Inverter

Chris356

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Hi I have fitted a 2500w inverter into my van and plan to connect it internally to the hook up lead so that all the sockets in the van are live and the aircon, now obviously I will run the fridge and heating on gas but would it be worth leaving the onboard charger switched on will it put any charge into the batteries
 
No it isn't a good idea to leave the onboard charger on, it is a waste of energy trying convert 12v to 230v to charge the original 12v, the inverter uses power so you would never put back in the extra you are using
 
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Are you serious, have you thought how much power is required to run an inverter, unless you have a large battery bank you will soon run out of power especially if you run the air con.
 
Regardless of your intended use, how are you going to connect it? the only way to do it safely is via a changeover switch preferably an automatic one ,the inverter MUST NOT be connected to or be able to be connected to the interior 240v system at the same time as the mains input from the hook up lead at best you will blow up the inverter at worst you could be looking at a very expensive mistake
 
Hi the inverter is a waeco intended for a Aircon unit it also has a 240v input to automatically switch off the inverter I have just got the 1 socket wired at the moment and only used it for the toaster and kettle whilst on the move
 
You will require a very large bank of batterys to run that baby,around 400ah for starters if you are planing to run for more than about 15 mins.
 
If you have say 400Ah of batteries, you will be able to use the inverter for a while, but then comes the hard part - how do you recharge the battery when they get way down.
 
I have 2 x 100 amp batteries how long will it take to charge them with say a 150 amp alternator
 
I have a Truma inverter (air con type) and it is wired 'inline' on my 240v. I have mine connected to the socket output of my vans RCD protected socket MCB. By doing it this way it does not supply power to the charger, fridge or water heater when the inverter is running, but does power the internal sockets. I also have 660Ah of batteries.
 
Chris356 said:
I have 2 x 100 amp batteries how long will it take to charge them with say a 150 amp alternator
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The size of your alternator is irrelevant. The battery won't charge at 150amps, or if it's flat and does it will burn out the alternator and battery.
You really don't want to be running an A/C compressor from 12v. My 3.5kw (heating not electrical watts) Mitsubishi unit at home runs at about 6amps when running flat out so that at 12v would equate to something like 120amps plus inverter inefficiency.
 
Inverter problems

Hi guys, the 2500w inverter is just about large enough to run a toaster on its own, Or maybe just about a microwave on its own. If you intend to plug and play many different things you will need an inverter about 5 times the size, at least 10,000w modified sinewave. Even then you will need to keep an eye on the specific types of appliance you use with it, as some types of electrical items will not like the wave form (for example toothbrush chargers will be damaged). I have a 8000w inverter which is just about sufficient for what I am doing. I have a 1770 AH capacity battery bank, with a separate pair of vehicle batteries another 220 AH. All these are solar charged by two sets of three 100A flexible solar collectors. 600a in total controlled by two waterproof MPPT controllers. The reason for this is, if I am parked near trees, a shadow might knock out the output on one set of panels, rather than loosing all solar production. I would never connect the inverter to the air conditioning It will pull vast amounts of amps and will drain the batteries in a surprisingly short time. I will attempt to explain why, 240volts * 10amps = 2400Watts almost the limit of the inverter, but motors use more amps on start up to physically get turning from a stand still, but I will ignore this point for now. to achieve this 2400watts / 12volts = 200amps. The draw from 220 AH pair of batteries, theoretically would last just over the hour, but in reality the usable range is 13.5v fully charged to 10.5v discharged, to exceed this range will damage the batteries. So the usable range at max is 3V and the inverter will cut out. The time this takes to happen will depend on the quality, electrolyte level and general condition etc of the batteries, and so I would be surprised if you got more than 20 mins. You can never use the battery charger at the same time, the inefficiencies of the inverter and charger will combine and flatten your batteries for you in next to no time. I Have an onboard generator for any Air-con, intensive cooking, hair drying women etc. The inverter is used for microwaved quick snacks, super quick cut of tea with the electric kettle etc. Most of the time we use 12v appliances or gas. Even with training in power conservation the 5 of us use power at an enormous rate. I regret to bring more bad news about your inverter but any appliance more than around 1000w will probably cause it to trip out if you are lucky, if you are unlucky it won't trip out, just melt down inside. The problem is with the initial start up I mentioned earlier. My best advice is to research your exact requirements and list them out, then do some more investigation on the internet what size inverter is required for each item and choose the biggest affordable inverter to run the specific must haves and scrap the idea of plugging in multiple items.
 
My inverter only takes current from the batteries when no mains is present. The bank was drained once, when I was unaware that the mains supply had been cut so I split the supplies to high energy devices (air con, heating, kettle, …) so that they only took current from the mains. Less power-thirsty devices (fridge, microwave, sockets, …) were fed through the inverter. As others have said, you need (thick wires and) a hefty bank of batteries to run an inverter of that size, especially for any length of time.
 
Chris356 said:
I have 2 x 100 amp batteries how long will it take to charge them with say a 150 amp alternator
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Depending how far down they are,so say you took them down to 50% which will leave you at 100ah to recharge,with alt at 150ah about 45 mins give or take to make sure there well toped up.
But no alt will charge at that rate cause it would boil the battery and in truth you could double or treble that time ,also remember at dusk or night you will be running lights on van slowing the charge rate down even further,think you require a genny.
 
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We managed happily for two weeks in April with 2 x 75 amp habitation batteries and a 150w solar panel. I have a 300w Pure Sine wave inverter that powers SWMBO's Electric Blanket. Everything else runs on 12v or Gas. Air-conditioning we have 12v fans and open windows. Keep the van cool by closing the blinds and keeping the sun out.

A 2500w inverter is going to need some serious cabling. 200 amp cable is rather large. You will also have to watch the lengths of cable because you are going to get a voltage drop. Best place is next to the battery bank.

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You need a solar collector on the roof to heat water that then drives a absorption a/c system. Simple.
 
Inverter problems

If noise is not an issue I would use the generator all the time, but other fellow motorhome owners do not appreciate being woken up at our breakfast time. So I have the 8000watt inverter it is big enough to run a toaster and microwave together, we can do a full English without making a sound. I then switch off the 240v, I only switch it on when necessary. We have 4x12v leisure batteries supplying power to satellite, and 2 DVD TVs with a separate entertainment system and internal LED lighting, all this can run constantly all day and the 6x100Amp solar system will replace the inverter drains and will keep up on a cloudy day. I also use a heat exchanger that will heat up the 10 gallon tank of water if driving from the hot engine cooling system. I am exploring the viability of increasing the water heater function with a 12v 300watt immersion heater that could be run off solar and save the gas, but there are a couple of small issues that need to be worked around, so as to not effect the existing systems. Should be ok with a bit of work. I will update here if I put it together. I can be completely off grid, only needing to dump wastes and refill fresh tank.
 
QFour said:
We managed happily for two weeks in April with 2 x 75 amp habitation batteries and a 150w solar panel. I have a 300w Pure Sine wave inverter that powers SWMBO's Electric Blanket. Everything else runs on 12v or Gas. Air-conditioning we have 12v fans and open windows. Keep the van cool by closing the blinds and keeping the sun out.

A 2500w inverter is going to need some serious cabling. 200 amp cable is rather large. You will also have to watch the lengths of cable because you are going to get a voltage drop. Best place is next to the battery bank.

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The inverter came with 2 X 1 metre lengths 15mm diameter in red and 2 X the same in black so prob 30mm in total and I only carry 1 gas bottle now so I've put the inverter in the gas locker then we can't hear the fans running it has a remote switch then I don't have to keep going outside to switch it on
 
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