RV Energy Storage - Efficiency

[MemoriesByTheMile]

As we have researched solar systems and specifically energy storage for solar, when looking at higher amperage use cases (such as homes or prevosts) they all will use higher voltage systems, such as 48v or higher.

Since we got into RVs and have a lithium battery system, the sizing of wiring has amazed me.

If higher voltages were used in an RV energy storage system, much smaller wiring gauges could be used, which would reduce the cost of copper in an installation and make installation and maintenance much easier in small spaces.

Has anyone here considered, attempted or completed a conversion to 48v batteries instead of using 12v?

Victron offers both 12v and 48v systems.

Of course, would need transform from 48v to 12v to drive the house 12v systems (as there are too many house components that are only available in 12v).

 

[Kevin D Pem]

As we have researched solar systems and specifically energy storage for solar, when looking at higher amperage use cases (such as homes or prevosts) they all will use higher voltage systems, such as 48v or higher.

Since we got into RVs and have a lithium battery system, the sizing of wiring has amazed me.

If higher voltages were used in an RV energy storage system, much smaller wiring gauges could be used, which would reduce the cost of copper in an installation and make installation and maintenance much easier in small spaces.

Has anyone here considered, attempted or completed a conversion to 48v batteries instead of using 12v?

Victron offers both 12v and 48v systems.

Of course, would need transform from 48v to 12v to drive the house 12v systems (as there are too many house components that are only available in 12v).

Think it comes down to component cost, and count.

My house consists of a small (500 watt) 12 volt system. My inverter system is 48 volt system. That gives me a 6000 watt inverter, and without increasing batteries, is limited to 1000 w of solar configured to charge the 48 v system.

Note that over 48 volts is no longer a low voltage system. The solar side of the controller is 70 volts open.

For many years I avoided 48 v due to limited space for batteries.

If I doubled battery capacity, I could double solar, but in reality, I have a 50 amp inverter, and a 30 amp trailer service connection.

I will add in the other panels I have, using micro-inverters to use directly on the AC unit.

That should give you some to think about.

 

[GTS225]

And you shouldn't forget to factor in the intrinsic losses converting back down to 12vdc or 24vdc, (depending on what the mfgr rigged your house in). I suggest that the rule of diminishing returns kicks in rather soon, making the investment in wiring size savings no longer worth the trouble.

BTW......and first-year electrician knows all about higher voltages and smaller wiring needs. (I.E.; double the voltage and you cut the current needs in half, leading to smaller wiring requirements. There's only a handful of countries that use 120 VAC to any great extent. Most of Europe typically has 220/230 single phase for their household wiring.

Roger

 

[Kevin D Pem]

And you shouldn't forget to factor in the intrinsic losses converting back down to 12vdc or 24vdc, (depending on what the mfgr rigged your house in). I suggest that the rule of diminishing returns kicks in rather soon, making the investment in wiring size savings no longer worth the trouble.

BTW......and first-year electrician knows all about higher voltages and smaller wiring needs. (I.E.; double the voltage and you cut the current needs in half, leading to smaller wiring requirements. There's only a handful of countries that use 120 VAC to any great extent. Most of Europe typically has 220/230 single phase for their household wiring.

Roger

Think the wire size issue is ability to fish in tighter locations. I paralleled 10 AWG for a circuit that has the capability to only produce 20 amps DC. Why because fishing is easy!

 

[GTS225]

Done that myself for a high amp branch circuit. T'was a whole bunch easier pulling smaller wires through a conduit instead of four rather large, stiff wires for the same capability.

But for the record, I hardly think that would be an issue in an RV. Even 50 amps is what.....6 gauge? If one can't maneuver that around a corner, then one needs more muscle tone.

Roger

Think the wire size issue is ability to fish in tighter locations. I paralleled 10 AWG for a circuit that has the capability to only produce 20 amps DC. Why because fishing is easy!

 

[Kevin D Pem]

Done that myself for a high amp branch circuit. T'was a whole bunch easier pulling smaller wires through a conduit instead of four rather large, stiff wires for the same capability.

But for the record, I hardly think that would be an issue in an RV. Even 50 amps is what.....6 gauge? If one can't maneuver that around a corner, then one needs more muscle tone.

Roger

My IKEA build trailer requires finesse, not muscle tone! No! Definitely,there is a time for small fine stranded silicone insulated wire. Well suited for RV work!!!

Does require deep pockets, but Is well worth the money!