Inverter question

Trevorh13

New Member
Joined
Sep 25, 2019
Hi,

I have bought a new 2kw inverter for my self build camper and connected it to 2x 110ah batteries running in parrallel. The batteries were second hand but hold a charge ok and run all 12v systems without issue. However to run anything of the inverter that draws any kind of current (e.g 600w camping kettle) and the voltage detected at the inverter 12v supply side drops to about 11v. Shortly after the inverter turns off due to "low input voltage". I'm suspecting the batteries are dud and have bad cells or some such but want to verify my cabling isnt to blame. I tried to save myself a bit of money by running 2x 200a jump lead cables between the batteries and from the batteries to the inverter. Using ohms law I figure that to run the inverter at 2KW a supply current of 166.67A will be produced. Therefore my cabling should more than meet the demand.

As I say I suspect the batteries are handle the high draw rate but dont want to buy new batteries only to find I have the same problem.

Any advice would be greatly received.
 

Roadrunner

Active Member
Joined
May 29, 2016
Location
Glengormley
I dont like to say but a inverter to boil a kettle is nuts,gas for that is for that, inverters use to much current and yes it can be done with a lot of batterys but i would give it a mis.
To get van reclassed as a camper a two ring cooker is required unless the rules have been relaxed,some use a m/wave but again very hard on batteries.
Did you let them rest after using inverter and did they cum up again.
 

Trevorh13

New Member
Joined
Sep 25, 2019
Hi,

Yep we have a two ring gas hob and a low watt microwave too. It was a rekit out so the van was classed as a camper before hand. As soon as inverter switches off the battery goes back up to a little over 12v.
 

mistericeman

Active Member
Joined
Aug 3, 2016
I'd suspect batteries....
We have a 3000w inverter to power a kettle/toaster/microwave /slow cooker etc from our 3 x 100ah leisure batteries....
Running the microwave results in the inverter pulling 80 amps or so out of the batteries....
So the batteries need to be in top form.
 

Roadrunner

Active Member
Joined
May 29, 2016
Location
Glengormley
I'd suspect batteries....
We have a 3000w inverter to power a kettle/toaster/microwave /slow cooker etc from our 3 x 100ah leisure batteries....
Running the microwave results in the inverter pulling 80 amps or so out of the batteries....
So the batteries need to be in top form.
Would it not be better to have gas for kettles and heating water for washing up..
 

artobm

New Member
Joined
Oct 12, 2019
If you do decide to repace battery/batteries don't just replace one as even if one is new it will be dragged down to performance of older battery.
 

Trevorh13

New Member
Joined
Sep 25, 2019
Hi all thanks for advice and comments. I will try fitting two new batteries in the spring and see how I get on. Fingers crossed will solve the problem.
 

Den

New Member
Joined
Oct 18, 2019
I tried to "test" run a small fridge from my 2000w inverter using jump leads and the voltage drop was significant and failed... Using short "proper" cables from the battery to the inverter solved the problem. The leads make a bigger difference than you might think!
 
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