Wiring Woes

[erfnie]

Generator, gennie jenny genset

converts fossil fuel to AC power, output.

Substitute for shore power when off grid.

Noisy and expensive supplement to solar, or alternator use while driving.

Ahhh, I get it now. Thanks for the explanation. Seems I'm learning lots of new terms lately on this forum

[erfnie]

Tony[/quote]

And for stationary charging, you could add one of these ports along with a 120v smart charger.

Ok, our plans are shifting. I did some more reading and would like to do something like the Super Simple Electrical plan for AC since we have wires in for that already.
But then for the DC, (using only battery for now), we'll get the fuse block with negative bus as recommended.

With our setup, the battery will be located in the tool box on the tongue, but the power inlet will be towards the back of the cabin.
New questions:
Is there a way we can charge the battery from the back of the cabin where the plug will be? (as in hooking it up to the leads on the fuse/neg block?)
Or do we have to put the charger close to the battery to connect it directly to the posts on the battery? (And have to plug it in there?)

Tony, looks like this inlet is towards the back of the TD. Is the battery and charger close to that in the back too?

I put one in my sister's little 'drop.

[tony.latham]

Tony, looks like this inlet is towards the back of the TD. Is the battery and charger close to that in the back too?

I chose that location to power her CPAP when parked near a 120V source.

But yes, I can't see any issue with hard-wiring the charger to a fuse block in the galley. Just make sure to read up on wire size for the run between the battery and fuse block. I would guess that 12 AWG would be fine.

Tony

[erfnie]

But yes, I can't see any issue with hard-wiring the charger to a fuse block in the galley. Just make sure to read up on wire size for the run between the battery and fuse block. I would guess that 12 AWG would be fine.

Well, we're going with 8AWG since it's about 15 ft, so I'm thinking we'll be ok. I'll read up some more to be sure. My only other concern is if it would negatively affect the DC circuit in any way, especially if we used a light or two while it was plugged in and charging at the same time.

[bdosborn]

Blue Seas has a nice Circuit Wizard to help you size the wire. 15 ft is where I start looking for voltage drop being an issue. One volt per foot is the rule of thumb i.e. anything longer than 12 feet at 12v needs to be upsized for voltage drop. Just put in the charger size for load amps and use 75C for the wire insulation temperature, unless you're using marine wire.
http://circuitwizard.bluesea.com/#

Your #8 should be good for 30A at 15'. I'd use a 30A fuse for the circuit.

Bruce

[erfnie]

Blue Seas has a nice Circuit Wizard to help you size the wire. 15 ft is where I start looking for voltage drop being an issue. One volt per foot is the rule of thumb i.e. anything longer than 12 feet at 12v needs to be upsized for voltage drop. Just put in the charger size for load amps and use 75C for the wire insulation temperature, unless you're using marine wire.http://circuitwizard.bluesea.com/#
Your #8 should be good for 30A at 15'. I'd use a 30A fuse for the circuit.
Bruce

Thanks for the info and suggestions. About the "charger size", I was looking at some NOCO chargers and see that they have different amps (1, 5, 10amp). How do you choose the correct charger?
I'm guessing it has to do with the size battery we choose?

[John61CT]

Those are tiny garage style for Starter motors.

A proper charger for most deep cycling banks starts at 20/40/60A, looking at $3-400+ usually for good quality.

FLA will only accept a 0.2C rate, AGM should really start there at a bare minimum, 0.4C would be better for longevity.

I also would reco full user-custom adjustability on the voltage profile, so you are free to switch chemistries later without replacing your charger.

[tony.latham]

I was looking at some NOCO chargers and see that they have different amps (1, 5, 10amp). How do you choose the correct charger?

I've got one of these and it works great:

https://www.amazon.com/gp/product/B004LWVEKS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Tony

[bdosborn]

The rule of thumb for lead acid batteries is 10% of C. If it's a 100 amp-hr battery, you'll get the longest battery life if you have a 10 amp charger. We're not using our batteries everyday so a smaller charger is an option that won't effect battery life by much, It's more important to keep the battery on the charger when not in use and charge it back up as soon as possible after using it.

Bruce

[John61CT]

Deep cycle AGM, 0.2C is minimum, Enersys / Odyssey reco is 0.4C

for best longevity

[bdosborn]

Not according to Trojan, do you have a link to where you found that info?

[erfnie]

Update...
We've decided on a super simple system (I think ). Each side is independent of each other.
For the AC side, there are 120V outlets connected to a power block in our power center that gets plugged in only when or if shore power is available.
For the DC side, power will come from the battery and fuse block and we will probably hook up a solar panel right away as well.

Which leads me some new questions... Is a battery charger even necessary if solar is present to keep the battery charged? What do you do in winter? Does the solar ever get "turned off" if that's even possible?

[John61CT]

Not according to Trojan, do you have a link to where you found that info?

Trojan what?

They don't even make AGM suited for true deep cycling use cases.

The three main ones in NA that do all say the same

Odyssey, Northstar and Lifeline

Each have tech support readily available to ask if you don't see it in their published docs.

Of course with a big bank maybe a given rig just can't get that high

we can only do our best, the ideal is sometimes too impractical, so be it.

[John61CT]

Is a battery charger even necessary if solar is present to keep the battery charged?

Depends on your usage and situation, the bank does need to get to 100% Full as often as possible, and often solar is not enough to get there, takes over 6 hours after all with lead, no matter how many amps are available.

Best to be able to grab energy input from every opportunity, and often overnight on mains is the only source certain to get there

> What do you do in winter?

You mean living off grid? A genny helps, but best in the morning when CAR is high.

> Does the solar ever get "turned off" if that's even possible?

Just toss a blanket over the panels, or disconnect them from the SC (before the bank).

Some have a switch.

[tony.latham]

Which leads me some new questions... Is a battery charger even necessary if solar is present to keep the battery charged? What do you do in winter? Does the solar ever get "turned off" if that's even possible?

My teardrop (and thus the panels) is covered during the winter. When I put it into hibernation, it gets hooked up to a charger to maintain the battery.



The only time my solar panels are "turned off" is when I hit the breaker to disconnect them. I have that option because my Renogy controller manual tells me not to disconnect the battery if the panels are connected. But it's an odd event.



Otherwise, the system is always cooking.

Tony