Will leaving engine on tick over charge LB

[Iwannabongo]

Hi all,
I have been trying to search for an answer, but can't find much info.
Will leaving the engine running on tick over for 1/2 an hour charge the LB very much, or would this be a waste of time.
I am just asking as I am off to Grand Prix in a few weeks time for 5 days and will not be able to go off for a drive and obviously want chilled beers without paying £5 a pint.
cheers in advance

[daveblueozzie]

It depends on how good your main battery is, the split charge relay charges your main battery first, then it charges the LB.
If your main battery is OK then don't see any problem, why not get a meter to check the condition and how much it charges .

[Iwannabongo]

It depends on how good your main battery is, the split charge relay charges your main battery first, then it charges the LB.
If your main battery is OK then don't see any problem, why not get a meter to check the condition and how much it charges .

I have a brand new elecsol that I have used a few times, but not sure about the SB
If I give my SB and LB a full charge before setting off, then I presume this would help a bit?
I just want to know if a 1/2 hour tick over would charge enough for a few more hours of cold beers?
thanks again

[missfixit70]

It should be ok, what are you using to cool them? a normal 12v cool box will sap the battery in no time & you may struggle, but if you got a compressor fridge, you should be ok. 3 way gas fridge would be the way to go otherwise, not that expensive, work really well, I had one I used for a couple of years that I'd got out of a folding caravan from freecycle, not the most portable bit of kit, but if you're setting up camp for 5 days you're not going anywhere once set up used to turn it off at night or even on lowest setting it'd start freezing stuff.

[Iwannabongo]

It should be ok, what are you using to cool them? a normal 12v cool box will sap the battery in no time & you may struggle, but if you got a compressor fridge, you should be ok. 3 way gas fridge would be the way to go otherwise, not that expensive, work really well, I had one I used for a couple of years that I'd got out of a folding caravan from freecycle, not the most portable bit of kit, but if you're setting up camp for 5 days you're not going anywhere once set up used to turn it off at night or even on lowest setting it'd start freezing stuff.

I have a Waeco compressor fridge and a coolbox.
I never realised that a coolbox would use more power though
Is that just because it is constantly running, where as the fridge turns itself off?
thanks

[missfixit70]

It's to do with how they work, the peltier unit on a coolbox is cheap to make but is heavy on current use, stick with the compressor fridge if you're not on hook up. lots of frozen stuff in the cool box may give you a couple of days of coldness, but don't plug it in if your engine isn't running.

[Iwannabongo]

It's to do with how they work, the peltier unit on a coolbox is cheap to make but is heavy on current use, stick with the compressor fridge if you're not on hook up. lots of frozen stuff in the cool box may give you a couple of days of coldness, but don't plug it in if your engine isn't running.

Blimey, thanks for that. You learn a lot on here.
Do you have any idea how long a Waeco fridge will run for off a fully charged 100amp elecsol LB?
I won't be really using any other stuff apart from Electric blinds and led lighting.
Sorry for all the Q's, but I have only ever used it for 2 days without driving off.
thanks again

[missfixit70]

Depends how warm it is, how often you open it, how warm the beers are that you put back in to cool & what else is running off the LB Very much a "how long's a piece of stirng kinda question", but you should get a few days out of it.

[g8dhe]

You ought to get around 4 days of fridge alone without it being opened, but with other demands, lights, blinds, radio etc. I would suggest a Max of about 3 days depending how much you use it of course, every time you open the door all the cold air will drop to the floor, and the new air has to be cooled down again.

[dvisor]

It's to do with how they work, the peltier unit on a coolbox is cheap to make but is heavy on current use, stick with the compressor fridge if you're not on hook up. lots of frozen stuff in the cool box may give you a couple of days of coldness, but don't plug it in if your engine isn't running.

Blimey, thanks for that. You learn a lot on here.
Do you have any idea how long a Waeco fridge will run for off a fully charged 100amp elecsol LB?
I won't be really using any other stuff apart from Electric blinds and led lighting.
Sorry for all the Q's, but I have only ever used it for 2 days without driving off.
thanks again

