Leisure Battery whilst Wild Camping

[Birdy67]

Glad to see you are full of confidence and rearing to go.
What's the worst that could have happened?
A bottle of water and a torch would have taken care of all your short term needs.

Very true but as we had guests who are potentially future Motorhomers we wanted to make sure they were impressed with how things worked. Thankfully they went away full of enthusiasm so all was good. For my part it was a good lesson in how things worked when not connected so I'll be more confident of doing some wild camping or not bothering to search for EHU sites the next time we have a weekend away. Overall a very successful weekend.

 

[Threeracers]

It really depends how accurate your dispaly is. My Burstner dispaly reads 0.2 below the actual voltage of the battery. I know this as I check the battery level with a multimeter. Might be worth getting one. You are OK down to 50% of battery capacity which is generally about 12 volts. (varies according to battery type. You can look up some charts on the internet but this is an example.

Don't forget - display will read lower when in use. You can only tell the true state of the battery after an hour of no use. When solar is charging it will read higher than actual. Telling the actual state of the battery at a single point in time is quite difficult. 4am is a good time to check it (assuming you haven't used it the the prior hours or 2)

View attachment 798790

So would you just double those voltages for a 24 volt battery?

Mark

 

[PeterCarole29]

It might be worth reading some posts on surge protectors or at least be aware of the posibilities and wether it would effect any electrics in your van . As its your first trip to france

 

[autorouter]

So would you just double those voltages for a 24 volt battery?

Yes

 

[autorouter]

A bottle of water and a torch would have taken care of all your short term needs.

And a small power pack to keep the phone charged.

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[Threeracers]

Yes

The reason I ask is that I was sent a similar guide to capacity when I installed my batteries but with quite different numbers.

12.6 volts on that indicates 100% but on my guide 25.2 volts is a little over 14%.

 

[Pablo19]

Just to clarify a point from earlier in the thread, the Phantom app is definitely the starter battery, I made a similar assumption to my cost! If you have Truma iNet that displays leisure battery either on bluetooth or through the text comms.

 

[autorouter]

The reason I ask is that I was sent a similar guide to capacity when I installed my batteries but with quite different numbers.

12.6 volts on that indicates 100% but on my guide 25.2 volts is a little over 14%.

VXman's chart is for a lead-acid battery. Your chart is for a lithium (LiFePO4) battery. The corresponding chart for a 12V LiFePO4 battery has voltages exactly half of your 24V chart.

 

[Threeracers]

VXman's chart is for a lead-acid battery. Your chart is for a lithium (LiFePO4) battery. The corresponding chart for a 12V LiFePO4 battery has voltages exactly half of your 24V chart.
View attachment 801107

Many thanks, I had no idea the voltages would be that different for the different types.

Mark

 

[iandsm]

Hi All

Tomorrow will be my first experience of effectively wild camping, as we've only been hooked up on campsites since buying our van. There are 4 of us going away for a couple of nights. The fridge will be on gas so not a concern but we intend to try and watch a couple of football matches if possible (assuming a decent mobile signal) as well as using the lights, water pump, playing some music etc. The motorhome is brand new, as is the battery of course, so should we have enough power for a couple of days and is there anything I should look out for in terms of the battery getting too low? There is a solar panel on the roof too, although I've just read that they're basically useless according to dawsey

Actually they are not basically useless, mine produces more power than we can use in so non EHU places are our choice in the summer months. We charge phones and a laptop daily and of course use power to run the services. Of course in the winter when there is little sun there will be very little if any power generated but having said that I wouldn't be without solar.

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[dawsey]

Actually they are not basically useless, mine produces more power than we can use in so non EHU places are our choice in the summer months. We charge phones and a laptop daily and of course use power to run the services. Of course in the winter when there is little sun there will be very little if any power generated but having said that I wouldn't be without solar.

I’ve never said solar was ‘useless’. In an earlier thread I commented on the limitations of having them on the roof when the sun is blindingly hot on the continent and you have to always seek shade. The point was that in some cases a remote array would be more useful, particularly if you are a high energy user, and like to run the AC for a couple of hours at the end of the day etc.

