Thank you very much for your helpful reply . On my other van I have 2 batteries and a 1000 w inverter and it does boil the 600w kettle but does start to beep, so I think my problem is a/ The battery ,I am booked in to have another one fitted on Monday. Can't do it myself as there is only space for one on this Escape. and b/ I need to upgrade my inverter from 1000 to 15000 . Fingers crossed then xJust a few comments ref your setup (other ones already made on the thread, but worth recapping)
200Ah of Batteries - can you use with an inverter? Yes, for a short period. With a Battery Bank that size, you should be able to use a kettle without a problem. If you got say a 800W Travel Kettle, you would be drawing around 80A from the battery while running. Kettle that size with 2 mugs worth of water will take upto 6 minutes to boil, taking out around 8Ah from the battery - well within the usable capacity of the battery.
Whether that is a good use of battery power rather than using a gas hob is a decision only you can make, not others (FWIW, I use battery power to boil a kettle and run a microwave, as well as heating my shower water, so I am certainly not saying it is automatically a bad idea).
So why are you not able to do it? two possibilities....
1) Batteries have had it. That would explain it. You would also see a drop in the voltage in general use. How long do the batteries last generally in day to day non-inverter use?
2) Cabling from Battery to Inverter inadequate. If the cable is too light, you will get a large voltage drop and the inverter will complain as you see.
What size cables have you and how long are they. Check the voltage at the battery terminals before you put the kettle and and keep monitoring as the kettle switches on and the inverter starts to beep - what is the voltage just before the beeping starts?
An interesting read is this book from Victron - https://www.victronenergy.com/upload/documents/Book-Energy-Unlimited-EN.pdf
It is useful to read generally, and section 6.6 covers a real life analysis of power use when cooking an entire meal via Battery Power.
Thank youvery much for your helpful reply xFirst thing i'd check is the power requirements of the kettle. If its exceeding the output of the inverter that will cause an alarm. Next i'd check size of the cables from battery to inverter. Volt drop is a real problem on 12v(power being used to warm cables), particularly at higher currents, you may find even though volts are high leaving battery, they arrive low enough at inverter to cause a low voltage trip. I run a similar rig with 1400w draw microwave and need at least 25mm tails and feeds from split charge main alternator to carry the 116 amp (1400/12) required, and thats splitting the power from main , aux batts & alternator & solar input, and assuming I can keep voltage from dipping below 12v. Also most pure leisure batteries are not designed to supply high currents, they have higher internal resistances therefore also suffer from volt drop. Check voltage at inverter input when under load. I get over this by always running the engine when microwave is on. Be real careful with running such high loads, the currents at 12v are so massive , fire is a real risk due to stuff melting. Make sure all cables and accessories are properly specced for the current and everything is super tight, appropriately fused and regularly inspected for overheating. If in any doubt about cable design consult a decent electrical engineer. Refillable gas bottle might be the way forward, or as others suggested a far lower powered kettle. Or even a twig stove/kelly kettle for emergencies. More batteries would also combat the leisure battery internal resistance issue but gets heavy & expensive. Hybrid batteries could help if not already fitted
Can I ask which 500W portable induction hob you have?If you are not fitted with a pace-maker, then I would suggest you also consider an Induction Hob rather than a kettle.
You will be able to boil a kettle of water on an induction hob as fast as with a kettle of the same power. A stove-top kettle that works on an induction hob will work on a gas hob just as well (I use the same collapsible kettle on both), and you will also have a device that givess you much more flexibility.
I actually carry a pair of 500W Portable ones and can take them outside to use under the awning as well as inside the Motorhome.
Something to be aware of though ... almost all induction hobs work by cycling through full power and off to average the power selected. so if you get a 1000W hob and set it to 500W, you will still need an inverter capable of delivering 1000W. (my 500W ones are a maximum of 500W)
I have 4 x 110amp leisure batteries connected to a 5kW/Hr inverter. My system is overkill, even for wild camping.