Power advice re invertors (1 Viewer)

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RVFUN

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We have solar so 12 volt can anyone recommend an invertor for charging electric bikes whilst driving running engine and perhaps using hair drier straighteners. We have 12 volt all the time just not 240 volt and don’t always have hook up. I thought about Honda suitcase generator but this looks more to carry so trying easiest and cheapest method first. TIA.
 

Doctor Dave

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It will largely depend on the amount of batteries you have. For charging the bikes you will almost certainly need a pure sine wave inverter. Not sure about the hairdryer straighteners but anything that produces heat will take a lot of power.

Someone will be along with more facts and figures no doubt.

Dave
 
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DBK

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Start with the wattage of the loads you want the inverter to supply. You might be able to go smaller but a 1500W pure sine wave inverter should be enough and will meet any future needs like a small coffee machine.

Something like this will be the best way to measure actual power requirements.
 
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RVFUN

RVFUN

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We have a 2017 MH with solar but need an additional power source for charging electric bikes and hair drier straighteners. I understand whispers charge on 12 volt but all others are standard 240 voltage. Can anyone suggest something other than going the silent generator route as this will be heavier and more to carry. I would also like to run aircon but realise that is a lot more power so we have transcools we can use on 12 volt as need this for a sick dog but again any better solutions seperately for aircon welcome.Trying to research so we it the most appropriate source.TIA.
 
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funflair

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Start with what your power demands will be and then how much battery capacity you have in the van and how much solar you have or how often you drive.

That at least will tell you if it is even feasible.

Martin

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Get a 'babyliss big hair' hair dryer only 700w, Ann loves them. They will run great from a 1000w pure sine wave inverter. You ideally need at least 2 batteries though (y)
 
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You need to work out your power requirements. For this you need to know how to convert from power units used by motorhomers (Ah), to power units used by everyone else (kWh).

Because motorhomes have 12 volt circuits, power is measured in amp-hours, assuming the voltage is 12 volts. For example, a typical leisure battery will have a power capacity of 100 amp-hours. Because it's a 12 volt battery, that's 12 x 100 = 1200 watt-hours. Amp-hours x voltage = watt-hours. To convert watt-hours to kilowatt-hours, just divide by 1000. So 1200 watt-hours = 1.2 kilowatt-hours.

Hair dryer wattages vary, but typically are about 1000 watts. To run it for 20 minutes (1/3 of an hour) will use 1000 x 1/3 = 333 watt-hours.

To put that in perspective, a typical 100 watt solar panel will produce about 48 amp-hours on a good long sunny day. That's 48 x 12 = 576 watt-hours. So it should put back whatever a hair-dryer takes out in an average day.

I think a typical bike battery is about 300 watt-hours, which is 25 amp-hours in MH units.

The other consideration is the peak current (amps). Starter batteries are designed to supply a massive current for a few seconds to a starter motor, but leisure batteries are designed for for a more sedate life. It's best to keep the amps from a 100Ah battery to 30 amps or less.

A 1000 watt load on an inverter will take about 85 amps from the 12 volt supply. So you'd need three 100Ah batteries in parallel to keep the amps below 30 amps for each battery. In practice two batteries will be OK, if it's only for 20 minutes or so. But a single 100Ah battery will struggle, and its life may be shortened.
 
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thebriars

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We have a 2017 MH with solar but need an additional power source for charging electric bikes and hair drier straighteners. I understand whispers charge on 12 volt but all others are standard 240 voltage. Can anyone suggest something other than going the silent generator route as this will be heavier and more to carry. I would also like to run aircon but realise that is a lot more power so we have transcools we can use on 12 volt as need this for a sick dog but again any better solutions seperately for aircon welcome.Trying to research so we it the most appropriate source.TIA.

We have 2 Wisper electric bikes, and they can only be charged using their 240v chargers. It is very dangerous to consider charging any lithium battery pack using anything other that the designated charger.
 
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Jan 19, 2014
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I would say 3 minutes is enough to dry a head of hair though if it's been rubbed with a towel first. Maybe 5 max :emo:
 
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denisejoe

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Depends how thick your hair is! Definitely takes longer when it's thick. Mine used to take nearly an hour when it was long with a hair dryer but I preferred to dry it naturally and it took nearly 3 hours! Much better now as I've had it cut short so don't bother with hair dryer at all!
 
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Lanerboy

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We have 2 electric haibikes and can charge both at the same time plugging both 240v chargers into the MH sockets and they charge fine without the engine running.

We have the factory fitted inverter that came with our carthago but I can't tell you what power it is as I can't find any markings on the inverter at all maybe another member can enlighten me on the inverter power fitted at the factory to give you an idea of what is required
 
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Apr 17, 2016
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Lanerboy I think it will be an 1800W inverter as that seems to be the standard across most of the Carthago range.How many batteries have you fitted? 2 or 3?
 
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Lanerboy

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Lanerboy I think it will be an 1800W inverter as that seems to be the standard across most of the Carthago range.How many batteries have you fitted? 2 or 3?

I just have the 2 standard batteries but been away for 2 weeks with no hook up and it's been fine

Only use inverter to charge ebikes the wife's hair dryer and straighteners and 1000w kettle

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The Dometic 1800W inverter used by Carthago is a pure sine wave type and I use mine to power the microwave, a 1000W kettle and a 1250W coffee machine on a regular basis. My battery power comprises two 110Ah gel batteries which gives me the same useable amp hours as three 110AH lead acid batteries due to them being able to be discharged down to 10% capacity, as opposed to 50% for lead acid.
 
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funflair

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The Dometic 1800W inverter used by Carthago is a pure sine wave type and I use mine to power the microwave, a 1000W kettle and a 1250W coffee machine on a regular basis. My battery power comprises two 110Ah gel batteries which gives me the same useable amp hours as three 110AH lead acid batteries due to them being able to be discharged down to 10% capacity, as opposed to 50% for lead acid.
I think most Gel are recommended not below 20% but the lower you go the less life you get.

Martin
 
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thebriars

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The Dometic 1800W inverter used by Carthago is a pure sine wave type and I use mine to power the microwave, a 1000W kettle and a 1250W coffee machine on a regular basis. My battery power comprises two 110Ah gel batteries which gives me the same useable amp hours as three 110AH lead acid batteries due to them being able to be discharged down to 10% capacity, as opposed to 50% for lead acid.

No it doesn't. Of course you can discharge a lead acid below 50%. Yes it will have an impact on the life of the battery, but so will discharging a gel or even a lithium battery below 50%. Given that a lead acid (or gel) battery has a lifespan of between 1000 and 2000 charge and discharge cycles, that's not a big deal, especially when you consider those figures are for discharging down to about 20% each time and then fully recharging. In reality leisure batteries rarely go through this complete cycle. Even then the battery does not die a sudden death, as the battery, be it lead acid or gel ages, its capacity will start to reduce. The quickest way to sudden death of a lead acid, gel or lithium battery is to fully discharge any of them.

Discharge levels are not the only consideration when looking at battery life. Charge and discharge currents play their part as does temperature as well as a number of complex factors.
 
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