Keep 24volt cab battery topped up.

[Mike001]

hi folks,

So my motorhome is a 2004 Mitsubishi Canter, 24 volt system for the cab.
I am thinking, that to make sure the cabbattery is kept "optimal" to do the following:

Buck booster from 12volt lithium set to say 27volts output, feed this into a spare PWM solar controller that I have laying around which would keep the 24 volt battery topped up.

Any thoughts?

 

[Guigsy]

Have you considered having everything on 24v? It means smaller cables and better efficiency. There are plenty of 24v systems out there.

 

[Mike001]

I have considered that option but am now firmly entrenched in the 12 volt hab side.
Recently (within the past year or so) upgraded cabling, invertor, Lithium battery, charging etc

Just want to ensure I keep the 24 volt cab side "up to scratch"

 

[TheCaller]

You can get a 12 - 24v Victron Orion-Tr Smart DC-DC charger. I'll have a nearly new one going cheap as soon as Victron release the new XS variant in 12 - 24v configuration.

 

[Mike001]

Thanks for the offer but I think it would be a wee bit expensive to send to New Zealand.

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[Googlebot]

Doesn’t jongood have a 24v cab setup? They may be able to help?

 

[jongood]

I have considered that option but am now firmly entrenched in the 12 volt hab side.
Recently (within the past year or so) upgraded cabling, invertor, Lithium battery, charging etc

Just want to ensure I keep the 24 volt cab side "up to scratch"

Hi, I have a similar setup, 24v on chassis side, 12v hab. initially I was concerned so bought and fitted a 12v to 24v maintainer from Sterling, it worked well but is not suitable for use with Lithium, so when I introduced 1x LifePo4 into the hab side I disconnected it and tbf I very rarely plug in and haven't missed it. My chassis batteries (2x 110ah SLA) are at least 5 years old but in OK condition (ASFAIK). My theory is that at 24v there is a bit more tolerance for the starter motor??

If its causing you concern what about getting a separate small panel to keep the 24v side up, the kit is out there and not that expensive.

I too wondered about going 24v hab and then stepping down for the bits that were easier at 12v but like you I also sorted the house side out before the penny dropped so have a load of stuff setup at 12v that works too well to think about junking it.

When we visited NZ we rented a Mh very similar to the one in your avatar ( from share a camper so it had the wings). I keep telling the guys on here how good the NZMCA scheme is for freedom camping, public dump stations and the "self-contained vehicle" scheme but we are stuck with the crappy caravan club that just wants to flog pitches.

 

[Mike001]

Hi jongood,

Good comments... thank-you.
I haven't had any issues as yet with the starter batteries... truck can be sitting for 4 to 6 weeks without moving but I do start it up every two weeks and get it hot.
I also carry a heavy duty lithium start pack for that "just in case" moment, but hoping to negate any issues in the first instance.

Re NZMCA, yup I think it is a very good system. A lot of freedom camping sites around the country. Most are courtesy of the local councils, as are the dump stations. All of which are free.
NZMCA also has its own "parks" around the country. Most towns have a site and are only around $8.00/night
Some don't have any ammenities, but some do. None have EHU. All are hard-standing. Some sites can handle over 50 vehicles or more. No issues with awnings out (no extra charge) plus all the required BBQ and wine dinking tools
They are also a very safe place to park up for a few nights or more.
We use both these sites and freedom sites.

 

[Mike001]

PS: I think I am just a serial tinkerer.

 

[autorouter]

I was going to suggest a Sterling 12V-to-24V battery maintainer but if it isn't suitable for lithium as jongood says then that's no good. I have a setup with a big lithium battery and inverter, and my solution is to use a mains battery maintainer powered from the inverter. The starter battery is 12V, so I use a CTEK 5A connected to the starter battery, and it works fine. I leave it connected, so it works whenever the inverter is switched on.

Victron do a 24V 5A battery charger that should be suitable, one of these maybe:

Blue Smart IP65 Charger (120V and 230V) - Victron Energy

The Blue Smart IP65 Charger is the new professional battery charger with built-in bluetooth. Find a Victron Energy dealer near you.

www.victronenergy.com

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[jongood]

PS: I think I am just a serial tinkerer.

You're in good conpany here then

I was going to suggest a Sterling 12V-to-24V battery maintainer but if it isn't suitable for lithium as jongood says then that's no good. I have a setup with a big lithium battery and inverter, and my solution is to use a mains battery maintainer powered from the inverter. The starter battery is 12V, so I use a CTEK 5A connected to the starter battery, and it works fine. I leave it connected, so it works whenever the inverter is switched on.

Victron do a 24V 5A battery charger that should be suitable, one of these maybe:

Blue Smart IP65 Charger (120V and 230V) - Victron Energy

The Blue Smart IP65 Charger is the new professional battery charger with built-in bluetooth. Find a Victron Energy dealer near you.

www.victronenergy.com

Thats not a bad idea, Mike001 Don't know what your set up is but I could hook up my existing 24v charger to do this