Inverter issues

[lorger]

Just had a 2000w pure sine inverter fitted and having slight issues, when fitted last week all worked well. Today I went to demonstrate it working and had issues, I used our travel hairdryer which is 1200w and it works no problem on setting 1 but as soon as I turn it up to setting 2 it runs for 30secs stops then for 10seconds and repeats this.
My battery is fully charged, we then tried it in my friends inverter which is exactly the same and it works no issues.
The guy who fitted is on holiday so don’t want to pester him if it’s a simple fix.

 

[lorger]

Just now the inverter has started to beep with nothing switched on, if I switch it off and on the fans come on then 5 seconds later the beep and red light starts

 

[Tombola]

Cables thick enough? and is the fuse getting hot if it senses too much current/heat it will cut out then start again when cools.
what inverter is it,

are you sure the battery is full, and what fuse are you using

 

[pappajohn]

How many watts on setting 2 ?

 

[jezport]

What make is the inverter. Many cheap brand inverters are nowhere near their quoted Rating.

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[lorger]

Cables thick enough? and is the fuse getting hot if it senses too much current/heat it will cut out then start again when cools.
what inverter is it,

are you sure the battery is full, and what fuse are you using

Cables are the ones that came with it and although they recommend them I am doubting they are, here are the cables. The fuse has a trip on it.
Battery is full according to my van monitor my Victron monitor and the battery app plus the inverter has battery reading.

 

[lorger]

How many watts on setting 2 ?

1200w, I’ve plugged it in to my friends identical inverter and all works.

 

[lorger]

What make is the inverter. Many cheap brand inverters are nowhere near their quoted Rating.

As above friend has identical one and it works plugged into that, only difference is he’s had it 18months.

 

[lorger]

Forgot to mention cable run is about 18inches

 

[cmcardle75]

Cables are the ones that came with it and although they recommend them I am doubting they are, here are the cables. The fuse has a trip on it.
Battery is full according to my van monitor my Victron monitor and the battery app plus the inverter has battery reading.

Looks like a cheap far eastern make. Likely described with "exquisite quality". However, even then, it is more likely your batteries that are the problem than the inverter. A typical 110Ah lead acid leisure battery is good for 300W. If you try to run 2000W off it, it is likely to complain in no uncertain terms. In reality, if you want 2000W+ mains appliances, you need lithium batteries, or about half a tonne of lead acids.

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[nabsim]

I found 16mm cable getting warm pulling enough current for 800W on a 1500W inverter, stone cold with 24mm cables. Are the cables flexible or stiff, they are not all equal?

 

[jezport]

As above friend has identical one and it works plugged into that, only difference is he’s had it 18months.

Cheap ones are hit and miss, one may work yet the next 3 probably won't.

 

[pappajohn]

1200w, I’ve plugged it in to my friends identical inverter and all works.

Manufacturing tolerances.....
1200watts is too high for that particular inverter.
It may have a max of 1150w or less.

 

[St3v3]

Cheap ones are hit and miss, one may work yet the next 3 probably won't.

I agree. I had a cheap inverter because someone else had one for a year and it was good.

It wasn't (similar problems to OP actually. )

I now have victron.

 

[lorger]

Looks like a cheap far eastern make. Likely described with "exquisite quality". However, even then, it is more likely your batteries that are the problem than the inverter. A typical 110Ah lead acid leisure battery is good for 300W. If you try to run 2000W off it, it is likely to complain in no uncertain terms. In reality, if you want 2000W+ mains appliances, you need lithium batteries, or about half a tonne of lead acids.

I have lithium

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[lorger]

Manufacturing tolerances.....
1200watts is too high for that particular inverter.
It may have a max of 1150w or less.

It’s a 2000w with 4000w surge surely that would do for 1200w

 

[St3v3]

It’s a 2000w with 4000w surge surely that would do for 1200w

My 3000w cheapo wouldn't reliably run 600W...

 

[cmcardle75]

I have lithium

Assuming it is a reasonable amount of lithium, with a suitably sized BMS (150A+), and the cables are all thick enough, it sounds like the inverter isn't quite living up to expectations.

 

[Raul]

If inverter pauses, then resumes, it’s clear indicator that your batteries can’t sustain that load for to long. Voltage sags, inverter trips out, then voltage recovers and starts again. The cycle repeats.
What batteries do you have that you attempt a 1,2kw load?

 

[lorger]

If inverter pauses, then resumes, it’s clear indicator that your batteries can’t sustain that load for to long. Voltage sags, inverter trips out, then voltage recovers and starts again. The cycle repeats.
What batteries do you have that you attempt a 1,2kw load?

I have 125AH lithium, the other MH with same inverter has 2 100ah lead acid batteries and works fine with them.
Possibly think as folk have said inverter not up to it, will return and purchase better one.

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[cmcardle75]

Assuming it is a reasonable amount of lithium, with a suitably sized BMS (150A+), and the cables are all thick enough, it sounds like the inverter isn't quite living up to expectations.

It should be noted that 1200W is basically 100A, which is a common size for a BMS. What current does your BMS cut out at? This is not particularly related to your battery capacity.

 

[St3v3]

, with a suitably sized BMS (150A+),

Actually lorger , the above is also a very good point.

 

[Raul]

Very likely to be the bms limit. With the inverter conversion inefficiency, the 1200w output, will eat more than 100a dc. And 100a with 16mm2 it’s not very efficient either, probably some voltage drop there as well, increasing the amps demand even further.
If you can return it, do it asap, and buy decent next one.

 

[lorger]

It should be noted that 1200W is basically 100A, which is a common size for a BMS. What current does your BMS cut out at? This is not particularly related to your battery capacity.

What’s a BMS?

 

[Raul]

Your lithium battery has a battery management system BMS inside. The battery spec should specify what A bms is. Could be a 100a bms despite the size of the battery, if you exceed the bms rating, it will cut out.

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[St3v3]

What’s a BMS?

What make and model battery do you have?

 

[lorger]

KS energy can’t remember the exact model might be low profile

 

[lorger]

Your lithium battery has a battery management system BMS inside. The battery spec should specify what A bms is. Could be a 100a bms despite the size of the battery, if you exceed the bms rating, it will cut out.

So in that case it wouldn’t matter how good the inverter was, if I doubled up on the battery does that double the A or would it still be the same.

 

[lorger]

Battery has 150a output and I think if I remember correctly the device was drawing 155a, I assume that’s the issue.

 

[funflair]

Personally I think that the cable is well undersized, OK it's a short run but that's the same size as I have on my solar install running a lot less amps, doesn'r sound right to me.

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