Base / Mobile / Portable Operation Off RV Battery by WD8ARZ

WD8ARZ <wd8arz@...>

Here is my thinking on a ham radio station and other equipment on battery operation.

The battery system must have the capability to be operational 24 / 7 - Therefore  I dont rely on just commercial power source. Even though my vehicle has a standard engine twelve volt battery system, last thing I would want to happen is drain the vehicle battery and not be able to start the vehicle. Also draining a standard lead acid battery reduces the number of recharges it can do, and also shortens its life capacity. It is intended  for short term high current drain as in starting the vehicle.

RV batteries on the other hand are designed to provide twelve volts at lower current drain over a longer period of time and not to be damaged if the RV battery is over discharged. RV batteries shouldnt be used as a vehicle starting battery. That is why I put in a separate battery system to operate my TS-480HX ham gear in my vehicle. Battery system used for all the ham radio gear operation in the vehicle was duplicated for the home hf system. The FT-1000MP used next to my easy chair in the living room was reconfigured so it wasnt using its internal AC to DC power supply. That keeps that internal supply isolated but available if some future circumstances would need it .... where the radio goes that internal power supply of course goes with it.

To protect the battery and to charge it properly, I use a PG40S Power Gate that uses the Anderson Power Pole connector standard. Here is a link to identify this unit properly, but of course shop around for your best deal.
When a car or RV battery is not being charged, its operating voltage will drop from the alternator level of around 13/14 bolts to around 12+ something ... and after some use to start dropping below twelve volts. Some HF gear might not transmit clean audio when the source voltage drops much below twelve volts. Check out your own gear, as this is not always the case ...... Alternators Are Not Heavy Current Drain Capable Like Batteries, they are short duty cycle for heavy current drain charging.

That covers an external source to operate / charge an hf radio operation battery system.

.... it is also important to pay attention to power distribution from the battery to the gear that is going to operate from that battery. RIGrunner utilizes a 13.8 VDC power panel with simple-to-use Anderson Powerpole connectors.... and these are the standard power connectors the ARRL recommends all amateur radio gear use. This allows compatibility among amateur equipment when used in the field and to be able to interface with other hams gear quickly and safely. There are several versions of the RIGrunner depending on how many connectors you want it to have to feed your expected gear load. I use this version: 40 amp 12 VDC continuous duty with 8 outlets with a sample link at:  and the manual is at:

In the mobile I use another gadget that is not needed on the base system, an APO3. It protects the battery from starting transients, and from over draining the starting battery if it is being used for the ham gear.That is because a vehicle system has a risk that the base station does not. If a vehicle has a bad starting battery and your operating from that battery, when starting the vehicle the battery doesnt protect the ham gear from the starting transients the starter system could have, especially if that starting system is going bad. The APO3 is a black box designed to prevent a vehicle battery from being discharged and damaged by a DC load. Typically it is used to switch a radio transceiver off 10 minutes after the vehicle is shut off. The APO3 is designed for 12 volt vehicle electrical systems with negative ground. It can switch up to 20 amps and carry up to 30 amps. The shutdown voltage can be set to one of four pre-programmed voltages (11.8, 12.1, 12.7, 13.05 volts) using two DIP switches; the shutdown delay can be set to one of four pre-programmed times (0, 5, 10, 20 minutes). The device is housed in a sturdy ABS plastic case.  The APO3 is ideal for use with mobile APRS / AVL stations. It allows the radio to transmit a few position reports after the vehicle is shut off before turning off the radio and GPS. This reduces clutter on the APRS / AVL channel and prevents the vehicle battery from discharging.

Connect the transceiver right across the battery, fusing all radio cable leads. Check out the information about  connecting transmitters right to the battery as detailed by W1ZR.

Previous mobile battery here was a GEL 70 a/Hr battery.

Replaced the 70 a/hr battery I used for 24/7 over the last six years with a 12 Volt Group 31 Gel AGM Werker Battery WKG12-100DT 100 a/hr from Batteriesplus.

Am considering a bit larger capacity battery for the base .... even thought about two six volt batteries hooked up in series. That way I could physically lift a 70 or 80 pound six volt battery and move it around. Limiting a 12 volt battery to that weight limits the capacity of the battery .... ugh

Well, that should cover how I operate full time from an RV battery be it the mobile or the base station.

73 from Bill - WD8ARZ

See my Geiger Counters Located in South Bend, Indiana at this
map ... my two stations are in the N.W. section of Indiana: