Forum Discussion

HomeSlice's avatar
HomeSlice
Explorer
Apr 22, 2021

What is a “converter”?

I see it referenced a lot on RV sites and groups, in the context of an electrical system component. I have no idea what it refers to, however.

Is this a battery charger, inverter, charge controller, or something else?
  • Kayteg1 wrote:
    valhalla360 wrote:

    As far as the name, you could as easily say an inverter CONVERTS from 12vDC to 120vAC and it's true ....


    You can't convert AC from DC.
    You have to invent AC current using electronic devices and then you can convert to desired voltage.
    Over the years converters went via several designs.
    Back in 1980's they would supply 12VAC for RV lights and water pump, when small DC circuit would charge the battery and operate radio.
    Then some designs put 12VDC converter parallel to the battery, some disconnects the battery from RV when on converter.
    That surprised me lately as 20 yo converter was showing 18V on new digital gauge.
    Took few forum experts (not on this forum) to figure out that converting AC with electronic circuit, the voltage spikes high for microsecond, before it levels at ca 12V.
    Analog meters will not register it, some digital multimeter will not register it, but cheap meter that come with lighter socket does.


    Sure it can. 12vDC goes in one side, is converted to 1120vAC out the other side. Convert and Invert aren't well defined terms and outside of the RV world, you will never hear of a battery charger referred to as a converter.

    Went ahead and looked it up. The definitions for converter are all over the place. Some describe what you do that it only converts the voltage but not AC to DC. Others say it also converts AC to DC. Even found one that.

    A battery charger doesn't leave the ambiguity.
  • valhalla360 wrote:

    As far as the name, you could as easily say an inverter CONVERTS from 12vDC to 120vAC and it's true ....


    You can't convert AC from DC.
    You have to invent AC current using electronic devices and then you can convert to desired voltage.
    Over the years converters went via several designs.
    Back in 1980's they would supply 12VAC for RV lights and water pump, when small DC circuit would charge the battery and operate radio.
    Then some designs put 12VDC converter parallel to the battery, some disconnects the battery from RV when on converter.
    That surprised me lately as 20 yo converter was showing 18V on new digital gauge.
    Took few forum experts (not on this forum) to figure out that converting AC with electronic circuit, the voltage spikes high for microsecond, before it levels at ca 12V.
    Analog meters will not register it, some digital multimeter will not register it, but cheap meter that come with lighter socket does.
  • Yes as others have described converts AC to DC, regulates charge to batteries.
    Generally also serves as distribution point for AC and DC lines.
    Where AC breakers and DC fuses located.
  • mkirsch wrote:
    valhalla360 wrote:
    It's a battery charger. Never made sense why RVs use a different name.

    Yes, you can draw off it directly but you can do that with a battery charger too.


    That is not entirely correct. You cannot (safely) draw directly off of a battery charger because it is not regulated. A battery charger's output varies depending on load. It can start out at 19V or higher with a very light load (or on the high-Amp charge setting) and drop to below 11V with a heavy load.

    IF what you are trying to run isn't terribly voltage-sensitive, then sure. However sensitive electronic devices looking for a 12V input are going to have problems on raw 19V+ from a battery charger.

    A converter has a regulated voltage output. It is called a converter because it CONVERTS 120VAC to 12VDC, the opposite of an inverter which INVERTS 12VDC into 120VAC. Not all converters are battery chargers, as pointed out above.


    If you are talking about the really old RV systems which might not have incorporated a battery...they didn't have voltage sensitive devices, so it was largely irrelevant. Any new RV has a battery in the system, so it's irrelevant. It's a battery charger for all intents and purposes.

    As far as the name, you could as easily say an inverter CONVERTS from 12vDC to 120vAC and it's true ...inverter is at least consistent with usage outside the RV industry. If you ask someone with a cruising boat about their "converter" they will look at you funny until you explain you are asking about their battery charger.
  • valhalla360 wrote:
    It's a battery charger. Never made sense why RVs use a different name.

    Yes, you can draw off it directly but you can do that with a battery charger too.


    That is not entirely correct. You cannot (safely) draw directly off of a battery charger because it is not regulated. A battery charger's output varies depending on load. It can start out at 19V or higher with a very light load (or on the high-Amp charge setting) and drop to below 11V with a heavy load.

    IF what you are trying to run isn't terribly voltage-sensitive, then sure. However sensitive electronic devices looking for a 12V input are going to have problems on raw 19V+ from a battery charger.

    A converter has a regulated voltage output. It is called a converter because it CONVERTS 120VAC to 12VDC, the opposite of an inverter which INVERTS 12VDC into 120VAC. Not all converters are battery chargers, as pointed out above.
  • It's a battery charger. Never made sense why RVs use a different name.

    Yes, you can draw off it directly but you can do that with a battery charger too.

    Newer/bigger RVs often upgrade to a combined inverter/charger, which can also take the 12vDC battery power and output 120vAC if not on shore power.
  • wnjj's avatar
    wnjj
    Explorer II
    CA Traveler wrote:
    In RV speak converter and battery charger are the same.

    Not always. Two different tent trailers I've been around in the past have had a converter that only provided 12V for accessories and did not charge the battery. They had a switch to pick battery or converter for the 12V supply source.

    It wouldn't surprise me if older model truck campers were the same way.
  • A converter converts 110/120v to 12v. It allows you to operate the 12v systems in the RV, such as lights, water pump, etc, while connected to shore power. Most all RVs come with a converter. It is usually a combination converter/charger so it can charge your batteries while hooked up to shore power.

    An inverter inverts power from 12v to 110/120v. Allowing you to operate household electronics while NOT plugged into shore power. Very few RVs come standard with an inverter.