Leisure battery

[BerryT25]

Hi there

How long does a leisure battery last when not attached to a hook up (very new to this! Purchased our T25 in November and starting to get ready for our trips!)

Thank yoy!

[Jim San]

I don't have the answers but someone will and you'll need to offer more info;

how many Ah is the battery?
What are you powering etc

[MidLifeCrisis]

Welcome BerryT25 - and congrats on the purchase!

Get yourself over to 'General Chat' and introduce yourself - especially if you have fun pics of the van to show off!!
Also, add your vehicle type, fuel type, engine type to your signature (which you can change in 'User Control Panel') so when you post questions people can see what you have (... here endeth the sermon!!)

Ok - to the question ...... as already stated the length of time your leisure battery will last between chargings is dependant on its capacity which is measured in Amp-Hours (Ah) - so a 100 Amp-Hour battery can 'theoretically' give 10 Amps for 10 hours (or 5 Amps for 20 hours or 20 Amps for 5 hours etc) but most folks will suggest that you shouldn't discharge a battery past about 50% - so you can immediately half the capacity written on the battery.

So once you have that number you'll need to know how much current the stuff you are using in the van is going to draw - so a small interior light might only need 0.5 amps whilst a Propex heater will draw 2 amps, or if you have a massive stereo system running off the leisure battery or a TV/DVD player - then your demands on the battery will be much greater ...... so it's a bit of a 'how long is a piece of string' question !

Does your van have any way to warn you that your leisure battery is low ? If you have a Zig power panel for instance it has a warning LED when battery voltage is low .... but in short you'll need to know the capacity of your battery (should be written on it somewhere) and you need to know what sort of thing you are going to be running off that battery ....... hope that helps a little ......

[CovKid]

If I go 'off grid' its generally in Summer where I can last for 10-14 days but I'm only using low-draw items (LED lighting, Tesco Hudl, charging the phone). As said, a TV or Propex heater will draw far more and you'll need to take it for a good run every two days approximately - if the battery is a good one and in good order. I never ever use the stereo off grid. I've got a battery powered radio for such occasions. I don't use hookup at all so leaned towards low-draw items from the start.

There is solar I suppose but I find a spare battery and even running the engine for an hour does the job most of the time. If it costs a fiver (in fuel) in an emergency to charge the battery and have the Propex run the next night, so what.

[Ceecee85]

I've seen all the sums to work this out and it just confuses me!!! What I did was set the van up in "we're on an off grid trip mode" on the driveway- let the stereo run, had the interior lights on, phone charger plugged in, cooler box and other usual bits and pieces going. I checked the fully charged battery at the beginning and saw what happened to the voltage after an hour, two hours etc. It just gave me a rough clue as to how fast these electrical things sap power. Nothing very scientific but it gave me an idea as to the effect of having things turned on and meant I didn't have to get a calculator out. It also gave me a good excuse to sit in the van for the majority of the day getting some peace and quiet reading the papers and drinking beer.

[CovKid]

or....If it gets hot or makes a lot of noise, it'll cost you. Come to think of it that applies to most things in life.

[ghost123uk]

@ Ceecee85 = Cooler boxes usually draw a current too large to be of any practical use off a leisure (or main) battery. They commonly take about the same as leaving both your headlights on, plus they take ages to actually get cool. The wattage and / or current should be on a sticker somewhere on it. Just a heads up

Note to both of you re discharging leisure batteries. Never let them fall below about 11.5 Volts minimum, lower than that will damage them, making them much less effective at storing power. You can buy a little device that automatically prevents this from happening. Here are some = LINK (note = those cheap ones are fine but you need to wire them up in some sort of "project case").

[California Dreamin]

Think of your battery as a sink full of water.....a higher amp hour rating equals a larger sink with more water.

Now the discharge (how fast is the tap running)
As you can appreciate...the tap could be dripping (LED lighting) or full on (12 volt fridge). Working out just how fast the water is running (sink emptying) is just a case of adding up all wattage's of the consumers you have turned on.

But as John points out...never allow the battery voltage to drop less than 11.5 volts (approximately 20% charge) so that means you have only ever got 80% of the batteries capacity to use.

General rule is: unless you are on hookup or have large solar panels or a generator...avoid heavy consumers such as: a fridge, any form of heater ie hair dryer through an invertor etc and things like TV's & computers can be used but only for short periods.

Martin