24v Inverter?

[wamcneil]

Hi all,

I've got what might be a crazy idea.

The problem: My batteries are waaaaaay at the back of the coach right-rear. But my inverter is up forward on the left. 4/0 cables between, but still a lot of voltage drop at high current. No easy way to fix this, unfortunately...

Moving the inverter closer to the batteries has entered my mind, but then I'd need to re-route a lot of wiring.😞 

What if I replaced the inverter with a 24v inverter? Dropping the current in half should get my voltage drop down to the 3% range. 

• Other than the obvious voltage change, a 24v Magnum inverter/charger would be plug-n-play swap for the existing MS2012.
• Solar controller can run 12v or 24v, so that would only be a dip switch setting.
• It would be pretty simple to separate the 4/0 cable run from the high-current run-bay and repurpose it for 24v, then wire the existing house batteries in series for 24v
• Magnum AGS is good with 12v or 24v 
• I've got enough room on top of the batteries to install another 12v battery for the house loads and run cables back to the high-current run bay to feed everything except the inverter.
• Add small 12v charger or 24v/12v converter for new house battery

Anything I'm missing that might make this plan end in sadness?

I remember needing to connect the neg inverter cable to the chassis and the neg battery cable. I suppose I'll need to connect the new 12v battery neg to the chassis when I disconnect the inverter from the chassis.

Thanks,

Walter

[Ivan K]

I would think that your plan is doable but way more than I would be willing to do. Are you planning to run your air-conditioning on inverter or why do you worry about the loss so much? Perfection? Faster charging or some huge AC loads in your future? Just curious...

[waterskier_1]

I have the same question as Ivan.  Why such a high load?  Using the microwave?  I just start my generator, even though my batteries/inverter will run the microwave for a while, you still have to put the electrons back in the batteries.  You would basically have two separate and isolated systems.  One 12 Volt, but with only one battery to support all the house, and a second to support the inverter.  The inverter's built in charger will have to be capable of charging your 24 Volt battery bank.  That will be the only method (besides potentially solar, depending on how they are wired and the controllers).  My bigger concern is that it's quite doubtful that one 12 Volt battery (unless it's something unique, like a 12 Volt, 300 AH Lithium battery) won't be able to run everything in your coach.  Besides the TV and associated electronics, and the microwave, what power hungry devices are you running?  Have you computed how much power you single 12 Volt house battery would need as far as amp-hours?  

 

[wamcneil]

No huge loads like AC. It’s mostly to run the microwave or induction cooktop and warm up leftovers without feeling like I need to fire up the generator every day. Recharge mostly with solar (1100w).

It’s looking like I may have an extra 270ah lithium battery to use for the house loads. I haven’t tried to calculate the house loads separate from the inverter, but that’s the big power consumer  (fridge mostly, coffee maker, computer, tv). Other house loads are just led lights, water pump and in winter the aqua hot would probably be the biggest consumer.

Cheers

Walter

[monacoanarchist]

Hi there,  I will try to insert photos of my 12v/24v/48v system with descriptive captions:

The photos below depict and describe my current system and should be self explanatory: I installed all this during the winter of 2015.  It has been performing flawlessly since then.  A few weeks ago I replaced the existing 4 six volt house batteries with one 12v-100Ah LiFePO4 battery from Battle Born.  They were on their last legs and needed to be replaced anyway.  I then purchased 6 more 12v-100Ah Battle Borns to replace my 8 golf cart batteries.  They will be hooked up series/parallel for 24v-300Ah.  We have been full time RVers for almost 20 years now,  dry camping 99% of the time. If there are any questions about the system, I will be happy to reply. Michael Connor 2003 Diplomat 38PBDD, electric fridge, electric oven, no generator.                 Full system: Ten 24v solar panels, 6 on motorhome + 4 more on trailer, approx. 2,500 watts nominal, and one 12v 145watt panel which is now charging the 12v-100Ah battery I recently bought from you guys. Best Regards, Michael Connor

 

[wamcneil]

Nice setup! Thanks for sharing that Michael 

[Scotty Hutto]

@monacoanarchist That’s a sweet setup!  Very cool and inspiring.