Advice for using laptop in motorhome

yorkieman

yorkieman

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I have some side projects I need to work on. I have one of those 12v to a conventional plug adapters to plus my laptop into. It works fine for half an hour to an hour, but it then starts bleeping every few seconds. I figure that is saying the power must be too low or something.

Thing is, I have two new leisure batteries so I was hoping to have been able to work for at least a whole day.

Does anybody know of any adapters, chargers, or battery packs, or anything else, I could get to be able to work more effectively.

Thanks for the tips and advice :)
 
Do have a usb charger? You could fit an inverter and use the 230v charger
 
I think he has an inverter already "12v to conventional plug adapter" when it starts to beep it would be worth checking on the battery voltage with a multimeter or whatever gauge you have in the van, what batteries have you got? and do you have solar?
 
there are plenty of 12v laptop chargers rather than use an inverter to create 230v ac from 12v, then a laptop charger to create 19v dc. loads of losses in that system
 
Many USB chargers are only about 1amp so may be worth checking what your adapter pumps out

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You need to look for a car charger adaptor for your laptop to make the best use of your batteries.

However, it sounds like your batteries are running down quite quickly. This suggests they may have reached the end of their life although if it is a high end laptop they use a lot of power.

Solar, if you have it won't do much at this time of the year if you are in northern Europe.
 
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where and how you connect an inverter also has a massive difference. a 12v socket supplied by a long thin wire will have a large voltage drop, so will trigger the inverters low voltage warning
 
TheBig1 said:
there are plenty of 12v laptop chargers rather than use an inverter to create 230v ac from 12v, then a laptop charger to create 19v dc. loads of losses in that system
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Really? What would I search for on Amazon, or do you suggest somewhere better? Thanks!
 
TheBig1 said:
where and how you connect an inverter also has a massive difference. a 12v socket supplied by a long thin wire will have a large voltage drop, so will trigger the inverters low voltage warning
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OMG! I know so little. It is awesome to have access to people with far bigger brains on this stuff.

The lead from the 12v mini cigar lighter thing, is just a typical power type width I'd say. Definitely nothing thick for sure.
 
DBK said:
You need to look for a car charger adaptor for your laptop to make the best use of your batteries.

However, it sounds like your batteries are running down quite quickly. This suggests they may have reached the end of their life although if it is a high end laptop they use a lot of power.

Solar, if you have it won't do much at this time of the year if you are in northern Europe.
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We only got the batteries a couple of months back so they should be fine. I do know when the bleeping starts the onboard console shows them being around 11 volts (ish), but it is an analog type console so isn't exactly accurate I don't think.

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First thing is to look at your laptop mains charger, to see what power it is. For example, if the output is 19V 4A, the power is 19 x 4 = 76 watts. Then look for a 12V laptop adaptor with the same or larger power. They usually come with a selection of laptop power plugs, unless you get one specifically for your model.

The voltage needs to be the same (usually 19V), and the amps can be the same or higher. The laptop will only draw the amps it needs.

Devices that use 120 watts or less are best powered by adaptors plugged into the 12V sockets.
 
funflair said:
I think he has an inverter already "12v to conventional plug adapter" when it starts to beep it would be worth checking on the battery voltage with a multimeter or whatever gauge you have in the van, what batteries have you got? and do you have solar?
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The console is showing around 11 volts (ish) when the bleeping starts. I would have a clue what to do with a multimeter even if I had one. I used to work at Tandy's when I was 18 (a long time ago) so should have acquired that knowledge then, but never did.

The motorhome is outside in the rain at the minute so can't remember, but they're heavy duty ones from Halford's and we got them a couple of months back.

As for solar. We should have got that years ago, but didn't. It is on my list to get that sorted this year.
 
yorkieman said:
We only got the batteries a couple of months back so they should be fine. I do know when the bleeping starts the onboard console shows them being around 11 volts (ish), but it is an analog type console so isn't exactly accurate I don't think.
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Anywhere near 11 volts and they are flat, what batteries are they? and how do you recharge while you are away?
 
The device that changes the 12V DC from the battery to 240V AC mains socket is called an inverter. What power is your inverter? You can get inverters from 100 watts to 3000 watts. High power inverters can cause the sort of problem you describe.
 
yorkieman said:
We only got the batteries a couple of months back so they should be fine. I do know when the bleeping starts the onboard console shows them being around 11 volts (ish), but it is an analog type console so isn't exactly accurate I don't think.
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Anything less than about 12 volts indicates a 50% degree of discharge which is as low as lead acid batteries should be taken. If you have consistently taken them down to 11 volts they may be permanently damaged even though they are new.

It is worth getting a cheap multi-meter from somewhere like Screwfix to double check the voltage.

You need to establish if the batteries are getting properly recharged, work out the load and then you should have an idea where the problem is.

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DBK said:
Anything less than about 12 volts indicates a 50% degree of discharge which is as low as lead acid batteries should be taken. If you have consistently taken them down to 11 volts they may be permanently damaged even though they are new.

It is worth getting a cheap multi-meter from somewhere like Screwfix to double check the voltage.

