CHARGING HOUSE BATTERIES

[part time nomad]

What is the best way to charge my house batteries?

The vehicle runs a 24 volt system, but the camper side requires 12 volt

Option 1: run a battery to battery charger 24v to 12v .....step charging but limited Amps available.

Option 2: battery to battery 24v to 24v, higher amps but will require power consuming 24 to 12 dropper.

Option 3: fit extra 12volt alternator to charge 12volt batteries.

Option 4: fit extra 24volt alternator and 24 to 12 dropper.

I would be interested to see what the pros and cons are from experience

My truck is a Mercedes Vario 4x4

 

[Joe917]

My truck is 24volt and the house is 12volt.
My system: Sterling battery to battery charger, works great but almost never used.
Magnum 2700watt inverter/ 125amp charger, used to invert several times a day but almost never to charge.
4000 watt generator almost never used.

Morningstar 60 amp MPPT charge controller with 630 watts solar on the roof. This does all our house battery charging.
Trimetric battery monitor. A battery monitor is essential. A voltmeter IS NOT a battery monitor.
We have been traveling full time for over a year and have only twice gone more than 4 days without reaching full charge, we normally hit 100% charge every day.

In short load up on solar and get the Sterling battery to battery charger as back up. Best price was custom ordered from Defender Marine(far simpler and cheaper than a second alternator).

 

[IdaSHO]

What is the best way to charge my house batteries?

The vehicle runs a 24 volt system, but the camper side requires 12 volt

Option 1: run a battery to battery charger 24v to 12v .....step charging but limited Amps available.

Option 2: battery to battery 24v to 24v, higher amps but will require power consuming 24 to 12 dropper.

Option 3: fit extra 12volt alternator to charge 12volt batteries.

Option 4: fit extra 24volt alternator and 24 to 12 dropper.

I would be interested to see what the pros and cons are from experience

My truck is a Mercedes Vario 4x4

Ill add option #5

split-charge relay + MPPT charger controller.

Feed the MPPT charge controller 24V and configure it to to correctly charge your 12v house bank.

 

[Joe917]

Ill add option #5

split-charge relay + MPPT charger controller.

Feed the MPPT charge controller 24V and configure it to to correctly charge your 12v house bank.

Keep it simple. Solar to house batteries only. There should be no reason to run solar to the vehicle. Keep them separate.

 

[IdaSHO]

I made no mention of solar.

For a reason.


But that doesnt mean you cannot add solar, and use the same charge controller.

 

[part time nomad]

Thanks for all the replies.

Ha Ha ! Verkstad I like that, it does seem that sunshine is illegal in the UK sometimes!

I forgot to mention that I will be using solar power, as in my opinion, it gets up and starts before I do! and it carries on silently all day. perfect! Although it does have its draw backs, as in the winter months with little sunshine, but you end up spending more time in the vehicle using power than can be supplied, so I am looking at alternative systems,
I have a 1kva Honda generator as a last resort back up! that I can use for charging ect, but on the whole I hate generators as they are noisy unsociable things.

I have about 380watts of solar panel to put on the roof, but this may struggle to keep up in the winter, especially as I have a compressor fridge freezer,

I quite fancy the EZA LIFeP04 battery pack from www.roadpro.co.uk but its costly.

 

[julius0377]

Option 1: run a battery to battery charger 24v to 12v .....step charging but limited Amps available.

I have one of these in my Atego: http://www.votronic.de/index.php/en/products2/series-vcc/standard-version/vcc-2412-45

Charges to full capacity with any medium to long drive. Stable and reliable.

 

[Gretar]

For my Vario I bought 24-12 battery charger from Euro Manufacturing and Marketing ltd, Shropshire, England www.eurogroup.gb.com
E1076 30 amp charger. Works well.

 

[ianc]

Additional 12V alternator + "Smart" controller from Sterling or equivalent

 

[Sitec]

I like the idea of a separate 12 volt alternator, charging 2 12 volt batteries. Separate system, but with a couple of relays allowing it to be excited and initiated by the 24v system. You'd have a second charge light on the dash too.. Fixable on the side of the road, and all parts are available worldwide. House batteries go flat and the vehicle still starts. Vehicle batteries go flat and you at least have a pair of charged batteries that can be borrowed to get you out of trouble.

 

[nick disjunkt]

I have a 24v house battery in my truck and use 24v for almost everything. I have a small Victron 24v to 12v dropper which is left permanently on to run the toilet flush valve, the hifi cross-over processor and the pair of cigarette lighter sockets that I use for charging consumer electronic devices. This works well for me, although it is fair to say that your choice in some devices is limited if you try to stick with 24v.

I have a sterling battery to battery charger but I have been thinking about removing it at some point. My alternator is 100a at 28v and the Sterling is limited to 30a. I can't be sure but I'd be pretty confident that I'd charge my batteries quicker when I need it most with 100a, albeit at a fixed voltage, rather than 30a with a 3-step charging system.

I have an 800w solar system which is great in southern latitudes, but is all but useless in a British winter. England is pretty far north and in winter, with the panels mounted flat on the roof, I can rarely even keep the fridge from running the batteries down.

I like the second alternator idea too, but there is a lot to be said for keeping the engine and drivetrain stock, so that you can order replacement parts from the VIN. If you change the belt length, you will need to remember that every time you get a pack of service parts from the dealer.

 

[part time nomad]

Ianc,
Did you fit an extra pulley to the crankshaft? if so I don`t suppose you have the part number?

 

[ianc]

I didn't need to. I just added an extra tension pulley and mounted the Alternator. There is a diagram somewhere in this forum which I posted and shows how. I pull up to 180Amps with this setup (charging batteries plus running 220v A/C via an inverter).

I think you would only need the second pulley if you were also using A/C.

 

[IdaSHO]

My brain is having trouble sorting this dual alternators at different voltages.

The second (12V) alternator will need to have an isolated ground as well, right?

 

[IdaSHO]

Hey, my old Subaru is wired with switched grounds.

Never know :coffeedrink: