How long will my leisure battery last ??

[droodle]

I'm off to a festival this week and will be onsite from 6am weds til monday lunchtime so 5 1/2 days .. i have a 2 month old numax 110Ah leisure batt .. i hope to power the fridge mainly (waeco coolmatic) and occasional lights .. and charge the phone (crap iphone batt=daily) We usually turn the frige off at night also.

How long do you think the batt will last ?

i also have a faulty willingon kit so all this will also drain the starter batt as well (jump leads packed)

Will starting the engine halfway through the weekend (won't be able to go anywhere) and running it for say 30 mins have much impact in extending the charge ? Or not worth the pollution ?

cheers.

[stilldesperate]

As no-one else has taken this on, I'll have a go....

I've just done a similar time in the van, where i couldn't run the engine much. The fridge will kill the LB, and I would expect the 30 min charge won't keep the LB topped up.

Here's what I do:

1. Only run the fridge 1hr a day. freeze milk and water/fruit juice at home to put in the fridge, cools everything else in there, and takes a couple of days to thaw in mine.
2. Try to be independent of cooling, (I've just bought a vacuum packer for trips away (£15 on fleabay), meat vacuum'd will last 5 days easily without a fridge, skimmed milk lasts loads longer than full fat, beer cans in a bowl, with a wet towel over cools pretty well)
3. Turn the phone off except for (say) 1 hr each day - tell anyone who needs to speak this. You can pick messages up during this hour.
4. Buy a cheap lantern, to save the LB.

Hope this helps,

SD

[Alison01326]

I'm not that electrically savvy but does a fridge not draw more power being switched on than it does while running?

And can you get a solar charger for your iPhone or a wind-up one? I have a wind up one for mine (not an iPhone) which gives me about half an hour of oomph which is enough to check texts and messages (apart from checking on my dad every night, I don't use the phone if I am on holiday).

As SD says, a cheap lantern or other battery / wind up lighting will save the leisure battery too. I don't use the interior lights in the Bongo at all - just three hook on round LED lights from B&Q. I hang them over the grab handles. We've also got a couple of head torches.

[mikexgough]

Your Coolmatic will use around 15 amps per day from your Battery.... Your battery will give you 80% capacity as a rule of thumb..... 5 days on the fridge and it's had it......
Take some advice from previous posters with torches and I guess if you have at least one or maybe 2 frozen meals etc in a stand alone cool box...(transfer to coolmatic to keep that cool inside so the compressor doesn't run) then you might be okay...

[TechnoTurkey]

I think you'd actually be ok for most of the time, maybe assume you will have zero left for the last night as a worst case scenario.

If the battery gives you 80% of it's capacity then that would be 88 amps to play with. If the fridge uses roughly 15 amps per day (based upon all day) then that would be almost six days worth, and that is forgetting that you would be turning it off at night and also potentially drawing current from the starter battery.

The draw from the iphone would be negliable and if you spairingly use LED lights then they won't draw too much either.

Another good tactic is to put the fridge on full blast when you are driving to the festival as that wont take power from the battery if the charging side of the circuit is functioning correctly and will lower the residual temperature of the fridge and the contents of it to give you a good starting point for the weekend.

[haydn callow]

Beware of running your LB down below 10.5 volts........it won't do the battery any good and when you do start the engine there is a danger you will "blow" the main 40/50 amp fuse as the alternator will try to push out loads of amps to recharge it......this happens to quite a few peeps at every bash.
Get a cheap volt/multi meter and measure the LB twice a day.....if it drops below 11 volts I would stop using it.

[TechnoTurkey]

The Waeco fridges will stop drawing current before it get's too low, not sure at exactly what point this occurs of the top of my head.

[droodle]

Wow a real mix of replies from 1 hr a day to several days .. i guess the only thing to do is to take it all on board and see how we go !

One i did think tho was that leisure batteries were designed to be run flat - and then recharged next time the engines on.

I'll report back how we go !!

[dave_aber]

Just done the same last week at Download festival. Did a test run (went away offshore) and left the L/B on, powering a fridge full of beer for 4 days. When I returned, the fridge was still running, contents cold, L/B still OK (didn't check the voltage). Drove home, and then off to Donnington. Good long 550 mile drive split by a 5-hour overnight hotel stop. So, Friday morning around 10am parked up and engine off.

