Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Newmar Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 05-26-2012, 12:35 PM   #1
Senior Member
 
litespeed's Avatar
 
Join Date: Jan 2007
Location: Gainesville, GA
Posts: 162
battery calculations?

I am trying to use my inverter continuously so that my TV antenna doesn't shut down and require rebooting...and our small load stuff will stay up. Then run the generator 4-5 hours a day to recharge.

I am not sure if I have a battery problem or just don't know how to recognize normal operation. I have 4 6volt batteties

When the generator gets to float level and I shut it off. The inverter screen says my batteries are at about 12.7 volts. With a load of around 25 amps..per the inverter screen...the battery voltage drops pretty quickly....down into the mid 11's within a few hours or so.

The 25 amp load is produced by a tv, a direct tv receiver, a few cell phone chargers, a play station, a computer charger...nothing much more than that.

Does all of the above seem within normal parameters or are my batteries discharging faster than normal?
__________________
Jay, Lee, Lucy(Jack Russell Terrorist)& Marley(Lucy's buddy)
2010 Dutch Star 4010
Harley on a hydralift/jeep behind
litespeed is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-26-2012, 12:56 PM   #2
Senior Member
 
wb7auk's Avatar
 
National RV Owners Club
Join Date: Feb 2012
Location: Spokane Valley, Wa
Posts: 1,987
Quote:
Originally Posted by litespeed View Post
I am trying to use my inverter continuously so that my TV antenna doesn't shut down and require rebooting...and our small load stuff will stay up. Then run the generator 4-5 hours a day to recharge.

I am not sure if I have a battery problem or just don't know how to recognize normal operation. I have 4 6volt batteties

When the generator gets to float level and I shut it off. The inverter screen says my batteries are at about 12.7 volts. With a load of around 25 amps..per the inverter screen...the battery voltage drops pretty quickly....down into the mid 11's within a few hours or so.

The 25 amp load is produced by a tv, a direct tv receiver, a few cell phone chargers, a play station, a computer charger...nothing much more than that.

Does all of the above seem within normal parameters or are my batteries discharging faster than normal?
What is the amp hour rating of the 6 volt batteries?
How old are they and have you load tested them to see what shape they
are in?
__________________
Art
1999 Trade Winds 7371 Cat 3126B w/current upgrades
1990 D 250 Dodge Ram Cummins Turbo
wb7auk is offline   Reply With Quote
Old 05-26-2012, 01:59 PM   #3
Senior Member
 
Join Date: Jul 2010
Posts: 299
Quote:
Originally Posted by litespeed View Post
I am trying to use my inverter continuously so that my TV antenna doesn't shut down and require rebooting...and our small load stuff will stay up. Then run the generator 4-5 hours a day to recharge.

I am not sure if I have a battery problem or just don't know how to recognize normal operation. I have 4 6volt batteties

When the generator gets to float level and I shut it off. The inverter screen says my batteries are at about 12.7 volts. With a load of around 25 amps..per the inverter screen...the battery voltage drops pretty quickly....down into the mid 11's within a few hours or so.

The 25 amp load is produced by a tv, a direct tv receiver, a few cell phone chargers, a play station, a computer charger...nothing much more than that.

Does all of the above seem within normal parameters or are my batteries discharging faster than normal?
That sounds like it's about the way mine work, I use a Cpap and I turn the inverter on at night, even with a full charge on the batteries the batteries won't run the inverter/cpap all night. I think my batteries should last all night but I'm not smart enough to figure it out. If I leave the inverter off the batteries are fine the next morning and will run the overhead fans all night and day. Since I'm not smart enough to figure it out (basically I'm just too lazy to fool with it) I use a Honda 2000 generator to supplement my batteries. I can fill the generator with one gallon of gas at night, crank it up and it'll run all night long charging my batteries and running my cpap. When I wake up the next morning I turn the generator off.

PS. It only take a couple of minute for my directtv receiver to update after I remove the power from it and put power back to it.
__________________
Sonny, Anita and Phoebe
2005 MADP 4304, 2005 Ford Crew Cab F150 toad, 2009 Harley Ultra Classic
harleyman134 is offline   Reply With Quote
Old 05-26-2012, 02:27 PM   #4
Senior Member
 
Mr_D's Avatar
 
Country Coach Owners Club
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 37,725
We have four Interstate U-2200's, they run the TV's, the furnace, the satellite box, the controls for the refer (refer on gas), the U-Line ice maker, the storage bay freezerm my CPAP and everything else we might turn on except the Advantium microwave/convection oven. Sometimes we are down to 11.9 volts in the morning though.
__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft, HWH Active Air
Charter Good Sam Lifetime Member, FMCA,
RV'ing since 1957, NRA Benefactor Life, towing '21 Jeep JLU Rubicon Ecodiesel
Mr_D is offline   Reply With Quote
Old 05-28-2012, 07:42 AM   #5
Senior Member
 
Lug_Nut's Avatar
 
Join Date: May 2005
Location: British Columbia
Posts: 3,838
Well, you say you are down to 11.9 by the morning, but that it not really the true reading of the batteries. This is due to the current load on the batteries. The true state of the batteries can only be read with all loads off and a standing reading taken. These batteries would probably read 12.3 if all loads were removed and let stand for a short period.

This is applied to all auto generator starting systems. For example if you set an auto start at 12.3 vdc, the generator would be starting every time you applied any reasonable load. 12.3, by the way is 50% charge, a state that you do not want to go below. So, all auto generator starting systems are usually set to start at 11.7 to 11.9. The former being more used.

Additionally it would be good to read your battery state at the batteries with a multi-meter. This would be far more accurate as there is no wiring voltage loss.

I guess what I'm saying, is your batteries may be working correctly. If you have an issue, there is a chance your charging system may not be fully charging your batteries. This is quite common.

I had an '02 DSDP and experienced similar issues. I replaced the charger/converter with a better unit. It was like night and day. The batteries charged fully. It was like I installed twice the size battery bank.

Anyway, hope this helps.

Peter
__________________
Peter - Doctor of Mixology
KADB 2013
Lug_Nut is offline   Reply With Quote
Old 05-28-2012, 09:21 AM   #6
Senior Member
 
Join Date: May 2009
Location: Bluff Dale, TX
Posts: 624
You should only use about 50% of the battery capacity. Two 6v batteries have about 220 amps capacity, four have about 440 capacity. Using half of that gives you 220 amps available.

Knowing your available available amps the length between charges is dependent on the amps being used. 220 amps with a load of 25 amps should give you about 8.8 hours of use before recharging.

Reducing the load or adding more batteries will give you a longer run time.

You could reduce the generator run time by just charging to about 80%. This should only take about an hour. A run in the morning and a run in the evening. About once a week charge up to the float stage like you do now.
__________________
Most RV batteries live a long and useful life, some are murdered.
2000 National Sea Breeze F53
1998 CRV Toad
garym114 is offline   Reply With Quote
Reply

Tags
battery



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 09:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.