Inverters (1 Viewer)

[Hotelman]

SWMBO wants to use her 1750w hair dryer when not on hook up.
An inverter seems the answer, and connected to the main battery, and then we can just run the engine for a few minutes when she's using it, we can also charge her e-bike battery when on the move.
We have been quoted £450 plus fitting for a 'an all singing and dancing 2kw' inverter. He said we could find a cheaper one on the 'net' which he would fit, but obviously wouldn't warranty it.

Help please, thanks.

 

[BreweryDave]

That's a lot of dosh just to dry hair

There are 12v dryers out there - probably crap but will get the job done?

Alternatively - buy her a nice towel and spend the balance on beer

 

[mitzimad]

if you have to run the van to dry her hair you might as well go for a ride with her head out the window

 

[DBK]

Someone can probably suggest alternative inverters but there are two main types, pure sine wave and not, so to speak, with a few shades in between. If you think you will want to run electronic equipment using the inverter then a sine wave inverter is what you need, but they are considerably more expensive. Worth checking what you are being quoted for. To just run a hair drier the square wave inverters will suffice but my only concern would be to run a 1750W hair drier a 2Kw inverter is going to be running more or less flat out. If for a little more money you can get a 2.5 or 3.0 Kw inverter things might be less fraught.

Just remember a 1750W hair drier is going to be taking around 150 Amps at least from your batteries and just running the engine won't keep up with that sort of drain so you will need to ensure the batteries are fully recharged afterwards, which if you are off grid could take several hours. A B2B charger could be your next big investment.

A pair of scissors and shorter hair is the answer - or stay on campsites with hair driers!

 

[scotjimland]

SWMBO wants to use her 1750w hair dryer when not on hook up.

what battery capacity do you have.. ? then do the sums..

the drier will draw 145 amps .. so if used for 15 mins it will use 37 ah .. that's about half the capacity in an 80ah battery .. ie .. it's flat , dead.. no use..

also, leisure batteries are designed to give relatively low currents for long periods... discharging rapidly and repeatedly will shorten it's life

and as DBK said.. "just running the engine won't keep up with that sort of drain "

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[pappajohn]

There are 12v dryers out there - probably crap but will get the job done?

No they won't.
There are many long threads on the subject of 12v driers.

 

[ASel]

All phones, computers, flat screen tvs and tablets run on DC via a transformer so they do not know if your inverter is pure sine or square wave.

 

[DBK]

All phones, computers, flat screen tvs and tablets run on DC via a transformer so they do not know if your inverter is pure sine or square wave.

But the transformer might. As in all things there will be exceptions but there are applications where you need pure sine wave. For laptops etc the simplest answer is a 12v adaptor, the sort you would use in a car to plug into the cigar lighter socket. No inverter required.

Unfortunately, my Olympus camera comes with a battery which can only be charged from a 240v supply, no one makes a 12v charger for it, so I am thinking about getting a small inverter. Just dragging my heels at the moment as the thought of spending money makes me feel feint.

 

[pappajohn]

It will if

and as DBK said.. "just running the engine won't keep up with that sort of drain "

It will if, as the op said, the inverter is connected to the main battery and not the auxiliary

 

[scotjimland]

It will if

It will if, as the op said, the inverter is connected to the main battery and not the auxiliary

missed the part about the main battery..

just run the engine for a few minutes when she's using it,

.. but 145 amps from the alternator.. I don't think so..

and risks not being able to start the engine..

I rather have a flat hab battery as engine battery

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[eddie]

Inverters when used sensibly are a uesful part of the motorhome. With a decent charging regime of B2B and solar, and a good sized battery bank there isn't much that you can't do with an inverter.

Just be aware that if you buy a cheap inverter from ebay that originates in China and it catches fire you'll have no back up or come back from the manufacturer, the same if it blows up your eBike lol

Electric toothbrushes, Medical equipment and good coffee machines are the main reason we come across for needing pure sine wave.

We've just been asked to tender for mobile laboratories for a local authority and the procurment officer didn't know the difference!

My wife would simply refuse to go way in our motorhome is the use of a hair dryer wasn't available! So we don't see it as an option lol

If your getting one installed, it is better to have it installed with a transfer switch, which is route your 13 amp sockets, for ease of use rather than having a "dedicated" inverter socket and having to trail extension leads around the motorhome

Eddie

 

[Deleted34567]

Honda i20 generator.
Even running genny at near 100% for prolonged periods is not recommended. Inverter will draw huge currents from battery at that wattage.

 

[joncris]

But the transformer might. As in all things there will be exceptions but there are applications where you need pure sine wave. For laptops etc the simplest answer is a 12v adaptor, the sort you would use in a car to plug into the cigar lighter socket. No inverter required.

