12v to 240v Inverter Recommendations

[Medved_77]

Anyone able to recommend an Inverter that will work well from the 12v in the model 3?

Main use will be for charging a laptop at ~100w

I've looked on amazon and prices seem to vary from £20-£200 so not really sure where the sweet spot is.

 

[Mr H]

Always go larger so there is a little headroom

this would be a good option
Ring Automotive PowerSource Inverter 300w RINVU300 | Halfords UK

 

[Medved_77]

Always go larger so there is a little headroom

this would be a good option
Ring Automotive PowerSource Inverter 300w RINVU300 | Halfords UK

Thanks for this. Is Ring Automotive a reliable brand (or does it matter)?

Will check the dimensions as it would be nice if the invertor could stay within the well under the armrest providing overheating is not an issue.

 

[Neilman]

If *all* you want to do is to charge a laptop then you could go for a charger module that plugs into the cigar socket and has the appropriate plug for the ~19v DC input socket of the laptop. Saves using the laptop's AC charger and various mains plugs

 

[Medved_77]

If *all* you want to do is to charge a laptop then you could go for a charger module that plugs into the cigar socket and has the appropriate plug for the ~19v DC input socket of the laptop. Saves using the laptop's AC charger and various mains plugs

Thanks, had thought of that approach but haven't been able to find one that works with surface connect.

 

[Mr H]

Thanks for this. Is Ring Automotive a reliable brand (or does it matter)?

Will check the dimensions as it would be nice if the invertor could stay within the well under the armrest providing overheating is not an issue.

I have a couple of Ring products which have proven to be reliable and well made

 

[NewbieT]

I’ll throw in a couple of suggestions. I have a surface so feel you pain.

https://www.amazon.co.uk/dp/B07QV1PYK9

https://www.amazon.co.uk/dp/B07MPMM97V/

 

[Medved_77]

I’ll throw in a couple of suggestions. I have a surface so feel you pain.
https://www.amazon.co.uk/dp/B07QV1PYK9
https://www.amazon.co.uk/dp/B07QV1PYK9

https://www.amazon.co.uk/dp/B07MPMM97V/

Thanks for the links. I've got the 15" surface book 2 which is pretty power hungry especially when running some of the work apps. Not sure if 36w would cut it, the wall charger I think is 102w.

 

[NewbieT]

You can sometimes charge more slowly at a lower wattage and it’ll still work.

Microsoft’s official version: but it isn’t in the UK Microsoft site. You can find the same here on Google. 2.5A so not 102w.

Buy Griffin Surface Link Vehicle Charger - Microsoft Store

 

[LukeUK]

Assuming you're planning on plugging in to the 'cigar lighter' socket, you need to consider the total power draw.

12 A x 12 V = 144 W, so the 300 W inverter above could easily overload the supply, if you load it up.

Even if you don't load it up, you should consider the efficiency of the inverter. These quasi-sine wave inverters are not particularly efficient, 90% is good, 75-80% isn't uncommon.

This means that to draw 100 W at 230 V, you could be drawing between 111 and 133 W at 12 V.

There's also these warnings;

 

[Medved_77]

Assuming you're planning on plugging in to the 'cigar lighter' socket, you need to consider the total power draw.

View attachment 562537

12 A x 12 V = 144 W, so the 300 W inverter above could easily overload the supply, if you load it up.

Even if you don't load it up, you should consider the efficiency of the inverter. These quasi-sine wave inverters are not particularly efficient, 90% is good, 75-80% isn't uncommon.

This means that to draw 100 W at 230 V, you could be drawing between 111 and 133 W at 12 V.

There's also these warnings;

View attachment 562540

Thanks for that. Ordered a 300w invertor an hour ago and have just cancelled it.

Guess this project needs a rethink.

 

[LukeUK]

Sorry to be the bearer of bad news.

300 W at 12 V is 25 A. That's a fair draw. Most inverters that size will require wiring to the battery, or will at least be getting the cigar lighter plug reasonably warm.

The 'cigar lighter' socket, as far as power connectors go, is really pretty rubbish, but it's a hang-over from a design that has evolved to be something now that it never was intended to be in the first place.

An efficient 100 W inverter would be do-able, but even then it's close.

This is a UK-based company (don't get me wrong, the unit will almost certainly be made overseas), 100 W, but it's fused at 15A - so just within the car's 16 A peak.

https://docs.rs-online.com/ed16/0900766b8070b666.pdf

230V Pro Power Q Quasi Sine Inverters 12 & 24V 100-5000W

I don't know what the car's internal battery charger is rated at. My understanding is that the 12 V battery is charged by the main battery bank. This charger will have its own current rating. Assuming the cabin heater/air-con fans run at 12 V, this charger must have a reasonable current rating, as fans can be pretty current-hungry. You'd hope that Tesla have factored in the 12 A (16 A) potential draw above, plus the car's own loads.

 

[Neilman]

Some of the higher power 12v to mains inverters (250W+) additionally come with a cable to allow direct connection to the 12v battery.
In an ICE car there's usually plenty of power to spare from the alternator (as long as you have the engine running of course).
Since the Tesla has a different mechanism for 12v charging it would probably unsafe to use direct battery connection for this.
If you can find an inverter that goes from 12v directly to the DC input voltage of the laptop that would probably be the most efficient since you wouldn't be converting 12v to 240vAC then converting back down from 240vAC to laptop voltage.
If it is of lower power than the laptop would ordinarily expect it will still charge especially if the laptop is not being used.
Even if the laptop is being used some charging current would offset the normal laptop battery drain.

 

[tsh2]

You can take 12V from under the back seats at a fairly high current (100 or 200A), but then need to be extremely careful about inrush current (and tripping to over-current protection), and short circuits which might not trip the protection circuit but still cause a fire. Don't use the 12V battery in the frunk - this almost certainly will cause problems since the load on that battery is carefully limited.