Inverter size......? (5 Viewers)

[ianp]

I know its really an how long is a bit of string question but....... what is a good size inverter to fit for two people......?
We currently have 200ah of lithium and could / may uprate that to 300ah. But a 6amp output @ 240v (1600va) is a DC input of 150amp. Do I really want to be dealing with larger DC currents and /or is 6amp AC sufficient generally or do I need access to mre generally and if so how much?

 

[Lenny HB]

You need to tell us what you want to run with the inverter.

 

[ianp]

You need to tell us what you want to run with the inverter.

Thats the piece of string.....and its never fixed or fully known......!
Hair dryer, styling brush, kettle, a couple of laptops, maybe a cooking aide of some kind.....a fridge freezer....etc etc......
The real question is what suits for most other peeps.....not the ones who are fully electric nor the ones that wear hair shirts......!
A lot of EHU are rated at 6amp I believe and this does for most....but would I be selling myself short if I went this way?

 

[Tombola]

Hair dryer, styling brush, kettle, a couple of laptops, maybe a cooking aide of some kind.....a fridge freezer....etc etc......

MisterB has the lot along with others here

I have 400ah lithium, and run, induction hob, microwave, fridge if Im in spain, 20v laptop, wifes hairdryer, tv, and wifes cpap machine, yadda yadda,

all depends what you want/need to use, if you do want to use the part I quoted above then yes, 3000w, inverter, big cables, plenty solar, and b2b, I use the renogy inverter with auto ups, wired to my sockets, but can isolate the fridge.
I use very little gas, but plenty people can get away with 100ah and 100w of solar.

 

[autorouter]

There are a lot of useful appliances that need about 1000W: coffee machine, hair dryer, microwave, low-power kettle etc. Many people fit an inverter in the 1000W to 1600W range, which will power one of these at a time, and are quite happy with the results. These are all used in short bursts, not sustained for hours. A 500W fan heater left on indefinitely will soon drain the batteries. The current requirement of 80A to 140A is reasonable, especially if the wires to the battery can be kept short and thick.

For higher power appliances, or multiple appliances at the same time, an inverter of 2000W or 3000W can be fitted. This is a more serious undertaking, with hosepipe-sized cables and big fuses. A 3000W inverter requires a supply of 250A and a 300A fuse. The cable thickness is decided by the amps, not the volts.

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[Ray-Vic]

In short, what you want to use determines the size of your inverter, how long you want to use it for determines your battery. I use an air fryer which is the highest current appliance I use (excluding hot water), so I sized my inverter at 2,000W to make sure it would cope with this. I have a 300ah battery because I don't want a 20 minute stint with the air fryer to drain it down too far (and it also has a 200A BMS).

 

[acenip]

I'm sure if I should ask a question in this place or start a new one.I have just bought a Pure sine 1500w inverter to have my 135ah leisure battery die a week later. So I need to decide what to do regarding replacing it. Would 2 135ah acid leisure battery do my job or would I be best buying a decent size lithium battery. My only heavy use would be occasional microwave 800watt.

Thanks

 

[MichaelT]

I'm sure if I should ask a question in this place or start a new one.I have just bought a Pure sine 1500w inverter to have my 135ah leisure battery die a week later. So I need to decide what to do regarding replacing it. Would 2 135ah acid leisure battery do my job or would I be best buying a decent size lithium battery. My only heavy use would be occasional microwave 800watt.

Thanks

Lithium and more solar. What's the max draw on microwave as on startup they may pull double that.

 

[acenip]

I think it's 800w but as you say could be way more to get going. Would choosing a lower power setting help this, albeit adding to the cooking time. Sorry if this sounds naive

 

[Bessy765]

We have 700 watts of Solar, 2 x 100 amp Transporter Lithium and a Victron 12/2000/80 inverter charger. This allows us to use a Tassimo machine, microwave and when hot and plenty of sunshine the Dometic 2200 a/c.
Obviously within limits, and whatever energy you use has to be replaced. What ever size battery bank you have more capacity you can use it for longer but takes longer to replenish. On our system we have no B2B as the installer stated it was not required can pull over 90 amps from the alternator run the hab a/c whilst driving the only stipulation was if stationary and just running the engine to charge the batteries (which we never do) not to do so for more than fifteen mins. He guarantees the installation for 5 years and the batteries for 10. Four years down the line and over 20,000 miles no problems.

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[MichaelT]

I think it's 800w but as you say could be way more to get going. Would choosing a lower power setting help this, albeit adding to the cooking time. Sorry if this sounds naive

I'm not sure but it's obviously killed your battery

 

[acenip]

I'd say at almost 8 years old it didn't take much. Hardly a helpful comment though.

 

[Raul]

I'd say at almost 8 years old it didn't take much. Hardly a helpful comment though.

