inverter/charger question

[mixedpuppy]

I'm considering replacing a converter with and inverter/charger I simply assumed that the inverter/charger would operate similar to the converter...if on shore power and the battery is disconnected, it would supply power for the 12 volt systems. I'm beginning to think that is a very wrong assumption, can anyone clarify for me?

[kscherzi]

The converter down volts from 120 volts to 12 volts.

[mixedpuppy]

I know what a converter does, and I know what an inverter and inverter/charger does. The question is: do [any] inverter/chargers provide power to the 12 volt circuit when on shore power and the battery is disconnected?

[J. Morgan]

How many 12 volt amps will the charger inverter you are looking at produce?


If it makes enough amps to run your trailer it should work without a battery,,,, I would think anyway.

Superat stultitia.

[mixedpuppy]

I'm looking specifically at the Xantrex Prosine 2.0 or the Magnum MS2012 since they both have customizable charge settings that can work with lithium batteries. Both are 100amp chargers.

I was emailing with someone at Xantrex to make sure I'd look at the correct unit for my needs, I don't know what made me ask the question, but they said that it would NOT power the 12v circuit if the battery were disconnected. Then I saw Lewster make a similar statement in another thread.

[BAB]

Yes, the Magnum will do what you want. I have the Magnum MSH3012 (the 3000W model). When I installed it in my trailer I simply disconnected the cheap Chinese job that is integrated into trailer's electrical panel. It's still there, and if my Magnum ever failed (unlikely, it's made in the USA), I could wire it back in (would take about a minute). My setup is pretty elaborate. I installed the Magnum 2 weeks after my Classic was delivered and it has been fantastic. I was in a park last summer during a major heat wave. Their electrical system was providing about 108V. The Magnum's sophisticated circuitry detected that and converted some of my 12V power to provide another 12V so I wouldn't "underplot" my system -- which I don't think the A/C likes.

[lewster]

Originally Posted by mixedpuppy

I'm considering replacing a converter with and inverter/charger I simply assumed that the inverter/charger would operate similar to the converter...if on shore power and the battery is disconnected, it would supply power for the 12 volt systems. I'm beginning to think that is a very wrong assumption, can anyone clarify for me?

pup,

Here's how the various systems operate:

CONVERTER:
Takes 120VAC shore power and produces 12VDC. This 12VDC is then used to power all of your DC needs in the trailer (lights, control boards, furnace, etc.) and also produces a charge for the batteries with the remaining available amperage. The best converters, even the 3-stage models, only approximate your batteries' needs but they all miss the mark to some extent. The converter powers your 12VDC loads directly while on shore power and your batteries do the same when no shore power is available.

INVERTER/CHARGER
Takes 120VAC shore power and 'passes it thru' to the 120VAC circuits that you have wired to the inverter's output. The shore power also energizes the charge circuit in the device to provide charge voltage your batteries. Regardless of the power source (shore power present or not), your batteries power all of your 12VDC loads

The 'inverter' side of this device uses 12VDC power directly from the batteries when off-grid to produce 120VAC power that is used to energize any outlets or devices that you have wired to the output side of the inverter/charger.

As for choice of devices, Magnum is made in the USA (NOT CHINA) and is fully field repairable with a 3 year warranty. Xantrex is MADE IN CHINA and is basically a throw-away device if (actually when) it goes T/U.

Plus, the Magnum is FULLY programmable and can be used for custom settings that will perfectly match the requirements for differing battery types (including lithium). Xantrex uses set charge profiles that might not perfectly suit your batteries' requirements.

[ArtisanAir]

I don't think it does. it just charges the batteries but does not have the ability to have a constant draw of DC power off of the inverter....

[lewster]

All modern converters produce 12VDC directly to your fuse panel and power all of those loads regardless of whether a battery is present or not.

An inverter/charger charges the battery when on shore power but will not operate without a battery in place.

[mixedpuppy]

Originally Posted by lewster

INVERTER/CHARGER
Regardless of the power source (shore power present or not), your batteries power all of your 12VDC loads

This is exactly what I was trying to get to, whether or not you could disconnect the batteries when on shore power if you use an inverter/charger.

Given that at this stage [for various reasons] we're stuck to vancouver where we'll only be on shore power, seems like a waste to cycle the batteries this way, but the other benefits probably outweigh that.

[lewster]

Originally Posted by mixedpuppy

This is exactly what I was trying to get to, whether or not you could disconnect the batteries when on shore power if you use an inverter/charger.

Given that at this stage [for various reasons] we're stuck to vancouver where we'll only be on shore power, seems like a waste to cycle the batteries this way, but the other benefits probably outweigh that.

You won't be wasting batteries with an inverter/charger if it is properly programmed for the batteries that you choose. If you find yourself on shore power all or most of the time, you will be placing a minimal draw on your batteries, as the inverter's charging section will keep those batteries topped up most or all of the time, only allowing for a slight battery discharge before starting the re-charge cycle.

An example of minimal 'battery use vs. # of charge cycles' can be found in the Lifeline battery tech manual. The 'typical' number of charge cycles at 50% depth of discharge is 1000 cycles. If you only draw your batteries to 10% depth of discharge, the number of cycles you can expect balloons to 5000! Assuming that you keep your batteries in otherwise good health (proper water levels for liquid cells, etc.), you can expect extremely long life from any battery than you choose to put into a system with an inverter/charger IF you will be connected to shore power 24/7/365.

But as a counterpoint, IF you plan on being plugged in all of the time, why bother with the expense of an inverter/charger and battery. The CONVERTER will provide all of your required 12VDC power and the shore power will provide all of the 120VAC power......even the single stage POS that Airstream provides as stock equipment! The only time you would NEED a battery is IF you take the trailer on the road. Then it is required to have a battery that is capable of powering your trailer brakes in the event of a detachment from the tow vehicle.

[mixedpuppy]

Originally Posted by lewster

But as a counterpoint, IF you plan on being plugged in all of the time, why bother with the expense of an inverter/charger and battery. The CONVERTER will provide all of your required 12VDC power and the shore power will provide all of the 120VAC power......even the single stage POS that Airstream provides as stock equipment! The only time you would NEED a battery is IF you take the trailer on the road. Then it is required to have a battery that is capable of powering your trailer brakes in the event of a detachment from the tow vehicle.

I was in process of doing a series of upgrades when life took a detour. Now I'm working towards finishing a number of upgrades by year end when we'll be able to get back to our nomadic plans.

The converter [not stock] has been fine, but is rather pathetic at charging the lithiums even though I can set the voltage to 14.2. It seems to time out on bulk well before hitting the set voltage.

[lewster]

Originally Posted by mixedpuppy

I was in process of doing a series of upgrades when life took a detour. Now I'm working towards finishing a number of upgrades by year end when we'll be able to get back to our nomadic plans.

The converter [not stock] has been fine, but is rather pathetic at charging the lithiums even though I can set the voltage to 14.2. It seems to time out on bulk well before hitting the set voltage.

Hmmmmmmm............

With lithiums you definitely need a Magnum!!!

[mixedpuppy]

Originally Posted by lewster

Hmmmmmmm............

With lithiums you definitely need a Magnum!!!

That was always the plan