It just so happens I can give you at least some idea! I've been having some problems with my Elecsol over the past year and finally got round to doing some tests. I was finding that my Waeco CF25 would only run a few hours before the battery got so low that the compressor would be constantly kicking in and then shutting down immediately (to protect the battery discharging completely). I thought the Elecsol was dodgy, so I took it out over the weekend, charged it up fully, then measured the drop over 24 hours. Negligible, so the battery seems OK. I then fully charged it again, and connected only the Waeco fridge to see how long it would run before the voltage got so low that it started cutting out again. It was certainly running 48 hours later, but it stopped at some point within the next 24 hours (I had to go away so couldn't keep an eye on it). So, with nothing else connected, my Waeco kept going for between 48 and 72 hours on my elecsol. Of course, I wasn't opening and closing the fridge, so in reality it wouldn't last as long. Also your lights will further reduce it. Your cabling also needs to be good, otherwise you'll find that voltage drop may seriously affect it (as I have found in the past). The fridge was set to 0C during my tests ( but seemed to spend much of the time at -3C ), and was running in a warmish shed. Not very scientific, but hope it helps.

[Iwannabongo]

It's to do with how they work, the peltier unit on a coolbox is cheap to make but is heavy on current use, stick with the compressor fridge if you're not on hook up. lots of frozen stuff in the cool box may give you a couple of days of coldness, but don't plug it in if your engine isn't running.

Blimey, thanks for that. You learn a lot on here.
Do you have any idea how long a Waeco fridge will run for off a fully charged 100amp elecsol LB?
I won't be really using any other stuff apart from Electric blinds and led lighting.
Sorry for all the Q's, but I have only ever used it for 2 days without driving off.
thanks again

It just so happens I can give you at least some idea! I've been having some problems with my Elecsol over the past year and finally got round to doing some tests. I was finding that my Waeco CF25 would only run a few hours before the battery got so low that the compressor would be constantly kicking in and then shutting down immediately (to protect the battery discharging completely). I thought the Elecsol was dodgy, so I took it out over the weekend, charged it up fully, then measured the drop over 24 hours. Negligible, so the battery seems OK. I then fully charged it again, and connected only the Waeco fridge to see how long it would run before the voltage got so low that it started cutting out again. It was certainly running 48 hours later, but it stopped at some point within the next 24 hours (I had to go away so couldn't keep an eye on it). So, with nothing else connected, my Waeco kept going for between 48 and 72 hours on my elecsol. Of course, I wasn't opening and closing the fridge, so in reality it wouldn't last as long. Also your lights will further reduce it. Your cabling also needs to be good, otherwise you'll find that voltage drop may seriously affect it (as I have found in the past). The fridge was set to 0C during my tests ( but seemed to spend much of the time at -3C ), and was running in a warmish shed. Not very scientific, but hope it helps.

Yeah, that helps loads.
I will keep the fridge on about 5c, so will not be cutting in too much.
I also have another old LB (on its last legs) that I will probably take, which might give me another day of chilled beers
Thanks everyone for your input, much appreciated

[mister munkey]

That's not a bad thread in 90 minutes from start to now, I've learnt a fair bit there too!!

[missfixit70]

I also have another old LB (on its last legs) that I will probably take, which might give me another day of chilled beers

No need to lug another (especially iffy) battery, just do what you were going to, run it for half an hour or so a couple of times during the 5 days you're there

[maxi_77]

Running the engine at tickover may not put all that much back into your battery, automotive alternator regulators are very unsmart and assuming you took 50 amp/hours out of the battery would probably need several hours to get most of it back in, yes the alternator can chuck out lots of amps but the way the regulator works it cuts down to just a few amps within minutes. Just think, 50 AH needs 5 hours at 10 amp charging current. Have you looked at either getting and electric hook up so you can run a battery charger or even hiring a suitcase generator to do the job.

On how much your Waeco uses I would suggest somewhere between 30 and 40 AH per 24 hours. You may cut this down a bit by adding external insulation but keep the air vents clear. And remember taking more that 50% out of a LB is not good for it and I think the Waeco has a cut out to protect the battery

Have a good time

[dave_aber]

As a comparison, last year at the Download festival my fridge was dead on the 4th morning (Sunday). Checked the L/B, and it was around 10.5v (IIRC) - just below the fridge's cut-off level. So, I ran the engine for 20 mins. By the following morning, the fridge was still running, and the L/B just above the cut-off level once more.

So, for me at least, 20 mins at tickover gave me a day's more fridge.

110 aH L/B, Vitrifirgo 42L compressor fridge, warm days, lots of beer and air in and out of the fridge over the period.

I'm departing on the same voyage again this afternoon, but I have added 4 freezer packs into the freezer bitty. Once we get on site and are in & out of the fridge a lot I'll move them down into the fridge bit to help keep it cold.

Hope that helps
Dave