Inverter For SWMBO?

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dewent

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SWMBO is keen on us fitting an inverter so she can use a hair drier and heating tongs! Apparently they are essential for contented female cruising.

I am not an electrician so can anyone advise if the boat batteries with an inverter can successfully power such devices without being completely flattened?

Peace and harmony could be achieved aboard if I could successfully fit such a device.

Thanks...
 
dewent said:
SWMBO is keen on us fitting an inverter so she can use a hair drier and heating tongs! Apparently they are essential for contented female cruising.

I am not an electrician so can anyone advise if the boat batteries with an inverter can successfully power such devices without being completely flattened?

Peace and harmony could be achieved aboard if I could successfully fit such a device.

Thanks...
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Depends on:- size of battery bank, wattage of dryer and tongs, also how long will they be on and whether they will be on together.
At a guess I would say ypou will need a 2kilowatt inverter and a large battery bank.
Also a consideration is if the tongs are electronic tongs, (and most are) because a simple modified sine wave inverter will not run them, a pure sine wave inverter is required. (experience!)
 
dewent said:
SWMBO is keen on us fitting an inverter so she can use a hair drier and heating tongs! Apparently they are essential for contented female cruising.

I am not an electrician so can anyone advise if the boat batteries with an inverter can successfully power such devices without being completely flattened?

Peace and harmony could be achieved aboard if I could successfully fit such a device.

Thanks...
Click to expand...

Whats the power of the hair dryer she wants to use. whats the power of the tongs.
Add them together if both are used at the same time.

Hair dyers can be up to 2300watts but I suggest something less powerful for the boat.
No info on tongs

Look for an inverter that can supply that many watts contuously and a bit to spare.

Check the inverter spec for its maximum power consumption in amps

Multiply the amps by the time it will be in use in hours to get its consumption in Ah.

Do the same for all other equipment ie multiply the amps by hours use between battery recharging opportunities.

Add all the Ah figures together. Get a battery at least twice that AH in capacity.


Simpler solution: drop her off at the hairdressers/ health farm on the way to the boat... Go sailing ... pick her up on the way home :D
 
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I bought a couple 5 years ago from Maplins (600w and 1000w); they were cheap (~£50 for the 1000w). It runs a flat screen TV, all my electrical tools, laptop etc. I suggest you go for a 1500w inverter to be able to run a hairdryer for the SWMBO
 
We have a 2 Kw Mastervolt inverter it runs the hair drier, microwave, two slot toaster, kettle, two lap tops but of course not all at the same time, although the lap tops rarely go off except at night. Its all powered by 24 V and we have four big 12 V truck batteries.
 
mocruising said:
We have a 2 Kw Mastervolt inverter it runs the hair drier, microwave, two slot toaster, kettle, two lap tops but of course not all at the same time, although the lap tops rarely go off except at night. Its all powered by 24 V and we have four big 12 V truck batteries.
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I rest my case yer honour!
 
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If SWMBO wants to use a hairdryer and tongs, I can't imagine you being anchored in the middle of nowhere. More likely you'll be in the marina where SWMBO want to look her best. So why not install shore power running off the pontoons?? Some caravn units come complete with RCDs and everything and some - designd for trailer tents - don't even need permanent fixing.

Cheaper than an inverter and no risk of flat batteries.
 
Don't forget that you will need very thick wires from the battery to the inverter - 70mm2 to 95mm2, plus a big fuse, probably 400A or so.

How do I know? :) all for a hair dryer and a Hoover!
 
The current drawn at 230 volts by a 2000 watt hairdryer will be 8.7 amps (2000/230).

Assuming you have a 12 volt system:

To create 2000 watts from 12 volts you need to supply 166.7 amps (2000/12).

That means that it is going to take 166.7 amps out of your battery if your inverter is 100% efficient. I don't have hard data on efficiency, but I see at least 30% more power consumed by my laptop through an inverter than powered from DC. So you should probably reckon on 200 amps at least. it is well within the bounds of possibiity to get the equipment and cabling to deliver this much current, but you are talking hefty stuff. (It's more than the starter motor on my wee engine draws!) If you use the hairdryer for a quarter of an hour you'll take 50 amp hours out of the battery - scary stuff on my wee boat. If you have a hair dryer half as powerful but it takes twice as long you'll have drawn just as much out of your battery. Having a huge battery makes it more possible to cope with that load at the time, but if you take that much out you have to put it back in a again. If you have a an alternator which can charge the battery at 50 amps it'll take an hour to put your 50 amp hours back in - actually considerably longer because of (a) less than 100% efficiency (b) you can't maintain that high a charge rate as the battery approaches full charge.

So so it needs a hefty battery capacity, hefty cables, a hefty alternator, and lots of time charging the batteries.

All this is a non-starter on a wee boat like mine, but, as pointed out, I can run a hairdryer just fine directly off shore power if I'm in a marina.
 
We looked into this a while ago and the only answer we came up with from listening to others was to buy a generator. We got a honda 2.0.

I will say though, we have hardly used it so far. I can't be bothered to get it out just to dry my hair, so tend to just wash it and tie it up. :D
 
SWMBO has 12 volt hairdryer which she says is just about adequate.
What she does not know is that I use it in frosty conditions to start the donk by blowing hot air into the air intake. Engine starts instantly
Two for the price of one so to speak
 
Burnham Bob said:
If SWMBO wants to use a hairdryer and tongs, I can't imagine you being anchored in the middle of nowhere. More likely you'll be in the marina where SWMBO want to look her best. So why not install shore power running off the pontoons?? Some caravn units come complete with RCDs and everything and some - designd for trailer tents - don't even need permanent fixing.

Cheaper than an inverter and no risk of flat batteries.
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Sensible advice. Still, many hairdryers are over a 1000 W, and likely to trip the fuse in some marinas. In Holland, you seldom can run anything above 500 W.
Many moons ago, in my (hired) narrowboat days, I went to the nearby village, and on return I found find my wife having had a nice shower (heater on battery) and really nice hair, dried with the 12V dryer provided. And NO power left in the battery to start the engine.
 
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