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Inverter brands and sizing


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Not boating but a land yacht/ motor home question, currently looking to fit an inverter in a traillite motor home to charge a couple of e-bike batteries, charger is drawing 1.65 amps at 240 volts, out put is 4 amps at 36 volts,  current battery setup is 260 amp  from 2 AGMs, was thinking 1500 watt inverter,  it might be asked to run the wife’s hair drier briefly couple times a week, any info on brands and sizing would be appreciated, cheers

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your ebike charger consumes around 400w.  Hair dryer is probably four times that.  Derate the inverter by 2x for safety, you need a 1000w for the bike charger or a 3kw for the hair dryer.

I bought a cheap chinese one off aliexpress, labelled as 2000w.  It runs power tools fine until I load it with the circular saw...  I reckon it would cope with your wife's hairdressing routine.  Trick is making sure the supply cables are suitably beefy.  At 1500W and assuming 12V system you are pullling down a lot of amps!

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Ok , i was looking at a projecta 1500w or mastervolt, want something with a remote for off on, was going to mount it in the boot and run heavy cable, 50mm ?? (may have to up size to 75mm)To batteries, approx 6 mtr run, i would try and do my charging whilst driving, mitsi canter has a 140 amp alt fitted, also planning to add more solar 

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Another option is i can mount it behind batteries in the locker , then run a 240 volt lead down chassis rails and exit it into the boot, save alot of $ for heavy cable

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Always go larger than you think you need 

You will find other uses once you have it

mounting in battery box is a good idea, however you need to fit a 10 amp breaker on the 230v side as close as possible to inverter

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For battery charging via an inverter, you'll need a pure sin wave one, not a cheaper one that has an approximate sin wave.

Most inverters and generators have a peak power and continuous power number. You want to stay within the continuous power rating, that gives you an appropriate safety margin within it's stated specifications.

Motors like Aardvarks skill saw have a high start up current (If I've got my terms right it is a high impedence). Motors such as pumps / skill saws can draw up to 8 x the running amps on start up. This may be what trips Aardy's inverter with the skill saw. The Admirals hair drying on the other hand will have zero impedence / start up current, but will draw plenty of power. It may be cheaper to get the Admiral a lower powered hairdryer, i.e. a travel one that is say 700w instead of 1,500w. There are 12v hair dryers about, but I wouldn't bother, they just don't have the power rating.

Whilst there is logic in what the others say about going bigger than you need, if you are clear about what you will run off it, it is possible to match the rated continuous current with a device that draws that. Noting that just cause a device says it is 1,000w doesn't mean that is what it actually draws. I have a workshop vacuum cleaner with a 1,000w rating, tested it on a power meters (the $10 plug into the wall socket type) and it was giving between 1,120 and 1,080 watts depending on the load. That said, I have been comfortably running it off my inverter generator that is 1,000w continuous and 1,200w peak. And noting a vacuum cleaner is fairly low impedence. I wouldn't trying a 1,000w skill saw off a 1,000w inverter / generator, as the high impedence will cause trouble at start up.

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Im definatley going pure sinewave, my brother inlaw charges his 750 watt ebike with a 600 watt inverter, via 200 amp DC battery using solar, so thought 1000 watt inverter should be adequate, im not planning on lithium upgrade anytime soon so dont want to damage my AGMs with to bigger load

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Converting from 12vdc to 230vac and back to 36vdc is extremely inefficient. 

Unless you have excess energy to literally burn, you'd be better off getting a 12v to 36v boost converter. You'll possibly find the manufacturer even sells a correctly sized boost converter.

If you're buying an inverter that needs a 10A circuit breaker installed on the AC side, then legally this must be installed by an electrician and include appropriate earth/neutral protection.

If you're buying an inverter with a 3pin AC socket on it, then these use a isolated IT earthing system and do not need an additional breaker installed as they have internal protection.  If using one of these devices then you should never run multiple devices off a single plug. 

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Thanks @CarpeDiemI have looked but i can only use the bosch charger supplied with the bike and it reqs 240 volt, i do understand the need for a registered sparky if hard wiring from inverter to a power point, it would be easier if i could mount invtr inside van but my wife doesnt want it spoiling the look

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58 minutes ago, whitepointer said:

but my wife doesnt want it spoiling the look

WAF is an important specification across  a wide range of toy instalations in my experience.

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