RV.Net Open Roads Forum: Tech Issues: Question: Truck Battery Bank for Shore Power

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Question: Truck Battery Bank for Shore Power

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 2  
Next
Sponsored By:
Dave in Central NC

Broadway, NC

New Member

Joined: 06/29/2020

View Profile


Offline
Posted: 06/29/20 09:26pm Link  |  Quote  |  Print  |  Notify Moderator

Based on some back-and-forth with my original post, I've redefined my problem.

1. Situation: I'm trying to use the battery bank on my truck for shore power for my travel trailer. I want to be able to use the battery bank on my truck to run low-draw AC appliances while dry camping.

1.1. Battery Bank: On the truck I have three deep cycle batteries in parallel connected to an inverter. These are not tied into the truck's alternator. I use a Schumacher battery charger to keep them topped off.

1.2. Wiring from Camper to Inverter: First, the camper's shore power cable plugs into a 30Amp RV to 15/20Amp pigtail adapter. Second, a 20-amp 10-gauge generator cord plugs into the pigtail adapter and goes to the back of the truck. Third, the generator cord plugs into a 15A to 20A adapter, and then is plugged into the inverter.

1.3. Inverter Information: My set up works with an 800W inverter that outputs 120 volts. My set up does not work with my 2000W inverter that outputs 115 volts.

2. Problem: I want to use my 2000W inverter to provide shore power to my camper. Seeing that the 800W inverter that outputs 120V works and the 2000W inverter that outputs 115V does not, is there anything I can do to get the 2000W inverter to work?

2.1. The inverter I'm asking about is a Whistler Pro-2000, it outputs 115 volts (modified sine wave). When I connect the shore power cable to it, the RV gets power for a second, then the inverter goes into alarm mode (audible alarm, light blinking red-green-red-green, and power from inverter cuts off).

2.2. Last night, I was asked whether my inverter outputs 120 volts. I looked and the labeling on the inverter clearly states it outputs 115V (the Whistler Pro-2000). I also have an 800W inverter in the house that outputs 120V. When I tried using this inverter for shore power, I was successful in using truck's battery bank to provide power to the RV.

Thanks,
Dave

* This post was edited 06/30/20 08:49am by Dave in Central NC *

corvettekent

Marysville, WA

Senior Member

Joined: 09/21/2014

View Profile



Good Sam RV Club Member

Offline
Posted: 06/29/20 09:45pm Link  |  Quote  |  Print  |  Notify Moderator

Are the three deep cycle batteries fully charged?
Is the inverter turned on?
Is there 120 volts at the output of the inverter?


2007.5 GMC Dually EC/LB, LMM. Banks IQ, Speed Brake, Six Gun. B&W Turnover Ball, Companion Hitch, Amp power steps. Hadley Air horns.

2004 32' Carriage 5th wheel. 480 watts of solar MPPT and four 6 volt batteries. Samlex 2,000 watt Pure Sine Wave Inverter.


Dave in Central NC

Broadway, NC

New Member

Joined: 06/29/2020

View Profile


Offline
Posted: 06/29/20 10:12pm Link  |  Quote  |  Print  |  Notify Moderator

Fully charged? Yes. Inverter on? Yes. 120 volts? No. I have a 2,000W Whistler inverter that outputs 115V.

Dave in Central NC

Broadway, NC

New Member

Joined: 06/29/2020

View Profile


Offline
Posted: 06/29/20 11:13pm Link  |  Quote  |  Print  |  Notify Moderator

So it appears to be an issue with the inverter (and I would imagine the output voltage). I just tried my 800W inverter that outputs at 120V and it worked fine.

valhalla360

No paticular place.

Senior Member

Joined: 08/19/2009

View Profile



Posted: 06/30/20 04:45am Link  |  Quote  |  Print  |  Notify Moderator

Are they really deep cycle...or are they the combo batteries (which are really just starting batteries with a different label). 12v deep cycle batteries are hard to find and expensive. Most people parallel 6v golf cart batteries which are legitimate deep cycle batteries.

What size cables and how long are they connecting the batteries to the inverter? 2000w is about 170amps, that takes a pretty thick battery cable and will kill a moderate battery bank pretty quick.

How are you replacing the power draw? The standard truck alternator will only put out the rated output for a short time and then it drops back significantly.

Does the inverter have a fuse/breaker? That would be a simple answer.


Tammy & Mike
Ford F250 V10
2008 Copper Canyon 5er
Catalac Catamaran 34'
Full Time spliting time between boat and 5er


wa8yxm

Wherever I happen to park

Senior Member

Joined: 07/04/2006

View Profile


Offline
Posted: 06/30/20 06:05am Link  |  Quote  |  Print  |  Notify Moderator

Is the inverter a PSW or MSW
DO you have any kind of "Surge Guard" or Progressive Industries EMS? or competitor's product.

