Inverter to charge 540ixp

[openspaceman]

1 hour ago, Acerforestry said:

You might have to explain that to me, lol I don't quite follow. If say, I charge any small electric appliance or tool from 12V on the move, how is that not costing less than the mains at home? Particularly given current and projected costs

Because the power for the charging comes from your vehicle alternator and that in combination with the engine  and inverter conversion efficiencies are not as efficient as the grid electricity and a charger. Also DERV or petrol is highly taxed compared with the grid.

 

Okay it is a small amount of extra power from your engine but  it is more.

 

A test would be to listen to an idling engine as you  switch  the charger on.

[Canal Navvy]

The alternator on your vehicle adds load to your engine which adjusts by burning more fuel. The fuel you are burning carries road tax and electrical generation from internal combustion is reckoned to be 30% efficient on a dedicated direct coupled set 😒

 

Currently the most expensive electricity is coming from gas fired power stations that are up to 60% efficient and don't pay road duty.

 

You have further inefficiency by having to convert the nominal 12 volts DC to 240 volts AC and then back to the charge voltage of the batteries on your tools. 

 

Having mains voltage out on site can give operational efficiency but in itself can't be cheaper,  conservation of energy and all that .....or don't get owt for nowt 🙂

 

Cheap inverters are cheap for a reason and their "dirty" waveforms don't go well with electronics, a lithium battery charger is most definitely electronic 😁

 

[Stubby]

8 hours ago, openspaceman said:

 

 

A test would be to listen to an idling engine as you  switch  the charger on.

You can even hear the change in engine note at tickover  when the AC cuts in .

[Canal Navvy]

1 hour ago, Stubby said:

You can even hear the change in engine note at tickover  when the AC cuts in .

Air con is pretty power hungry, a fairly common hatchback like the VW golf has 8kW of cooling while having an alternator of 2kW.

 

[Acerforestry]

Ok that's confirmed that in theory you lose a little on mpg - I'm able to use recycled veg oil mixed with derv to a degree in my old truck so I'm still coming out more than on top in that respect (and at present that's perfectly legal, before anyone asks!), and I'll be interested to see if the inverter can be used with the vehicle stationary for spells of say up to 30 mins, on one click of the key. As to if what extent that will deplete the two batteries (winter pack), I don't know yet

Edited September 11, 2022 by Acerforestry

[Sutton]

10 minutes ago, Acerforestry said:

Ok that's confirmed that in theory you lose a little on mpg - I'm able to use recycled veg oil mixed with derv to a degree in my old truck so I'm still coming out more than on top in that respect (and at present that's perfectly legal, before anyone asks!), and I'll be interested to see if the inverter can be used with the vehicle stationary for spells of say up to 30 mins, on one click of the key. As to if what extent that will deplete the two batteries (winter pack), I don't know yet

We can calculate how long it'll take you to get your money back for you - just give us some imput first:

What amp is your alternator?

What inverter price range are you looking at?

What is idle rpm of you diesel and what size?

What batteries are wanting to charge?

 

[Acerforestry]

25 minutes ago, Sutton said:

We can calculate how long it'll take you to get your money back for you - just give us some imput first:

What amp is your alternator?

What inverter price range are you looking at?

What is idle rpm of you diesel and what size?

What batteries are wanting to charge?

 

Ok, that's pretty decent of you, I'll get the info by tonight. Though given the cost of the little inverter  (50 quid)

I'm more than happy since that can be used to charge or power all manner of stuff, on the move. Tried a 4 inch angle grinder on it yesterday, it handled that ok

[dumper]

Angle grinders run on most inverters they use a lot of juice but are not fussy chargers and variable speed drills need a good inverter our van one was  £660 before fitting it runs computer drill and chargers like plugged into the mains also needed a second battery angle grinders were using to much power

[coppice cutter]

Most vehicle charging systems actually produce more than is required a lot of the time and the excess is converted in to heat which is then lost via some sort of regulator.

 

So in theory, using the vehicle to charge something, especially at a time of low electrical demand on the vehicle, may simply to using energy that would just have been lost anyway.

 

So it's not a straightforward equation.

[lurch_917]

On 09/09/2022 at 21:42, openspaceman said:

Because the power for the charging comes from your vehicle alternator and that in combination with the engine  and inverter conversion efficiencies are not as efficient as the grid electricity and a charger. Also DERV or petrol is highly taxed compared with the grid.

 

Okay it is a small amount of extra power from your engine but  it is more.

 

A test would be to listen to an idling engine as you  switch  the charger on.

the benefit is he is already running his engine whilst driving to the job . and as most alternators once they hit a certain volt/amps are just wasting energy this would actually make it more efficient .