Shore Power And Battery Charge

Jimbo

If I were to plug in to shore power one day a week would it keep  my battery at a safe level?

jkjenn

Jimbo said:

If I were to plug in to shore power one day a week would it keep  my battery at a safe level?

Temperature fluctuations will impact this.

JandJ92010

I agree with Sandra, don't assume anything. Check the battery with a voltmeter. If you disconnect the battery while in storage, you won't have to charge it every week.

Jimbo

Do I have tg check on the battery itself or can I use one of those voltmeters that plugs into an interior outlet inside the camper?

Michigan_Mike

Yes, a plug in LED style voltmeter will work just fine.  

Another way to approach this are from some points I posted a few days back as follows:

I would probably consider the following:

1.  Battery Shutoff Switch  - I would consider mounting a shutoff switch to eliminate the parasitic drain and to help isolate your battery.

2.  Battery Charge - I normally charge up all of my equipment batteries around the house (e.g., lawn tractor, boat battery, etc.) in late fall after I am done using them.  I do not remove these batteries and since they are fully charged this tends to help them through the harsh winters here in Michigan.  I have been doing this for a long time and have never experienced any adverse effects, other than the normal battery replacement that is a result of extended use via age and deterioration.  

3.  Battery Tender -  Use a battery tender to maintain the battery.   

If you "do not" install a battery shutoff switch the trailer battery is eventually going to be drained via the parasitic drain, even after being fully charged for the season if you are unable to isolate it from the trailer's circuitry.  

And in as much as the voltage converter DOES maintain and float the battery charge the factory DOES NOT recommend that you keep it plugged into shore power on a full time basis.  The manufacturer says you CAN do this, but t's like anything else in preserving something and using it in moderation.  

If you have a convenient power source near the trailer I would consider using a battery tender and hooking up the metallic clips supplied directly to the battery and letting the tender maintain the battery over the winter months.  If you have a wet cell battery (non-sealed unit) just ensure that the cells are up to snuff water wise (use distilled water only) and refill cells as needed.  You could also charge the battery up fully in the fall, pull the fuse (or disconnect the battery completely) and call it good.  

RZRBUG

If you use a plug in meter, you need to be disconnected from any charging source -- shore power or TV.  Otherwise, it will read voltage being sent to the battery instead of the battery charge state.

Nomad

RZRBUG - Except for a solar source at night. Then it's reading current state - correct?

RZRBUG

Forgot about the solar.  The only solar I use is a 10-watt maintainer, and when I have it connected during daytime, it does affect the reading with the plug in meter, but I think you are probably right about nighttime readings.  I have never made a nighttime comparison.  I may just do that tonight.  Someone else with more solar experience can answer that better than I.

Nomad

I think I'm correct - Right now it's showing 13.8 under semi-bright sun. Once dark, it'll probably read 12.8.

mash2

Correct, PXLated.  When there is solar energy entering, the battery capacity is difficult to assess since the solar controller is varying the voltage coming in from the panels.  My controller has a night time function where the charger turns itself off and the output is solely battery.  Any other time, the battery may be receiving bulk, boost, float or equalization with amperage controlled by the controller.  Mine has set points for determining nighttime activity (which I have set to off).  At all other times, the voltage is influenced by the solar system so the readings reflect charger and battery combined voltage in the electrical system.  

Jimbo

so let me try again - and thanks for everyone's input - if I buy a cheapo voltmeter that plugs into the exterior or interior outlet of the T@B, without the shore power connected, the voltmeter will show the battery levels.  If low, plug into shore power for a day to recharge?  Lather rinse repeat on a weekly basis?

RZRBUG

Jimbo, if you're talking about this little gizmo, the answer is yes.

mash2

Yes.  With no other power source (charger or solar charger), it gives the voltage in the battery.  If you are hooked up to shore power or solar, it will indicate how much power from the combined sources (battery + charger) is flowing thru the system.  

Not trying to be technical, but when you use this, it is really reporting the voltage in the system, a system that includes battery and other charger sources.  At night with no external power source (solar or T@B controller), it will report the voltage of the system with only a battery powering it.   This will give you an estimate of the energy remaining in the battery (there is the table that indicates the % of battery left).  Remember not to go below 50% of capacity (12.05 V) though generally try to stay above 12.2 to 12.3 on a regular basis (something around 70%  assuming you have a lead acid battery).  

pcaddy

Is the inline fuse to the battery supposed to be a 30 amp or a 20 amp?

pcaddy

I plugged into shore line about an hour ago to try to charge battery -- when checking the 30 amp fuse after being plugged into shoreline about an hour -- the 30 amp fuse was very hot --

Michigan_Mike

Your battery fuse should be a 30 amp fuse.  

Jimbo

Thanks RZRBUG but where would I plug that gizmo in?

Nomad

Jimbo's - You plug that little monitor into the cigarette lighter plug in the T@B - mine's in the one above the sink.

Michigan_Mike

Jimbo said:

Thanks RZRBUG but where would I plug that gizmo in?

So you don't have a cigarette style plug in your trailer?  If not, do you have an LED plug in your trailer?  They do make a dual LED 12 V plug unit that you could easily wire into your system.  That way you could monitor your battery voltage when dry camping and you would not need the LED digital meter shown above.

RZRBUG

You're welcome.  It plugs into any 12V outlet (cigarette lighter type plug) that is installed past your trailer battery.  My T@B has just one such receptacle just to the left of the sink.  I understand some of the newer trailers have more than one.  I got mine at Wal-Mart in the automotive department where they sell batteries, but most places that deal in automotive parts/accessories will have them -- less than $20.