Some of those look at the wave form and will not pass MSW inverters.


Home is where I park it.
Kenwood TS-2000 housed in a 2005 Damon Intruder 377


Dave in Central NC

Broadway, NC

New Member

Joined: 06/29/2020

View Profile


Offline
Posted: 06/30/20 07:45am Link  |  Quote  |  Print  |  Notify Moderator

I have a Whistler Pro-2000W inverter that produces a modified sine wave.

Here's verbiage about this from the WhistlerPro200 owner's manual:

Whistler inverters work in two stages. During the first stage,
the DC to DC converter increases the DC input voltage from
the power source (e.g. a 12 volt battery) to 145 volts DC. In
the second stage, the high voltage DC is converted to 110
volts (60 Hz AC) using advanced power MOSFET transistors
in a full bridge configuration. The result is excellent overload
capability and the capacity to operate difficult reactive loads.
The output waveform resulting from these conversions is a
"quasi-sine wave" or a "modified sine wave" as shown on
below. This stepped waveform is similar to the power generated by
utilities and has a broad range of applications.
The modified sine wave produced by the Inverter
The modified sine wave produced by your Whistler inverter
has a root mean square (RMS) voltage of 110 volts. The majority
of AC voltmeters measure RMS voltage and assume that the
measured waveform will be a pure sine wave.
Consequently, these meters will not read the RMS modified
sine wave voltage correctly and, when measuring your Whistler
inverter output, the meters will read about 20 to 30 volts too
low. To accurately measure the output voltage of your inverter,
use a true RMS reading voltmeter such as a Fluke 87, Fluke
8060A, Beckman 4410, Triplett 4200 or any multimeter identified
as "True RMS."

Dave in Central NC

Broadway, NC

New Member

Joined: 06/29/2020

View Profile


Offline
Posted: 06/30/20 08:18am Link  |  Quote  |  Print  |  Notify Moderator

Answering valhalla360's questions.

But before I do, this update.

The inverter I'm asking about is a Whistler Pro-2000, it outputs 115 volts (modified sine wave). When I connect the shore power cable to it, the RV gets power for a second, then the inverter goes into alarm mode (audible alarm, light blinking red-green-red-green, and power from inverter cuts off).

Last night, I was asked whether my inverter outputs 120 volts. I looked and the labeling on the inverter clearly states it outputs 115V (the Whistler Pro-2000). I also have an 800W inverter in the house that outputs 120V. When I tried using this inverter for shore power, I was successful in using truck's battery bank to provide power to the RV.

On to valhalla360's questions...

Question 1: Are they really deep cycle...or are they the combo batteries (which are really just starting batteries with a different label). 12v deep cycle batteries are hard to find and expensive. Most people parallel 6v golf cart batteries which are legitimate deep cycle batteries.

Answer 1: Batteries are combo batteries.


Question 2: What size cables and how long are they connecting the batteries to the inverter? 2000w is about 170amps, that takes a pretty thick battery cable and will kill a moderate battery bank pretty quick.

Answer 2: The cables that connect the inverter to the batteries are 2AWG and about 30 inches long.


Question 3: How are you replacing the power draw? The standard truck alternator will only put out the rated output for a short time and then it drops back significantly.

Answer 4:
I use a Schumacher battery charger to recharge the batteries. The battery bank is not tied into the truck's alternator. House current --> battery charger -->batteries.


Question 5: Does the inverter have a fuse/breaker? That would be a simple answer.

Answer 5: Inverter has an internal fuse, no breaker.

* This post was edited 06/30/20 09:32am by Dave in Central NC *

Tom_M

New Hope, MN

Senior Member

Joined: 04/24/2011

View Profile


Offline
Posted: 06/30/20 08:57am Link  |  Quote  |  Print  |  Notify Moderator

Some inverters do weird things with the neutral and ground. Try a two prong adapter like the one below:

[image]


Tom
2005 Born Free 24RB
Towing 1978 VW Bug convertible
Minneapolis, MN


BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 06/30/20 09:29am Link  |  Quote  |  Print  |  Notify Moderator

Want does "works" mean? You are getting low voltage alarm and shut down with the 2000w but not with the 800w.

Are you trying the 2000w with a big load like the water heater on electric, but not when using the 800w? Does the 2000w "work" with the same load as the 800w?

If all it is that makes the 2000w not "work" is a big load, you can reduce the voltage drop so it stays above 11v under load, by using fatter wire between inverter and battery bank, balancing the bank better with no "downstream batteries", and making sure the batteries are well charged up (needs an hydrometer for that to be sure)

BTW that red plug above is not supposed to be used in the Code ISTR.


1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
See Profile for House electronics set-up.
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 2  
Next

Open Roads Forum  >  Tech Issues

 > Question: Truck Battery Bank for Shore Power
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2020 CWI, Inc. © 2020 Good Sam Enterprises, LLC. All Rights Reserved.