24V house batteries?

Wowbagger · 12-31-2015, 03:54 PM

Has anybody else done a 24V house battery? When I was working with SMB Texas they indicated that 24V was pretty rare, but in order to get the power levels out of the inverter I want, 24V was the only way to go.

Also, has anybody else had any luck getting a bracket for a second alternator on a diesel Promaster? I may have to take mine in to Nations Alternator so they can work out what the bracket needs to be, as it seems they don't have any access to a diesel Promaster to work it out.

boywonder · 12-31-2015, 06:11 PM

...just wire two house batteries in series.......voila! ...... 24VDC

The next question is what about everything else that is powered off of the house batteries?

Wowbagger · 12-31-2015, 06:46 PM

Well, actually I am running 6 sets of 12V LiFeMnPO4 100Ah batteries for 24V@300Ah. It's more getting things like the Danhard and Espar set up with the 24V versions of the fans (for tractor/trailer use) rather than the 12V versions. That's also why I need the second alternator - to charge the batteries, as the main alternator won't do.

Since SMB Texas really didn't have the expertise, I actually handled specing that part of the design myself - and I had the guys there taking notes over my shoulder.

carringb · 12-31-2015, 07:21 PM

I don't get it. You can can get plenty of watts out of 12-volts. Just need the appropriately sized cables. I installed a 4,000 watt pure sine wave commercial inverter in a party bus, and it's 12 volts. Just put the inverter close to the battery bank -OR- use bigger cables. Sounds like unnecessary complication.

What's the benefit of using 24-volts HVAC? Plenty of large rigs use 12-volt for that too!

**daveb** · 12-31-2015, 08:18 PM

Size of the unit??? I have seen some 24 volt systems are more compact and a few put out more cooling BTU's with their 24v AC's compared to the 12v models.

Scalf77 · 01-01-2016, 08:24 AM

So you are going 24 volt house system, and LiFeMnPO4 also? There are a couple of boaters on the forum, that might have experience with 24 Volt systems.

What inverter, charger and battery our you using for your system?

Any reason why you are choosing to go with 6 100 AH batteries?

-greg

Wowbagger · 01-01-2016, 08:35 AM

Magnum Energy MSH-4024 as the inverter/charger (that will give me a total of 60A of current when on shore power, and 35A when on battery), with (hopefully!) a Nations Alternator 170A alternator to charge from the engine. I wanted enough battery to be able to have a reasonable chance to run A/C all night (figuring roughly 1kW for the A/C, roughly a 40% duty cycle, ca. 4 hours run time giving a total of 9 hours cooling at 40%), and to be able to fit the batteries under the rig, 3 sets of 2 batteries in series gave the needed run time. It actually worked out well - the battery box fits right under the rig, and actually has more ground clearance than the usual battery set up SMB does.

Unfortunately, Nations Alternator hasn't had access to a diesel Promaster to work out the brackets for a second alternator yet; I am working with SMB Texas to arrange to go to Nations Alternator to let my van be the guinea pig for the work.

Scalf77 · 01-01-2016, 10:36 AM

I guess my question was why not build a 300 AMP 24 Volt battery with a BMS system to directly support 24 volts. Having the the six individual batteries is series and parallel seem to make it more challenging. Not sure what Batteries you are using.

What alternator are you going to use? what kind of regulator and stuff like that. As much as some of these Lithium battery manufacturers like to make you thing they are plug and play compatible, reality does not support that, at least if you want to be able to get their projected life span out of their product.

-greg

Wowbagger · 01-01-2016, 10:48 AM

The batteries are Elite Power Systems batteries, they come a pre-assembled 12V@100Ah units. The BMS is configured to support the series/parallel layout. They don't have 300Ah cells directly, and even if they did, the size would likely not work out for being placed under the chassis as I am doing.

The alternator that SMB Texas was going to get from Nations Alternator is a 24V 170A unit - it's just getting the brackets worked out that is the hang up.

Scalf77 · 01-01-2016, 02:04 PM

Got it. I am in sync with you now. Do you know what the voltage output of the alternator is?
Sounds, like a fun install.

-greg