None of that is an issue in UK where it never gets particularly warm. With a new van and more importantly new battery you should be fine. Some folks have posted the lead acid voltage/capacity chart so you can see what capacity you have left. The only point I would add is to check when the panel is not actively charging the battery, also with no load actively discharging the battery as the measured voltage may not accurately represent the remaining capacity.

 

[iandsm]

I’ve never said solar was ‘useless’. In an earlier thread I commented on the limitations of having them on the roof when the sun is blindingly hot on the continent and you have to always seek shade. The point was that in some cases a remote array would be more useful, particularly if you are a high energy user, and like to run the AC for a couple of hours at the end of the day etc.

None of that is an issue in UK where it never gets particularly warm. With a new van and more importantly new battery you should be fine. Some folks have posted the lead acid voltage/capacity chart so you can see what capacity you have left. The only point I would add is to check when the panel is not actively charging the battery, also with no load actively discharging the battery as the measured voltage may not accurately represent the remaining capacity.

I was replying to Birdy, it was he who used the phrase “ Basicall iseless

 

[Birdy67]

Sorry folks, I think my tongue in cheek comment has maybe been lost in the sands of time as I was referring to a thread that had just been started by dawsey that I suspect was also slightly tongue in cheek, but without context understandably that's been overlooked.

 

[meanders]

My Burstner dispaly reads 0.2 below the actual voltage of the battery. I know this as I check the battery level with a multimeter.

Surely that depends on the accuracy of the multimeter? I doubt the meter is 'calibrated'. It's also possible that the display is wired with long thin cables causing a voltage drop.

 

[VXman]

Surely that depends on the accuracy of the multimeter? I doubt the meter is 'calibrated'. It's also possible that the display is wired with long thin cables causing a voltage drop.

True - but it is an indication. I do not know what the solution to that is. Several different multi meters, a very expensive multi meter, a smart battery monitor ????

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[meanders]

I agree it's an indication. However people get hung up on a precise voltage whereas, an indication is often all that is required.

In reality the small difference you referred to is probably insignificant. It could actually be a lot smaller difference as one meter rounds down, and the other rounds up to the nearest 0.1V.

 

[autorouter]

True - but it is an indication. I do not know what the solution to that is. Several different multi meters, a very expensive multi meter, a smart battery monitor ????

I have often checked multimeters - cheap and expensive - against an expensive certified traceable calibrated bench meter. I have never found a multimeter that was significantly in error compared to the calibrated meter. I was initially surprised at how accurate they were, but now I just take it for granted. The bench voltmeter is accurate to a tenth of a millivolt, the cheap meters are accurate to a tenth of a volt or better.

 

[VXman]

I have often checked multimeters - cheap and expensive - against an expensive certified traceable calibrated bench meter. I have never found a multimeter that was significantly in error compared to the calibrated meter. I was initially surprised at how accurate they were, but now I just take it for granted. The bench voltmeter is accurate to a tenth of a millivolt, the cheap meters are accurate to a tenth of a volt or better.

Well, I'm no expert, but to be honest I would have thought measuring voltage is a fairly simple thing to do. Shouldn't really be a reason for too much variance.

 

[autorouter]

Well, I'm no expert, but to be honest I would have thought measuring voltage is a fairly simple thing to do. Shouldn't really be a reason for too much variance.

Yes I think you're right on this one. But looking at cheap thermometers for example, I found a large variation in accuracy. They typically 'measured' to the nearest tenth of a degree, some even to a hundredth of a degree. But the accuracy compared to a calibrated temperature was often poor, sometimes 0.5 degrees of error.

 

[dawsey]

As others have mentioned, dont worry too much about measurement accuracy. With practise you will see why.

It’s way more important to let the battery settle for some time before using voltage to determine remaining capacity. It might take a brand new battery that is fully charged and on charge via alternator at 14V as much as a couple of hours to settle to its 100% capacity voltage of 12.7V.

Similarly if your battery is only 50% charged and you run the engine the battery voltage will rise dramatically, and it will take some time to settle back to the 50% charge voltage of (from memory) roughly 12.1V.

As others have said, don’t get anxiety about it, worst case you will run out of power and need to run your engine for a few minutes to have lights to finish up what you are doing and have an early night

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