You killed the battery with heavy load. Way to much. Lead can give 1/10 of its amps on continuous load.
If you want a 1500w inverter to run at full power, you will need a 4500wh battery, thats 350ah of lithium or if you like lead, 1250ah. Take your pick.

 

[jumar]

I'd say at almost 8 years old it didn't take much. Hardly a helpful comment though.

But he was only telling the truth....now's the time to evaluate everything....so much has moved on....and lithium prices are dropping...
I chose Lithium and believe me it's a game changer...

 

[LostInSpace]

what is a good size inverter to fit for two people...

You could do what we do. We have a 300 watt pure sine wave inverter for the laptop.

We go on an Aire or campsite with EHU if we want more than that.

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[Tombola]

I'm sure if I should ask a question in this place or start a new one.I have just bought a Pure sine 1500w inverter to have my 135ah leisure battery die a week later. So I need to decide what to do regarding replacing it. Would 2 135ah acid leisure battery do my job or would I be best buying a decent size lithium battery. My only heavy use would be occasional microwave 800watt.

Thanks

the prices lithium have dropped to lately youd probably get one cheaper than 2 lead acids but with less weight and more or at least the same usable capacity

lithium is best for your micro, if you have the means to charge it....and any other gear you may want

 

[Tombola]

I think it's 800w but as you say could be way more to get going. Would choosing a lower power setting help this, albeit adding to the cooking time. Sorry if this sounds naive

no, they use the same power but just cycle on and off, an 800w one can easily busrt to 1000w on start up

 

[acenip]

I was just looking for helpful information moving forward, the 1500 inverter wasn't used with the 8 year old battery. (bit of a red herring, shouldn't have mentioned it) I was just enquiring what battery/batteries would be most cost effective to add now that I have this opportunity. There are already 2no 100watt solar panels fitted on the motorhome.

 

[acenip]

You could do what we do. We have a 300 watt pure sine wave inverter for the laptop.

We go on an Aire or campsite with EHU if we want more than that.

Thanks for this, we wild camp all of the time. Probably 4 years now from we were on a site.

 

[Jev88]

Sunshine Solar 1500w pure sine.
Runs our 500W microwave and small toaster. TV also goes through it currently.

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[MichaelT]

I was just looking for helpful information moving forward, the 1500 inverter wasn't used with the 8 year old battery. (bit of a red herring, shouldn't have mentioned it) I was just enquiring what battery/batteries would be most cost effective to add now that I have this opportunity. There are already 2no 100watt solar panels fitted on the motorhome.

Lithium then.

 

[jumar]

Thanks for this, we wild camp all of the time. Probably 4 years now from we were on a site.

Like we do...so now's the time to look at the Fun search facility...loads of great information for people going over..
.I converted, added and rewired my Hymer with help from fun...without I wouldn't know where to start....

 

[autorouter]

I think it's 800w but as you say could be way more to get going.

If 800W is the effective cooking power, usually the number shown off in the ads, then the mains input required to produce this will be at least 1000W. The magnetron producing the microwaves is not particularly efficient. And also to produce say 400W of cooking power, it will simply cycle on and off, maybe 10 seconds on, 10 seconds off. So as far as the inverter and battery is concerned, it's still requiring full power while it's on.

 

[acenip]

But he was only telling the truth....now's the time to evaluate everything....so much has moved on....and lithium prices are dropping...
I chose Lithium and believe me it's a game changer...

What size lithium did you go for? What's your biggest item drawing power?

 

[jumar]

I bought the biggest I could fit in the battery compartment...160ah Roamer..
Biggest draw on battery...2 eBike chargers...used virtually every day....but I may have an advantage on how I maintain my off grid usage...we live in Spain...Solar Galore
Got 400w...

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[acenip]

Sounds like a superb setup. I'm just trying to get the correct battery that'll run the microwave once in a while through the 1500 pure sine inverter I've already purchased.

 

[acenip]

Lithium then.

12V 200Ah Lithium LiFePO4 or 2no 12v 100Ah Lithium. Is the an advantage having a single 200ah? Apart from the physical space of course.

 

[MichaelT]

We had 1 200ah and ran 2kw inverter, now added 280ah battery so 480 in all but they do charge to 510ah but I have 400w solar too to charge. We run coffee machine, hairdryer, remoska, air fryer, 900w kettle and toaster trying to use free lecky rather than LPG. I used 50mm cable throughout.

 

[acenip]

Impressive

When you added the 280ah does the matching thing that is mentioned often, same AH, same size same age, apply to lithium?

 

[MichaelT]

Impressive

When you added the 280ah does the matching thing that is mentioned often, same AH, same size same age, apply to lithium?

No lithium doesn't need to be matched, the original is a KS energy underseat battery and the new one 280 fogstar. Just join them via a busbar and the solar and shunt see them as 1 battery.

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