarf]

The cabling in the van may not be capable of doing both leisure and PB at the same time on the same wire. The cigarette lighter socket is a good suggestion if you have them. Taking cable from engine bay to living side is not a big job. Normally holes that will let you do it.

Thank you
That's one of the answers I needed, to know that the cable may not be good enough for both systems to charge. I know about the cig socket supply, but that will take 10 to 20 hour driving. I don't drive those distances in one day.
Cabling in this car, Fiat Ducato, is, to me, a big job. It is very tight in the engine room. I would have to take apart parts of the car to get to the car battery and other parts. To me that is a lot of job. Old cars I can work with, plenty of space and easy access.

 

[Landy Andy]

Thank you
That's one of the answers I needed, to know that the cable may not be good enough for both systems to charge. I know about the cig socket supply, but that will take 10 to 20 hour driving. I don't drive those distances in one day.
Cabling in this car, Fiat Ducato, is, to me, a big job. It is very tight in the engine room. I would have to take apart parts of the car to get to the car battery and other parts. To me that is a lot of job. Old cars I can work with, plenty of space and easy access

Eco flow alternator is one wire to battery positive and one wire to battery negative, the battery is under the cab floor not with the engine, and it’s not a car.

 

[bigtwin]

and it’s not a car.

In some countries, most notably France, it is a car (vis-á-vis, a camping car).

Ian

 

[Ian_H]

MIne is an Anker Solis rather than an Ecoflow. I made a switched and fused connection from the lithium leisure battery that plugs in to the Anker solar socket. It only charges at 10A (limited by the Anker) but thats fine overnight. I don't trust the van lighter socket wiring (edit: or the hab 12V wiring) to cope with 10A over a long period. The leisure battery is charged by solar or b2b.

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[CAB96]

Eco flow alternator is one wire to battery positive and one wire to battery negative, the battery is under the cab floor not with the engine, and it’s not a car.

I'm guessing Jarf is Swedish?

Jarf we would call it a Van.