Step by step electronics update/upgrade

[paul65k]

Originally Posted by wolfe10

We both agree, large gauge from battery bank to inverter (short run, hopefully).


But, no need for 4/0 to either the OE battery location or directly to the 12 VDC fuse boxes.

But between the batteries, I would also use 4/0....with that draw what could it hurt, especially if making your own cables?

[wolfe10]

Originally Posted by paul65k

But between the batteries, I would also use 4/0....with that draw what could it hurt, especially if making your own cables?

As you suggest, inner-bank connections should be the same gauge as wiring to inverter (4/0) as electrons have to make the "round trip".



Only design that would not require using 4/0 would be for each battery to be connected to a common point such as this https://www.bluesea.com/products/cat...tors/PowerPost so that electrons from an individual battery do no "flow through" all the other batteries. BTW, this is the preferred way to wire them, guaranteeing that each battery carry an equal load-- equal length runs to common point for both positive and negative/ground.




And, proper gauge from new battery location to either OE location or directly to the fuse blocks should be determined by: Maximum draw of all house 12 VDC loads that reasonably could be run at the same time, length of run and 3% voltage loss table).



The good news is that each of these variables is verifiable, so no guess work needed.

[paul65k]

Originally Posted by wolfe10

As you suggest, inner-bank connections should be the same gauge as wiring to inverter (4/0) as electrons have to make the "round trip".



Only design that would not require using 4/0 would be for each battery to be connected to a common point such as this https://www.bluesea.com/products/cat...tors/PowerPost so that electrons from an individual battery do no "flow through" all the other batteries. BTW, this is the preferred way to wire them, guaranteeing that each battery carry an equal load-- equal length runs to common point for both positive and negative/ground.




And, proper gauge from new battery location to either OE location or directly to the fuse blocks should be determined by: Maximum draw of all house 12 VDC loads that reasonably could be run at the same time, length of run and 3% voltage loss table).



The good news is that each of these variables is verifiable, so no guess work needed.

Exactly....I wish we had the room in our battery location to use that buss bar set-up but we just didn't have it in our location.

I did rewire a friends Country Coach recently and we did it with the Buss Bar set-up......even though he had Sealed LA, he will be upgrading to LiPo here pretty soon

[Hayduke]

The cost I quoted was to have ~20ft red and black 4/0 cables with lugs and heat shrink made at Solar Bill's in Quartzsite, AZ. I'm certain I could do better.

I don't want to hijack Brianna's thread more than I have already.

I might still move the batteries, or I might not.

[studesrus]

we installed a 200 W Mono Crystal solar panel, and installed a 1500 W pure sine wave system, now we can use the Microwave for Popcorn or the toaster for a piece of toast late at night when cannot sleep. (no wonder I cannot lose weight). It did not cost me 8k it cost us just over a $1.3k so do not know where your coming from.
Peter

[evofxdwg]

If you haven't pulled the trigger on battery replacement yet, consider LiFePO4, especially since you are planning on changing the converter anyway.

I changed mine over to a 100AH Battleborn LiFePO4, a BMV712 monitor, a LI-BIM 224 auto-control switch (for charge control from engine), and a Progressive Dynamics PD9160ALV converter.

We dont boondock much but before the next multi-week trip I will probably add some more AH to it.

10 year warranty on Battleborn vs maybe 4 expected years and maintenance headache of FLAs kind of balances out the cost.

I did have to do some wire tracing on my motorhome and electrical research since Coachmen does NOT provide good system data. And the LI-BIM-224 switch operated differently than I interpreted from their spec. The BMV 712 does provide data to determine what the battery is doing at any given time and plots up to two hours so I figured out how to control and prepare for storage (LiFePO4 best stored with partial charge from everything I have read).

[Elevensdad]

Originally Posted by Brianna

I am new to RVING so I am hoping you guys can give me some advice.

Ultimately, in a few years, I want to invest in a large solar system, but for budget reasons I need to do it step by step but also address immediate needs.

1. In the meantime i am replacing the sketchy 12v house batteries with four new 6v flooded. (And also replacing the sketchy grp 31 chassis batteries). Essentially returning it to the way it came from the factory. Ultimately I will go lithium and stick them in the storage pocket under the bed but for now this is the best short term solution.

2. I am replacing the 20 year old Big Boy isolator relay because of chassis charging issues.

3. I want to replace the factory inverter, even though it works, because it makes a noticeable hum ( which can't be good) and again, it's 20 years old.

So here's where I need your help.
Should I just get another plug and play inverter, like upgrade to 3000W pure sine, or should I get something like the big victron inverter/charger/transfer switch combo unit? Or something in between?

My new Victron 3000 PSW Multi Inverter/Charger/ATS mounts on the back wall of rear-most cabinet, next to (Lithium) battery compartment. Original Magnum 2000 MSW inverter/Charger was mounted to floor on a raised aluminum platform.

[paul65k]

Originally Posted by Elevensdad

My new Victron 3000 PSW Multi Inverter/Charger/ATS mounts on the back wall of rear-most cabinet, next to (Lithium) battery compartment. Original Magnum 2000 MSW inverter/Charger was mounted to floor on a raised aluminum platform.

Briana,

Pretty sure your inverter is mounted much like ours in the cabinet in the bedroom on the floor. I am getting ready to replace the Xantrex with a Victron Multiplus which prefers to be hung on a wall and only secondarily can be mounted on the floor.

There is room to mount it to the sidewall but in our case, we have already mounted the Solar Controller and solar combiner/breaker there. I have added a 3/4" plywood wall on the opposite side next to the smaller drawers and will mount it there.....this will hopefully provide more room to work in the space and additional airspace for cooling.

Wasn't a big deal and easy to do

[theoldwizard]

Originally Posted by Brianna

1. In the meantime i am replacing the sketchy 12v house batteries with four new 6v flooded.

Smart, cost effective (at least short term) move !

Originally Posted by Brianna

2. I am replacing the 20 year old Big Boy isolator relay because of chassis charging issues.

If you really want to PROPERLY charge those new house batteries while driving, spend the money (that you saved from not going LiFePO4) on a DC-DC charger. There are several on the market.

Originally Posted by Brianna

3. I want to replace the factory inverter, even though it works, because it makes a noticeable hum ( which can't be good) and again, it's 20 years old.

Again, spend the money and get a combination inverter/charger/transfer switch. It will replace your old inverter and you will no longer need a converter ! Easier to install, easier to use.

As for battery cables, you can buy custom made-to-order cables on eBay for very reasonable prices. 4/0 is over kill. 2 AWG is adequate, maybe even 4 AWG depending on the size of your inverter and the length of the cable.

[paul65k]

Originally Posted by theoldwizard

As for battery cables, you can buy custom made-to-order cables on eBay for very reasonable prices. 4/0 is over kill. 2 AWG is adequate, maybe even 4 AWG depending on the size of your inverter and the length of the cable.

If you are going to go to a 3000 W inverter then 4/0 cables will be the right choice......if you stay with 2000W (which doesn't really make sense) then your existing 2/0 cables will be fine, but in your Alpine 2 AWG or 4 AWG is completely undersized