Unfortunately, my Olympus camera comes with a battery which can only be charged from a 240v supply, no one makes a 12v charger for it, so I am thinking about getting a small inverter. Just dragging my heels at the moment as the thought of spending money makes me feel feint.

I have a USB cables for camera, video cam and iPhone which I often plug into (my when in use) laptop causing them to be charged

 

[Techno]

A 1750 watt drier you say?. These usually have 2 or even three heat settings. My wife never uses the full heat, have you asked yours?

 

[scotjimland]

With a decent charging regime of B2B and solar, and a good sized battery bank there isn't much that you can't do with an inverter.

.. as a general statement on inverters.. agreed.. I also had a similar set up in the RV with a large battery bank and Victron multi plus 1600 watt charger inverter

but does the OP want to spend a small fortune for his wife to dry her hair.. or for that matter have the available payload ?

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[funflair]

I would go for a pure sine inverter so you are future proof, at £450 I would suspect that this is, it needs to be wired as close to the batteries as possible with good thick cables, not sure which battery you are suggesting but personally I would be running from a couple of good quality leisure rather that the starter battery. My OH uses a dual heat/speed heat hair dryer on the lower setting so not 1750W and usually only for 5 minutes so takes next to nothing out of the batteries (1200W for 5 mins=9ah) and the solar can put it all back no problem (as long as there is a bit of sun) never need to run the engine and would not unless we were on our own. I would make sure that the inverter has a remote start/stop that can be mounted inside.

 

[funflair]

.. Quote clipped

but does the OP want to spend a small fortune for his wife to dry her hair.. ?

What price for a happy wife

 

[Techno]

And of course when these subjects arise (as often as gassing) I get to post my favourite

 

[scotjimland]

What price for a happy wife

she may be less happy when eddienobitz bill hits the carpet..

 

[funflair]

she may be less happy when eddienobitz bill hits the carpet..

The one thing she doesn't mind and is quite good at is "spending money"

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[Gizmouk]

I can only echo what others have said regards only using a pure sine wave inverter. Avoid using the cheap Chinese rubbish on eBay.

Using the engine / cab battery is a bit of a non-starter. Engine batteries are designed to provide high instantaneous power for very short duration. Leisure batteries are designed to give lower power over a much longer period. Running the engine wont be much help, as your alternator wont give out 145A.

Cable calc:
Based on assumptions -
1750W load
3m cable run
12v battery
2% accepted volt drop
Cable Size = 95mm2

If you keep the cable run (between battery and inverter) to less than 1m, then you can get away with 25mm2

Important to note that at 1750W, that inverter will be kicking out a lot of heat. Due consideration will need to be given to installation and airflow.

Personally, I'd recommend .... a towel

 

[eddie]

she may be less happy when eddienobitz bill hits the carpet..

We're not doing it lol Don't blame us! We only under take work for people that want the right equipment fitted for the job in hand. You know, where the use of the motorhome with the minimum of compromise is more important than how much you "could" of saved, buying a third hand one and fitting it yourself

 

[Techno]

Avoid using the cheap Chinese rubbish on eBay.

Wot like Sterling?

 

[MitchandJenny]

How about :- Closing all the vent outlets on your blown air heating EXCEPT one, into which you then connect a tapering (hoover sort) of hose.. Then, just turn up your heating and the blower and "hey ho" HAIR we go !!!!
For pennies... Mitch.....

 

[Gizmouk]

Wot like Sterling?

Not exactly the cheap end of the market, as alluded to

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[Techno]

The one on the left is a 2000watt continuous pure sine UPS inverter 4 stage intelligent charger (cost me £213 from ebay germany) Chinese.
The one on the right is a 1600 watt Sterling pure sine inverter only £322 also Chinese.
I know which I prefer

 

[eddie]

How about :- Closing all the vent outlets on your blown air heating EXCEPT one, into which you then connect a tapering (hoover sort) of hose.. Then, just turn up your heating and the blower and "hey ho" HAIR we go !!!!
For pennies... Mitch.....

LOL That would work Mitch, until my wife replaced the Stella on the Conveyor belt with a home brew kit and made noises about Good for the Goose etc lol

 

[Techno]

I used 70mm BTW, it's not expensive DIY

 

[Chockswahay]

How about :- Closing all the vent outlets on your blown air heating EXCEPT one, into which you then connect a tapering (hoover sort) of hose.. Then, just turn up your heating and the blower and "hey ho" HAIR we go !!!!
For pennies... Mitch.....

That is virtually exactly what Caravan makers use to fit about 30 years ago........... it worked too

 

[Chockswahay]

@Techno100 I gotta say all the photo's you have posted recently are impressive stuff indeed ! Are you a professional or simply someone who believes in 'doing it right' ?

I have followed a few of your threads and the attention to detail is excellent. Thank you for posting them

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