L/B is a new 100aH Numax. Fridge is a Vitrifirgo 42L with an external compressor.

The books say that the fridge draws a nominal 1A whilst running. So, 24aH every 24Hrs. In theory about 4 days to use 80aH capacity from the 100aH battery.

In practice, with us in and out of the fridge every 20 mins or so, re-loading warm cans into it the consumption was more than 1a.

Sunday morning, checked the fridge to find that the ice (in the ice tray, for the JD & Crabbies cocktails) had melted. Fridge was not running. Battery voltage was 11.55v. Presumably the Vitrifrigo had cut out to save running the battery down too far (nice feature). Mobile phone charger was still charging OK. I had the phone plugged in all night each night (HTC Desire - also needs an iphone style charge every night).

Ran the engine for about 20 mins. LCA was complaining for about 10 mins of this - coolant level OK - which is to be expected.

After 20 mins, L/B voltage was reading 13.8v with the engne running. 12.4v with it stopped. Left the engine off for the rest of Sunday, still cans of beer going in/out about every 20 mins, then phone on charge overnight.

Monday morning, L/B was just under 12v, fridge still running, phone still working, and drove home.

[droodle]

Cheers dave that sounds more like it .. constantly stocked with beer

[dave_aber]

We could have probably managed the beer stocks better, pre-cooling the 'next ones' on a bucket or something - but as the consumption progressed we were less bothered by the temperature and less inclined to do any actual thinking.

I was quite impressed how much life I got back by running the engine for 20 mins on Sunday morning.

[madmile]

If it was me, I would use the jump leads on site for say 20 mins each day to connect the LB to the Starter Battery with the engine running. This will probably top it up enough for you to camp as normal provided you start with a fully charged LB.
If the relay is not working, just disconnect it for now ( just pull the main fuse). Every thing else should work as usual, and you should get 2-3 days from the battery. If you have jump leads already, then your sorted - just disconnect them before once you have stopped the engine. Just a thought, but if the relay is stuck on, then you could just pull the fuse when you stop, and put it back in when you run the engine for a top up.

[mikeonb4c]

As no-one else has taken this on, I'll have a go....

I've just done a similar time in the van, where i couldn't run the engine much. The fridge will kill the LB, and I would expect the 30 min charge won't keep the LB topped up.

Here's what I do:

1. Only run the fridge 1hr a day. freeze milk and water/fruit juice at home to put in the fridge, cools everything else in there, and takes a couple of days to thaw in mine.
2. Try to be independent of cooling, (I've just bought a vacuum packer for trips away (£15 on fleabay), meat vacuum'd will last 5 days easily without a fridge, skimmed milk lasts loads longer than full fat, beer cans in a bowl, with a wet towel over cools pretty well)
3. Turn the phone off except for (say) 1 hr each day - tell anyone who needs to speak this. You can pick messages up during this hour.
4. Buy a cheap lantern, to save the LB.

Hope this helps,

SD

Excellent post - a man after my own (well, before my own in truth)

Didn't know about vacuum packed meat. V. interesting. Same technique could be used I guess for precooked stews etc. esp. as they are sterile after cooking. I buy Cravendale milk as being a lot longer lasting. Choose beer that is nice to drink when not being ice cold (Cans of Tanglefoot do me). As SD says, if you freeze the meat, sausages etc they become edible cooler packs and don't waste space. You can also get some seriously well insulated coolboxes.

Personally, I've found I like to be as free as possible from dependancy on electricity, even from an LB. I'd like to experiment more with evaporative cooling as this should extend the time stuff stays cool in a coolbox.

[mikexgough]

I'd like to experiment more with evaporative cooling as this should extend the time stuff stays cool in a coolbox.

Try one of these......... http://www.vwcurtains.com/easicool.php I used one many years ago .....yes they do work,not as efficient as a compressor fridge but keeps your dairy & meat stuff fresh........if you freeze things too as has been suggested..... jobs a good 'un

[dobby]

My leisure battery lasted 5 years, whats all the fuss?