power inverter question

Potluck

i have a 2000w power inverter connected to the battery of my van. when i used high power items for a long period of time, like my laser printer i keep the van running so that my battery does not go flat, but it has caused problems to other vans that i have had in the past.

What i want to know is, would it be possible to buy a small generator and have the generator charging a 12v battery that is then connected to my power inverter and if so what size generator would i be able to get away with?

*Kol*

Why would you connect an inverter to a gernerator? The generator will provide 220v to plug directly into your MH. Then you can plug in your laser printer to the 220V sockets in the MH.

Another option is to get a DC to DC transformer which would be less of a strain on your battery (thats assuming your printer used a tranformer from 220v to XXv DC)

Edit: I'm assuming you have a MH or do you use a printer for work in your van?

Potluck

i don't have a mh i work from my van. i want a way to keep a charge on a battery so i don't have to have the van running, also it has to be quite!?
i've seen generators with a 12v battery charger connection, but i don't know if this is just for slow battery charging or will it keep a charge topped up like an alternator in a car/van?

stapeler

Have you considered a fuel cell? they're not cheap but worth considering http://www.efoy.de/index.php?option=com_content&task=view&id=13&Itemid=56 ,

Potluck

i never even herd of them. that site does not give me to much info.
what price are they?
how do they work/recharge?
would they run about 2000w for around 8 hours?

stapeler

Their FAQ section http://www.efoy.de/index.php?option=com_content&task=view&id=898&Itemid=286 gives more info. Their big advantage is the quiet operation and zero emissions. Their largest unit seems to produce around 1600 watts per day. There's a few other sites out there selling them and you're probably looking at around €2000ish plus the cost of fuel cartridges:(

Potluck

after reading that i don't think a fuel cell would do for what i need. i need to power about 1500w-2000w for about 8 hours at a time! thanks for the help, interesting to know.

peasant

Do a search on ebay for KIPOR generators. A digitally controlled 2000 Watt silent "suitcase" generator should set you back about 400 -500 euro ...problem solved.

Potluck

i have looked at them generators, i think it is the best option. how loud would it be when running, say compared to a 2.5 deisel engine in a fiat ducato (van i have)?

*Kol*

Potluck wrote: »

i have looked at them generators, i think it is the best option. how loud would it be when running, say compared to a 2.5 deisel engine in a fiat ducato (van i have)?

They are really quiet. you wouldn't even notice it.

derry

Potluck wrote: »

i have a 2000w power inverter connected to the battery of my van. when i used high power items for a long period of time, like my laser printer i keep the van running so that my battery does not go flat, but it has caused problems to other vans that i have had in the past.

What i want to know is, would it be possible to buy a small generator and have the generator charging a 12v battery that is then connected to my power inverter and if so what size generator would i be able to get away with?

The issue has not been stated properly in terms of time

For example a 1000 watt generator connected to 200 amp battery would work well for one hour but not four hours

2000 watts is a lot of power
it ~12 volts X ~166 amps

a typical car battery should only draw down at 10% of capisity

the invertor has losses about 10% so 166 amps +16 amps 182 amps

If we want 166 amps we will need 10 x 180 amp batteries or about 9 200 bateries to supply this power for 10 amps for 10 hours


Clearly anything less than this will damage and wreck the batteries like demanding 180 amps from a 200 amp battery or worse 100 amp will kill it dead in a few minutes


Howeveer you are probably only suppling some few hundred watts toa main computer usualy 200 watts and the printer takes it power from that say another 200 watts making 400 watts

that more like 50 amps which a 200 amp battery can tolerate for short periods

The van alternator will tyicaly be 65 amps but isnt meant to supply 50 amps for long periods as in normal use the alternator has the battery charged in 15 minutes and supplys a steady 5 amps after that

The time factor is what is important

A 1000 watt generator connected to a 200 amp batterry( looks big like two big car batteries ) will stem the demand somewhat
1000 watts at 12 volt x 83 amps

In the real world there is losses and a 1000 watt is peak 1000 and about 800 watts continios so 50 amps is probably real world stuff

So if the demand from the system was 500 watts your power going in would be very marginal due to loses charging battery which is about 50% losses

We would estimate the deamnd of 400 waats from acomputer and printer would be maximum with a 1000 watt generator
500 watts demand might cause the battery to run down slowly but still work for a few hours

That why time is important

If you want say like 16 hours running better to get 3000 watt generator The other isue is connecting a computer to generators often blows computers as generators are dirty signal power

Passing the generator through a battery charger through to the battery and through the Invertor will smooth out the bad signals from the generator

However a 20 amp battery charger costs like 100 euros in Halfords



The other solution is to get a voltage stabilizer that will smooth out ragged edge 1000 watts of 220 power to smooth 220 volts but that to do 20 amps costs like 200 euros
other solutions is to make 220 go back down to 12 volts and attach to batterry but 20 amp type will cost 100 euros
Power stabiliser 220 to 12 volts available from www.greenhobbymodel.com

then the issue of the generator

A cheapo Aldi or Lidl one will cost 150 euros for 1000 watts

For a cheapo Aldi or Lidl one will cost 300 euros for 3000 watts

when these break spares are nearly impossible to get and they only seem to last a few weeks or one camping holiday


Honda 1000 watt will cost like 999 euro
Honda 2000 watt will cost like 1200 euro

These are quite and last for donkeys years and more easy to get spare parts

For reliable power year after year the main name Honda or Yamaha etc are where it is at available from www.greenhobbymodel.com

The 1000 watt genertors have a 8 amp battery charger to charge the battery but that is only 100 watts of power at best and I never seen more than 4 amps from those toy thing so 40 watts is best case so forget that feature

Its better you come back state what battery you have in amps and is it deep cycle lead acid flooded or lead acid RSLA ( Recombining sealed lead acid )AGM( Acid glass mat )

Then also what computer with what watts like tower with 200 watts
or laptop ( often 70 watts but bigger ones 120 watts )

is the printter driven from 220 volts or is the power feed from the computer through the 5 volt USB or does it have its own 18 or 22 volt volt transformer on the 220 volt leads like a laptop has

Also how long will the equipment run

Serousily the Van engine uses so little fuel ticking over and supplys are often ~65 amps possibly 100 amps but if its a small car type compact size vann the alternator migh only be 35 amps

Replacing alternator with 160 namps or 200 amps will often sort most problems
On ly one rule start engine straight away dont let batttery run down as a semi dead battery wont smooth out the voltage spikes like a full battery will


Derry