1000w inverter problem - help !

[Two Owl Ones]

I have just fitted a Renogy 1000w inverter, we have a 100 AH lithium ion battery (1660_watt hours)
I have a couple of items that i would like to run off this, one is a swiss lux kettle @ 600w a swiss lux heater @ 500w a george foreman grill 600w and a dimplex 250w heater obviously I only want to run one appliance at at time.

Each item on its own will work but only with the engine running, (we do have 2 x 175 Watt Polycrystalline Solar Panels with a 100/20 smart MPPT controller) with the old 300w inverter could run a house blu ray player, tv and coolbox for days with no problem at all.

Do I need a bigger inverter, (2,000w)? or add a bank of batteries ? or ..... have i made an error somewhere ?

Any info or advice to help solve my issue would be greatly appreciated.

Thanks

 

[Diabalo]

I reckon you need at least the 2000w jobbie.

 

[Raul]

A 100ah lithium battery at 12.8v, holds 1280wh that’s all, not 1660wh.
I don’t understand what’s the problem?

 

[Two Owl Ones]

do you think that the 2000w would work with what ive already got? or would i need more batteries ?
thaks for the reply

 

[Raul]

I reckon you need at least the 2000w jobbie.

Why? If largest load is 600w resistive load, the 1 kw will run it ok.

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[Raul]

do you think that the 2000w would work with what ive already got? or would i need more batteries ?
thaks for the reply

Yes your battery is the limit, with the 600w load, you pushing your battery at 0.5C discharge, and within 30 mins you will be about half discharged.

 

[Two Owl Ones]

A 100ah lithium battery at 12.8v, holds 1280wh that’s all, not 1660wh.
I don’t understand what’s the problem?

hi thanks for the reply,the sticker on the battery says lithium ion 100ah 1660wh.. but will only run any of the items if the engine is running..

 

[Raul]

hi thanks for the reply,the sticker on the battery says lithium ion 100ah 1660wh.. but will only run any of the items if the engine is running..

Gotcha, it means your load is larger than the battery can support, and inverter adds it’s conversion losses as well. So the 600w may need another 120w for the inverter, making it 80% efficient. That would be a 720w, about 60a draw. A reasonable 100ah good lithium should handle that for good few minutes. Something does not sound right about the battery: 100ah and the 1660wh does not go together.

 

[Two Owl Ones]

A 100ah lithium battery at 12.8v, holds 1280wh that’s all, not 1660wh.
I don’t understand what’s the problem?

hi battery sticker says 1680wh. The problem I have is that each appliance will only work with the engine running. As soon as I turn the engine off, the appliance stops. the 1000w inverter isnt running low wattage appliances. it just cuts out.

 

[Diabalo]

Why? If largest load is 600w resistive load, the 1 kw will run it ok.

Sorry, I read the 1660 W hours as his load. my bad.

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[Raul]

hi battery sticker says 1680wh. The problem I have is that each appliance will only work with the engine running. As soon as I turn the engine off, the appliance stops. the 1000w inverter isnt running low wattage appliances. it just cuts out.

View attachment 727682

That’s sticker is wrong and suspicious. Like I said, if your battery is a true 100ah lifepo4, then it’s 100a times 12.8v gives you 1280wh of energy.
Have you tried these loads with fully charged battery?

 

[Folkranger]

Hi, I'm not going to get too technical, probably because I'm not too technical, but common sense tells me that the kettle is ok with the inverter and your battery as it's only on for short periods but I would say that the heaters mentioned are not suitable as you would be likely to have them on for longer periods and the battery does not have capacity for that sustained load.

 

[Two Owl Ones]

That’s sticker is wrong and suspicious. Like I said, if your battery is a true 100ah lifepo4, then it’s 100a times 12.8v gives you 1280wh of energy.
Have you tried these loads with fully charged battery?

yes i have tried, the solar keeps the battery topped up, in the past it hardly used anything from the leisure battery, i can use the tv, blu ray player, charge phones lap top ect.. and uses very little by way of voltage

 

[Two Owl Ones]

Hi, I'm not going to get too technical, probably because I'm not too technical, but common sense tells me that the kettle is ok with the inverter and your battery as it's only on for short periods but I would say that the heaters mentioned are not suitable as you would be likely to have them on for longer periods and the battery does not have capacity for that sustained loa

Hi, I'm not going to get too technical, probably because I'm not too technical, but common sense tells me that the kettle is ok with the inverter and your battery as it's only on for short periods but I would say that the heaters mentioned are not suitable as you would be likely to have them on for longer periods and the battery does not have capacity for that sustained load.

