Inverter

[Big Ted]

What is the best inverter for my autotrail apache 700

 

[John H.]

You need to tell us why you need one.

What are you going to do with it?

Charge mobile phones?
boil a kettle?
run air conditioning?

 

[Big Ted]

Just for charging phones and my Mrs will use a hair dryer and straighteners

 

[John H.]

The hair dryer will be the issue. Look up what power it uses.

 

[Big Ted]

1000watts on low 1500watts on high power, But can always buy a low wattage hair dryer.

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[Lenny HB]

What size is your battery bank?

If you fitted a 2000 watt inverter but only took a max of 1500 watts out of it you would need 400 ah of batteries, you can get away with less but it will shorten the life of the batteries.

 

[funflair]

You really need a 2kw pure sine wave, do you have the batteries and solar to run it for any length of time?

 

[Big Ted]

Yes have twin batteries and solar panel fitted, thanks will have a look at that

 

[Richard n Ann]

Look at the Babyliss Big Hair. 750w. Ann likes it

 

[VXman]

What size is your battery bank?

If you fitted a 2000 watt inverter but only took a max of 1500 watts out of it you would need 400 ah of batteries, you can get away with less but it will shorten the life of the batteries.

Surely how much wear on the battery would depend on the length of time the hairdryer was on for? Or is it the power draw that is the issue...not time? Don't really understand this stuff but trying to is we were also thinking of an inverter too....just for occasional use along similar lines.

We have 200Ah batteries - so would that be a problems for 1500w of usage?

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[Raul]

Start with the power that is needed. For example 1000w divide by 12v operating system. That’s 83a needed to come out of the battery. A lead of any kind can discharge a max C/5 current. The C is your total battery capacity divided by 5. In our case we have 83a needed times 5 = 415ah battery bank to sustain a 1000w load. Any more is abuse on batteries. When you have a large load and small battery bank, you help it with direct solar production and engine alternator. If you want large power draw lithium is your friend.

 

[autorouter]

Just for charging phones and my Mrs will use a hair dryer and straighteners

Inverters are best used for high power in short bursts, and only turned on when they are actually in use. Most have a no-load drain that will flatten your batteries if left on all the time.

Phones are charged usually from USB, which is about 5V, so a 12V to USB adapter is the best way for them. There are different grades of USB adapter - the easily available ones are often very low power (1A or 2.1A). Modern phones need higher power, such as QuickCharge3 (QC3). Or USB-C with PD (Power Delivery). Fit a couple of cigarette-lighter type sockets, and buy adapters. That way you can easily change them when you get a new phone.

 

[eddie]

My wife uses a Dyson hair dryer daily and would refuse to go in the camper unless that is available

Most of the year our inverter is rarely off as we use it for so many things

 

[cmcardle75]

Just for charging phones and my Mrs will use a hair dryer and straighteners

I wouldn't use an inverter to charge phones. It's much better to use a 12V charger than have a massive 2000W inverter (needed for the hairdryer) for a tiny 10W load.

Some people do have "full time" inverters, though, where they basically run it 24 hours a day (especially if they want to run a cheap 230V compressor fridge). This can be a bit wasteful of energy, but that isn't a problem if you have a large solar array and lots of lithium batteries.

 

[Lenny HB]

As Raul says the limiting factor is the C5 discharge rate if you want your batteries to last, so 20 amps from a 100 ah battery.
It's even worse than he states as you need to allow for inverter efficiency so so 1000 watt inverter is going to draw around 93 amps or more.

If only using the inverter occasionally you can get away with drawing more than the C5 rate around 30 amps is generally OK, without too much effect on battery life. But that means you still need at least 300ah of batteries to run a 1000 watt inverter or 600 ah for a 2000 watt one.

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[Nixdorfer]

When we tested OH's GHD straighteners we found they only worked on a Pure Sine wave. Other makes might be ok but if not going for a Sine wave check before you buy.

 

[royw]

when you say you have 200ah batteries what type and is that total, each battery tpe hasa discharge threshold, so you may not have as musch usefull power as you think.

 

[VXman]

when you say you have 200ah batteries what type and is that total, each battery tpe hasa discharge threshold, so you may not have as musch usefull power as you think.

when you say you have 200ah batteries what type and is that total, each battery tpe hasa discharge threshold, so you may not have as musch usefull power as you think.

I assume you were referring to me as I mentioned 200ah. I have 2 95ah batteries linked together to be precise. They are AGM's

 

[Lenny HB]

We have 200Ah batteries - so would that be a problems for 1500w of usage?

Yes for 1500 watts you need 600 ah or at a push you could get away with 400 ah.

 

[BillyKontiki]

We have 220 ah of lithium and a 3000/6000 w Giandel modified sign wave inverter, and have no problem at all with 1200 w hair drier , tongues 1200 w kettle, coffee machine , toaster 800 micro. charging Mac and phone’s etc.
And all my wife’s stuff too.
Best of luck in choosing there are lot’s out there.

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[Lenny HB]

We have 220 ah of lithium and a 3000/6000 w Giandel modified sign wave inverter, and have no problem at all with 1200 w hair drier , tongues 1200 w kettle, coffee machine , toaster 800 micro. charging Mac and phone’s etc.
And all my wife’s stuff too.
Best of luck in choosing there are lot’s out there.

Different ball game with Lithium a lot of them you can draw current at the C1 rate.

 

[gerry mcg]

glad I only fitted a 500W PSW victron inverter with my 190Ah AMG battery bank then.
I wasn't aware of the C/5 rule of thumb - but im matched with the 500W inverter

 

[Lenny HB]

glad I only fitted a 500W PSW viltron inverter with my 190Ah AMG battery bank then.
I wasn't aware of the C/5 rule of thumb - but im matched with the 500W inverter

Most people aren't & a lot get away with it, I certainly wouldn't want to risk it with AGM's.