You need to establish if the batteries are getting properly recharged, work out the load and then you should have an idea where the problem is.
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If I order a cheap multimeter online are they pretty straight forward to use? Would I just check them when they're fully charged, and would that give me a better reading than the habitation console?
 
yorkieman said:
Really? What would I search for on Amazon, or do you suggest somewhere better? Thanks!
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I have a few, most bought on ebay. a sub £10 generic one that works but gets hot. heat is wasted energy so not efficient. A sub £20 universal "brick" type that worked for a month then died without warning. A kensington traveller universal, works really well. A larger £40+ maplin universal that works well too

either of the last 2 I would recommend, because they have proved reliable used on multiple laptops, but the kensington has more adapters
 
autorouter said:
YouTube is your friend. Any cheap multimeter will measure volts and continuity. It's a basic toolkit item in a motorhome.
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Oh my :-( I am just watching some Youtube vids as you suggest. I am clearly doing this all wrong as I know NOTHING about this stuff. And it seems like I should as we seem to go through batteries every two or three years. Looks like I will have to ditch the idea of my getting a portable coffee grinder for my birthday and get a multimeter instead :-(

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TheBig1 said:
I have a few, most bought on ebay. a sub £10 generic one that works but gets hot. heat is wasted energy so not efficient. A sub £20 universal "brick" type that worked for a month then died without warning. A kensington traveller universal, works really well. A larger £40+ maplin universal that works well too

either of the last 2 I would recommend, because they have proved reliable used on multiple laptops, but the kensington has more adapters
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It is a Maplin one that I have. I think it is 150 watts (or whatever measurement they use). It is outside at the moment so I can't look, but it is defo a steel/aluminium type casing with Maplins on it.
 
yorkieman said:
If I order a cheap multimeter online are they pretty straight forward to use? Would I just check them when they're fully charged, and would that give me a better reading than the habitation console?
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They are very easy to use. :)

But I think there are two issues. The first is to establish if the analogue meter is accurate. This is also easy to do, just check the voltages and see if they look similar.

The other issue is the much more complex subject of charging voltage to determine if the batteries are being properly charged.

I suggest take it in stages and check the accuracy of your on board volt meter first.
 
Most laptops are 19v, so all you need is a, small inverter, Halford do one that plugs into the 12v plugs and converts to 240v with low Watts, around 150w, which all you have to do is then plug in your laptop charger and away you go. You just need to make sure that your hab batteries are topped up, solar or ehu.
 
There's a lot of possible bad connections and faults between the battery terminals and the display console. It's OK for normal use, but not for fault-finding.

Set the meter to 20V DC range. Plug the black probe lead into the COM (= common) socket. Black is negative. Plug the red probe lead into the 'V-Ohms-mA' socket. Red is positive.

Turn on the meter. Push the black probe onto the negative battery terminal. Push firmly to cut through any crud/oxidation down to the metal. Push the red probe onto the battery positive terminal. The reading should be between about 10 to 15 volts. If you happen to reverse the connections, nothing bad happens, just a minus sign shows on the display.
 
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First question, exactly what batteries have you bought (make/type/power etc), they may be heavy duty but heavy duty for what? If they are not proper leisure batteries that might be the issue as a fully charged battery should run a laptop for a long while assuming the battery hasn't already been heavily discharged.

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yorkieman said:
It is a Maplin one that I have. I think it is 150 watts (or whatever measurement they use). It is outside at the moment so I can't look, but it is defo a steel/aluminium type casing with Maplins on it.
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Q1. Where do you plug your Maplin inverter into? The dashboard 12v socket, or one in the van connected to the two leisure batteries. If the dashboard, you are probably connecting to the engine battery. If the socket is in the habitation area, you are probably connecting to the leisure batteries. Which are flat as stated by others if only showing 11v. So.
Q2. How do you charge the two leisure batteries?
 
What sort of beeping noise does it make, this may give an idea of what the problem is:

Screenshot_20201005-081120.png
 
Some rough calculations: Your two batteries are likely to be at least 80 Ah (amp-hours) each. If they are fully charged, and you use them until they are discharged down to no lower than 50%, as usually recommended, then you have a usable 80Ah of battery capacity.

Your laptop charger is probably about 60watts. That's 60/12 = 5 amps from a 12 volt battery.

Your 80Ah should last for 80/5 = 16 hours.

If you're getting an alarm after 30 minutes, there's something very wrong somewhere. The 150 watt inverter will not be overloaded by the laptop charger, so it's not that.

You need to take some voltage readings in normal use, and when the alarm is sounding. Then you'll be able to see if it's the battery or the wiring that's a problem.
 
yorkieman said:
Really? What would I search for on Amazon, or do you suggest somewhere better? Thanks!
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It depends on your laptop. The latest laptops are USB-C with PD (=Power Delivery). Apple laptops have their own special chargers, I don't know much about them.

Most other laptops can use a 'Car Laptop Adapter', which converts 12V DC from the battery to whatever DC the laptop uses, usually 19V. This is usually more efficient powerwise than a 240V inverter and a 240V laptop charger.
This one, for example, is for up to 90 watts, and has 8 interchangeable tips that will fit most laptop power inlets. But not absolutely all of them, so worth checking if your laptop is at all unusual.
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