How long can I go without electricity (plugging in)?

bikegirl

Hey there,

I have a 2015 TAB 320 S. The battery I have is a deep cycle which has: 

• 1500 Pulse crank amps, 1010 marine crank amps, 76 amp hours, 160 minute reserve capacity

I realize it depends on how much I use however I'm wondering how long it will last if I only use the LED lights and put the fridge on propane. I will have water at the site and NO electricity. I also need to make sure I don't run my battery down too low and I'm unsure of how long that would take?

Thanks!

P 

Pieshobbithouse

I have done some inverter systems so I have calculated loads and estimated run times. So here goes. 1)76 amp hours is really 35. Why? Because you do not want to draw down your batteries past 50% on a regular basis.2)add up you loads. They are listed for each item. The best way is to turn on all the gadgets you normally run and use an amp meter to measure the total draw. Google the formulas. But for example if your fridge draws 5 DC amp hours then it would last 7 hours. This is a simple example and if you read into the math your head will pop.
but it’s a good start.  

Dalehelman

This maybe over simplifying things but, the less you use the longer it lasts. Through your own experience is the best way to find out. 

pthomas745

JKJenn has worked all the amp usage for practically every electrical part in her Tab. Pieshobbithouse has the right idea about adding your usage up, and the amount of actual battery you can use. (Amp Hours is the important number.)  Jenn's spreadsheet is on her website ( and I'm sure it is in the forum somewhere, too).

The main thing to remember is the Tab is using up battery whenever the battery switch is "on", due to  the parasitic draw from safety systems. etc.    When I have to go into max conserve battery mode, I turn my battery switch off. This is her web site, and the whole thing it is well worth a read.  You can estimate yourself how many amps per hour the reading lights use.  (Jenn made it massively easy even for me.)

https://jenngrover.com/2015/11/guilty-as-charged-rv-battery-use-management/

WilliamA

Hey all,
I don't mean to add more complication but don't forget that as your battery draws down required amperage actually goes up.  The lower the voltage the more amperage you need to do the same work.  When I do my own calculations, I add 10%.  That makes it easier and account for other losses too.  

WilliamA

Tabaz

When I first got my T@B, I did a test to find as many sources of parasitic draw as possible. Two "big" ones were the Jensen entertainment center and the television.  I installed an inexpensive 12V rocker switch to turn off the Jensen, and simply pull the power plug from the television when not in use.

Freshaire

@Tabaz .  I would love to install the rocker switch you have to turn off the Jensen system, even if only to get rid of the blue glow it sends out at night.  I don't have any electrical experience.  Is this something I could attempt?  Is there a resource you know of that could guide me?

Thanks!

WilliamA

Tabaz said:

"When I first got my T@B, I did a test to find as many sources of parasitic draw as possible. Two "big" ones were the Jensen entertainment center and the television."

I'm curious as to how much draw you discovered.  While I have a T@G, the entertainment system is the same.  I've never had any issues with the drawdown but always like to gather data for future use.  In addition, I've not considered turning off the juice to the radio because I'd lose my presets and time.  Not a big thing but more fiddling.  I have also never found the light on the radio to be an issue either.  For the TV, which seems to be brighter for some reason, I just put a piece of vinyl tape over the light.  Knocks it down by 50% or more.

I also noticed that you must have pulled the door stays off?  Any thoughts on that?

WilliamA

RollingBnB

Freshaire said:

@Tabaz .  I would love to install the rocker switch you have to turn off the Jensen system, even if only to get rid of the blue glow it sends out at night.  I don't have any electrical experience.  Is this something I could attempt?  Is there a resource you know of that could guide me?

Thanks!

The blue display can be turned off using the two buttons on the left of the display

Verna

@RollingBnB, that feature was not available with the 2015 Jensen.  The only way to totally dim on mine is to have a separate on/off switch. Me, I just leave the bathroom door open when sleeping so the organizer on the door shields me from the light.

WilliamA

Occom's razor.  What Verna said...

DurangoTaB

@bikegirl...I say 2-3 days.  Do you have one of those cigarette plug volt meters?

ScottG

@Freshaire, the Jensen in my early model 2015 (built in December of 2014) does have the dimmer option, so it's worth checking yours specifically. Apparently that feature got dropped sometime mid-year.

Tabaz

I have a 2016 which does have the feature to completely turn off the blue lights. Even with them dimmed, the unit draws juice. I'm guessing any device that uses a remote control is always "on" even if no lights are activated. Can't recall the exact amp draw, but it was enough for me to eliminate it. installing a 12v switch can be accomplished by someone with basic electrical skills. Be careful with size of the switch - there is very little room in the Jensen cabinet.

bikegirl

DurangoTaB said:

@bikegirl...I say 2-3 days.  Do you have one of those cigarette plug volt meters?

Hi @DurangoTaB - I do have one of those. 

Freshaire

@ScottG Thanks.  I do not have the  dimmer option.  My primary reason for wanting the on/off switch is for parasitic draw purposes.  I do have a piece of cardboard over the panel now to block the light.  Guess I'm going to have to get an electrical book and start reading.

Homebodyatheart

@bikegirl my maiden voyage I unknowingly went two full days on battery and propane. I didn't know the power pole had a on/off breaker switch! I had no problems till I went to plug in some awning lights at the 110 outlet. I still had a good charge and lots of propane left after 4 days out. I also dry camped one weekend with tenting friends, no water other than my tank, no shore power and I did just fine. I use Luci solar lights inside and rarely use the led lights anyway. I'm sure I could go much longer. Good luck!