Diff between Inverter & Converter Charger & battery drain

Without reading all the replies above......

We have a 2000 watt Tripp-Lite whole house inverter in our Phoenix Crusier. When the motor home is at home not being used, I kill the power to the entire house through the main kill switch by the entry door. Otherwise the batteries will drain fairly quickly. With the power killed, nothing will function yet there is still a very minor drain on the batteries, so I put a 4 amp charger for a day or so on the batteries once every-other month to compensate for the minor drain.

If I was storing our rig off site, I would store the rig with a full charge and disconnect the batteries.

The inverter charges the batteries when the rig is plugged into shore power or when the generator is running, but the charge is a lower "maintenance" charge. With heavily drained batteries, it takes a day or two to bring them back to full.

We dry camp a lot so when I need to charge the batteries quickly, I use a secondary 40 amp charger running off the generator as seen below. This so the genny run time is greatly reduced. Driving the motor home will also charge the batteries quickly, but if parked a lot through the use of a tow vehicle, I can't rely on that one.



There are a lot of other points to consider with an inverter. If you go from RV park to RV park, it's a no brainer....just enjoy the conveniences of the inverter along the way. But if you dry camp a lot without shore power, you have to watch things closely. Our inverter turned on sitting idle will draw a whopping 12 amp hours. Because we rarely have the benefit of shore power, we developed the habit of turning on the inverter only when we need 110V like making a pot of coffee or watching a late night movie. This to conserve our battery reserves.

nadsab wrote:
You mean it connects to the chassis (engine) battery as well?

Probably not. However it is easy to add "Trik-L-Start" combiner to keep the chassis battery charged when stored plugged in.

As stated above, many RV's have no device that charges the chassis/starting battery while rig is parked and plugged into "shore power" . Some recent Winnebagos had Trik-L-Starts installed by their factory. I installed a Trik-L-Start device which diverts some of the converter's charging current for the house battery, to charge the chassis/starting battery (also) when rig is plugged into shore power. I had to run a heavy guage insulated wire from the device in the house battery compartment to the starting battery positive terminal with a circuit breaker because I couldn't find a solenoid device, as mentioned in the installation instructions, on our 2004 Tioga 26Q.

PS: A few RV's come with a "BIRD" device from the factory, to do the same thing as the Trik-L-Start device

nadsab wrote:
You mean it connects to the chassis (engine) battery as well?

Not usually on a C, original equipment. There are add-on devices to charge the chassis battery from the converter, when there is a current from the convertor, but more often on a C you will have only a boost switch, a momentary contact device to connect house and chassis batteries for an engine starting emergency.

More common on a C will be an isolator (switch or solid state device) that connects the house battery and 12V circuits to the chassis 12V when the alternator has sufficient output.

Otherwise, engine battery and house battery and circuits are not connected, so that the battery on one side does not drain the battery on the other.

The inverter, if you have one, converts 12V DC to 120V AC. It will drain the battery if left on, because it draws some power at no load. Some types draw significant power at no load.

A C most often has a small inverter to power some entertainment systems while driving or when stopped without a power hookup.

Some larger RVs have a whole-house inverter (and huge battery banks, more powerful alternators) to power most of the 120V systems from storage battery or alternator. These units are typically combined with the battery charger. These would also be switched off for storage.

here is a typical RV 30AMP wiring configuration



Roy Ken

You mean it connects to the chassis (engine) battery as well?

nadsab wrote:
Thanks for the info.

So I am assuming that a Converter-Charger also works to charge the 12 volt house battery when either the Generator is running or when the house is plugged in to 120 volts correct?

That's correct. Typical converter connects to both batteries and DC distribution panel. Depending on rig the converter can also charge chassis battery but that's not common on typical rig.

If you can leave the RV plugged in all Winter, the battery can stay connected. When fully charged the battery will not freeze.

The 7345 just provides a steady 13.6 volts. This runs all accessories and will keep the battery charged.

Other things will discharge the battery if it is not charging such as propane detector, radio memory and appliance control boards.

An inverter uses battery power to make 120vac. This only drains the battery. You apparently do not have an inverter. Some larger inverters also will charge the battery when you are plugged in. This you do not have either. 7345 is just a converter that uses 120vac to make 13.6vdc.

Thanks for the info.

So I am assuming that a Converter-Charger also works to charge the 12 volt house battery when either the Generator is running or when the house is plugged in to 120 volts correct?

Inverter changes 12 volt DC to 120 volt AC power. A CONVERTER changes 120 volt AC to 12 volt DC.

Turning your converter off for winter storage will not NECESSARILY protect your battery from drain. If you have an isolator switch installed and it's correctly wired, THAT will protect against discharge but one SURE FIRE method is to simply disconnect the negative lead from your battery(s) while in storage. Usually your detectors (Lp and or CO) are wired directly into your electrical system and those alone can cause a fair amount of discharge. Turning off the converter will probably NOT turn off these items.