 

[royw]

yu

I assume you were referring to me as I mentioned 200ah. I have 2 95ah batteries linked together to be precise. They are AGM's

yup 200 or 200 useable is down to the type as I am sure your aware, i am exactly the same for the time being.

 

[pappajohn]

.

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[Clive Mott]

Most has been said. Take heating out of the requirement, that's hair dryers, kettles and microwave oven out the list then it's easy. But just a 600 watt Daewoo microwave or a TESCO Toaster and you need 1800 Watts of pure Sine Wave capability. That's us with a 150AH Lithium battery and all spare landscape covered with solar panels.

 

[PJGWiltshire]

Start with the power that is needed. For example 1000w divide by 12v operating system. That’s 83a needed to come out of the battery. A lead of any kind can discharge a max C/5 current. The C is your total battery capacity divided by 5. In our case we have 83a needed times 5 = 415ah battery bank to sustain a 1000w load. Any more is abuse on batteries. When you have a large load and small battery bank, you help it with direct solar production and engine alternator. If you want large power draw lithium is your friend.

Why is it every time I see a posting headed Inverter/hairdryer i get so confused.

Please can clarification be given to help me on this.
I know nothing about 12v power but can complete tasks when guided.
I have many upgrades on the van. Stirling B2B, 175w solar a 2000w inverter. Victron smart shunt and I have a pair of brand new 95AH gel batteries.

I use the inverter in the main to run a 750w little coffee machine, charge Mac laptop (85w) and using a 1400 w Dyson hairdryer. Now on the inverter I have 200A fuse and 25mm cables. The hair dryer when operated is for around 10 minutes off and on in the morning only when the shunt shows the batteries at 100%. From the comments around C/5 ( a first for me on this info) is it said that I simply do not have enough battery bank power.
Any info would be helpful

 

[autorouter]

Why is it every time I see a posting headed Inverter/hairdryer i get so confused.

Please can clarification be given to help me on this.

A lead-acid battery has a low internal resistance, and can supply massive currents. A 100Ah 'dual-purpose' starter/leisure battery can probably supply 700A to a starter motor for a few seconds, up to a minute or so. Gel and some AGMs are less tolerant. They can probably still supply this current, but it will cause internal heating, gassification and possible damage, especially long-term.

However running an inverter is a different ballgame, in that the high power can be sustained for several minutes or even hours. Inverters are used in all kinds of situations, including off-grid houses, where the electrical demand is the same as any other house.

For batteries powering inverters that supply such houses, it has been found that for best long-term battery life, the amps should be restricted to C/5. In fact some say C/10 is even better.

These batteries are in use 24/7, and usually weight and size are not big considerations.

For a motorhome this rule would apply if you are using a high power continuous load, like aircon. If you are charging batteries from the engine alternator, or a genny, so that the aircon can run overnight for example.

If you are using short power bursts, like a microwave or hair dryer, this rule can be relaxed a bit, because the heat doesn't get chance to build up so much.

Using a high-power inverter is one of those situations where the expensive gel batteries are in fact not as tolerant as cheaper 'dual-purpose' flooded lead-acid batteries.

 

[gerry mcg]

Why is it every time I see a posting headed Inverter/hairdryer i get so confused.

Please can clarification be given to help me on this.
I know nothing about 12v power but can complete tasks when guided.
I have many upgrades on the van. Stirling B2B, 175w solar a 2000w inverter. Victron smart shunt and I have a pair of brand new 95AH gel batteries.

I use the inverter in the main to run a 750w little coffee machine, charge Mac laptop (85w) and using a 1400 w Dyson hairdryer. Now on the inverter I have 200A fuse and 25mm cables. The hair dryer when operated is for around 10 minutes off and on in the morning only when the shunt shows the batteries at 100%. From the comments around C/5 ( a first for me on this info) is it said that I simply do not have enough battery bank power.
Any info would be helpful

I guess the rate of discharge is the issue as well as the depth of discharge.
A "big" inverter has the capability of drawing down the battery much faster than a small inverter, and as a consequence, damaging the battery longevity.
E.g a 500w inverter would draw 42A (500w/12v) assuming 100%, efficiency (make that nearer 45A if you assume 90% efficiency) that is thereab the C/5 rule of thumb for discharge rates.
Even a 500W inverter running at full power would draw a 200Ah battery bank to 50% SOC in 2 hrs.

A 2000w inverter would draw 167A (@100% efficiency / 185A at 90% efficiency) at full- power and drain a 200Ah battery bank to 50% SOC in 30 min.

It is this rate of discharge that is the issue (for lead acid / AGM / gel batteries) from what I can gather. Lithium is not a problem

I guess you are not using the full 2000w of the inverter capability for extended periods of time but I guess any rapid current drain is bad for the battery chemistry & life

 

[Al n Val]

We have 220 ah of lithium and a 3000/6000 w Giandel modified sign wave inverter, and have no problem at all with 1200 w hair drier , tongues 1200 w kettle, coffee machine , toaster 800 micro. charging Mac and phone’s etc.
And all my wife’s stuff too.
Best of luck in choosing there are lot’s out there.

we have the same inverter but 200ah of pure lead Carbon batteries, may i ask if you have a fuse/trip between the inverter and batteries and if so what size is it.

Using our new 1100w Kampa kettle it trips my 150a trip switch before boiling so i'm asking if i need to go higher with the trip current rating

Any help from anyone would be really appreciated

thanks Al