 

[Two Owl Ones]

thanks for the reply, even the 250w heater wont run unless the engine is running

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[Lenny HB]

Do you know what the max discharge is it for your battery? It will be set by the batteries BMS on a 100 ah battery it could be only 50 amps. Even a 600 watt kettle powered by an inverter will draw more than that.

 

[Raul]

Forget the voltage, if that 500w heater is on for 1hr, you have a empty battery. You don’t have enough storage for heating long time. The kettle is ok for few mins, and battery recovers with a bit of solar. You can’t gauge lithium state of charge by voltage reading. You need a battery monitor, like victron bmv, to count your amps in and out. Then you will have a informed and true statistic of how much you got in your battery. Forget voltage with lithium.

 

[Hoovie]

Battery sticker looks wrong, as has been said.
I wonder if the Battery, if it has a BMS ( The Label says Lithium Ion. We don't know it is LiFePO4) is current limited to a lower than typical number (some are only rated at 40A!). Given the battery label, I would have doubts about ANYTHING to do with that battery

 

[Two Owl Ones]

thank you for the reply,i have no idea what the max discharge is or how to measure it, it doesnt even appear to have a bms..i have only known this battery since we have owned the van, do you think i need a bigger inverter ? or a different battery set up ?

 

[Two Owl Ones]

Forget the voltage, if that 500w heater is on for 1hr, you have a empty battery. You don’t have enough storage for heating long time. The kettle is ok for few mins, and battery recovers with a bit of solar. You can’t gauge lithium state of charge by voltage reading. You need a battery monitor, like victron bmv, to count your amps in and out. Then you will have a informed and true statistic of how much you got in your battery. Forget voltage with lithium.

thank you for the reply, the kettle will boil in about 6-8 mins but only if the engine is running, maybe i was a little ambitious in thinking it would run a kettle or a small heater.

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[vanVhome]

I've been running a 600w kettle on a 1000w NDS inverter without problems. I've 2 x 125a AGM batteries and 3x100w solar panels

 

[Billy192]

i would just add another batt

 

[Two Owl Ones]

brilliant i have put two agm batteries in my watch list on fleabay, so i think i will swap them out and give it a go,rather than buying the 2000w inverter thank you for the reply

 

[Billy192]

stick with the lithium get 1 more 100Ah

 

[stevec]

Are you sure you have wired the inverter correctly? I have a small 400w inverter and that runs our Remoska ok (but not for too long - it takes 40A). I have two Varta leisure batteries though.

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[Two Owl Ones]

Battery sticker looks wrong, as has been said.
I wonder if the Battery, if it has a BMS ( The Label says Lithium Ion. We don't know it is LiFePO4) is current limited to a lower than typical number (some are only rated at 40A!). Given the battery label, I would have doubts about ANYTHING to do with that battery

thank you for the reply, i tend to agree,i think i will swap it out for two new ones

 

[Two Owl Ones]

Are you sure you have wired the inverter correctly? I have a small 400w inverter and that runs our Remoska ok (but not for too long - it takes 40A). I have two Varta leisure batteries though.

yes its wired correctly, i just removed the 300w one and replaced it with the 1000w renogy inverter, it runs the tv, the blu ray player and the large coolbox no problem, so i think maybe the lithium ion battery i have may be the prime suspect,thanks for the reply,

 

[BouncyBoatFolk]

Forgive me, quite new to this myself. Would it not be better to use the limited capacity you have to run the vans own gas heating?
The lithium should run the Truma/ whatever pumps for ages,leaving more power for other stuff.
Gas kettle will boil quicker than 6/8 min.
Mike.

 

[pappajohn]

The label is showing 1660wh.
It's also showing a voltage of 14.4v which is the charge voltage not the at rest/standing voltage.
My opinion....you have a faulty inverter.

 

[Two Owl Ones]

Forgive me, quite new to this myself. Would it not be better to use the limited capacity you have to run the vans own gas heating?
The lithium should run the Truma/ whatever pumps for ages,leaving more power for other stuff.
Gas kettle will boil quicker than 6/8 min.
Mike.

thanks mike, yes it would be better/easier to use gas, we did want a back up if it was needed in case we run out of bottled gas or was having difficulty finding a supplier wherever we are at that time, i know other motorhomers can survive without using gas,i just cant quite grasp it as yet,

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