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Quote: Originally posted by hartfordxxl100 on 21/06/2005

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 Totaly agree use one for laptop. Modified sine wave can damage rechargable batteries.and should not be used for microwaves.

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Why can the Modified sine wave inverters damage rechargeable batteries ?

Quote: Originally posted by jockthescot on 21/06/2005

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Unless I had.... a wild battery bank 10 X 110 Ah YOU had me going there for a minute!

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I kid ye not

I have a 300 w inverter which we've used to run a dvd player, charge mobile phones & shavers. (Our small b&w telly has a cigarette lighter plug anyway.)

Also used it a couple of times for the slow cooker (115w), the 85 aph battery lasted just long enough to do the curry. Only did that on a Sunday as I knew I could recharge it when we got home, bit of an experiment really.

I'd say now it was an expensive toy I could do without, bought it mainly so I could charge the phone when away more than a couple of days without EHU. It would probably have been better just  to get a charger for the phone with a cigarette lighter plug.

Quote: Originally posted by srnet on 21/06/2005

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Quote: Originally posted by Omega99 on 21/06/2005

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It is.  60Watt at 230 Volts that is.

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It might be labeled as 60W at 230V, but it cant actually be consuming 60W.

If the current from the battery is 4.1A the load is actually consuming more like 40W.

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How do you work that out?

Hi Omega

If it were consuming 60W at 240v it would be showing 1/4 amp consumption at 240V

If you were measuring the 12v Supply to an invertor it would be showing aprox 5.5 Amps, Thats 60 divided by 12v then addd 10% for invertor inefficiencies.

I know that 12v is not actually spot on 12volts and 240v could be anything from 220 to 255 depending on where and when you measure it.

Hi Caz

Phone chargers cost £20 and only useful for a particular phone, would be no good at all for dvd or any other appliance, But a 150w Invertor (which would cover all the stuff you named costs £15, a 300 watt usually under £30) and covers all the mains articles you mention and far more besides.

Quote: Originally posted by jockthescot on 21/06/2005

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Before I bought a EHU(not off ebay, Thanks GT I didn't die) I used my 150w inverter to charge my laptop, mobile phone & spare camera battries(whilst driving around) no problems with flat car battries. It worked out cheaper than buying one of those multi connectors from Maplin. Someone can have mine for a 10 quid donation to The British Heart Foundation. It would cost about 3 quid to post, I'll pay.

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Jockthescot

I would be quite happy to pay the BHF a £10 donation for your inverter as this is a charity we support strongly. I have been looking to get an inverter from Ebay just to charge up our phones and camera batteries (LI 12B) while  away without EHU.

Why can the Modified sine wave inverters damage rechargeable batteries ?

I got the information from a disclaimer in the packaging, with a reasonable quality inverter.

Maybe they were covering all eventualities

MODIFIED SINE WAVE is a sales term used for a modified square wave type of AC power which is not quite the same as power company electricity. Modified wave inverters are lowest cost, slightly more efficient, and almost all appliances work fine with them, though some may hum louder. But a few sewing machine speed controls have difficulty on modified sine wave. It can also damage photocopy machines, laser printers, and some cordless tool rechargers. Recently we found the first TV that would not run on any modified wave inverter. Battery chargers in some modified waveform inverters may require the highest quality generator (about $3000 and up) to charge effectively, or addition of a 10% voltage boost transformer.

http://www.backwoodssolar.com/Catalogpages2/InvModSine.htm

Hi

only certain types dont like it, like the indirect charging on toothbrush batteries