Last time I'll ask this ;-)

[Insider]

OK - I've asked this question before but now going to have a bit more maths. I promise I won't ask again as next time hopefully I'll have Lithium!! Also the Renogy 2000w inverter is slightly reduced now on Amazon

So I have 2x90Ahr Lead Acid batteries with a Sterling 60A B2B(Overkill I know but solar means it's rarely doing much).

Almost everything I do is 12V and low wattage except for wanting to make porridge for the missus hence the question

I've measured the 800W microwave at 1280W when in use. Therefore I am going to be drawing at least 106A when in use and likely a bit more due to inverter inefficiency. However I only need to run the microwave for 2 mins a day. That's 3.5Ahr so overall very little but at an enormous current.

Using the C5 rule my batteries are only good for 36A which leaves a shortfall of 70A. My 60A B2B should supply about 50A??????

So will it work and if so is it very bad or just a little bit bad to start the van, leave it run for 2mins for the Sterling to kick in and then run the microwave for 2 mins. More worried about the batteries than the van as I would be tending to move most days when holidaying.

 

[SeanF1]

Can only give you my experience. We run a Nespresso machine which has a stated 1250w draw. Run it quite hard, ie each coffee is two pods and we often make 4 to 5 coffees in an average morning. So the machine runs for maybe 5 mins twice with a gap in between 5 min uses.
We have 2×110ah agm batteries and they cope without any problem. 300w solar on the roof generally has them back to 100% by late morning, given reasonable brightness.

 

[andykim]

Use a saucepan on the gas

 

[MisterB]

Stop faffing about and get that lithium battery you're dreaming of ....

We're just on our fourth day off grid, using the electric kettle and microwave (though not at the same time) whenever we wanted, and TV, lights, pump etc as per normal. we've driven a couple of hours each day and our solar isn't working too well - if at all, but that's because I messed about with the wiring.

We don't have B2B but have a Fogstar 300ah lithium. We are now down to 75% capacity and I expect that to go up to around 85% by the time we get to our next destination. This lithium lark has been a real benefit BUT costly, but peace of mind and the ability to just flick a switch WHENEVER we want to makes motorhoming so much more like motoring around in our own home !

 

[Insider]

Stop faffing about and get that lithium battery you're dreaming of ....

We're just on our fourth day off grid, using the electric kettle and microwave (though not at the same time) whenever we wanted, and TV, lights, pump etc as per normal. we've driven a couple of hours each day and our solar isn't working too well - if at all, but that's because I messed about with the wiring.

We don't have B2B but have a Fogstar 300ah lithium. We are now down to 75% capacity and I expect that to go up to around 85% by the time we get to our next destination. This lithium lark has been a real benefit BUT costly, but peace of mind and the ability to just flick a switch WHENEVER we want to makes motorhoming so much more like motoring around in our own home !

200Ahr lithium coming in around €1400 here at the moment. Would also come with a divorce!! Very happy with my set up with the only thing lacking running the microwave for a short period. Lithium is happening in 3 years when usage of the camper increases hopefully so for now the first part of the investment will be a good inverter. Hopefully my experience will be like SeanF1.

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[Raul]

I personally would not try to draw so much if batteries are a priority. No matter how you swing it, it does not add up. A 5mins idle with 50A load on alternator, will eventually take it’s tall. The alternator will not have enough cooling. The batteries will sag, and ask for more amps. Reduce the load, find a alternative to do the task, or increase charging power, as in solar. That will help when solar is active at least. Or, add more capable battery to give you the peak power you need. It’s allot to ask from 180A lead, and a 50A from a idle alternator.

 

[tezza-alli]

If you have later van with DPF its going to clog up(Removed mine and cleaned it, garage bill would have been £2k just for the DPF alone). With experience you'll kill the batteries. I've learnt the hard way and thats been with 3x 90Ah Gel Exides originally and then 3x 140Ah lead . Use your gas or buy lithium batteries is my advise.

 

[MisterB]

We are now down to 75% capacity and I expect that to go up to around 85% by the time we get to our next destination.

2 hour drive has boosted battery to 82%. I am happy with that and will sort out the solar when we get to our static. With solar I reckon we would be closer to 90% and with a decent B2B I reckon we would be fully charged or pretty damn close to it, so you can see the benefit of B2B if we were parked up for a few days and only drive for an hour or so in between stopovers and were heavy users.

PS the above isn't trying to tell people what or what not to do, just trying to give some 'real life' experiences to help people make an informed decision.

 

[Insider]

I have B2B and currently have 90W solar with another 90W going on when the weather is better. No issue with getting power back in and 3.5AHr is not much to have to replace but it's the rate of discharge that I'm worried about. First world problem really though isn't it. I think saucepan on the gas it is until I'm using the UK for landbridge next time. Thanks to all.

 

[Aucheorn]

I have 4 100w solar panels. 1500 w inverter (very poor output). I use 12v 120w immersion for hot water 5 ltr tank. 2x LA 110 ah batteries. The battery voltage has never gone below 9.6v on a dull winters day.
It seems to me that the more solar the better.

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[Insider]

I have 4 100w solar panels. 1500 w inverter (very poor output). I use 12v 120w immersion for hot water 5 ltr tank. 2x LA 110 ah batteries. The battery voltage has never gone below 9.6v on a dull winters day.
It seems to me that the more solar the better.

Agreed - just running out of roof space!!

 

[headlight]

I have 4 100w solar panels. 1500 w inverter (very poor output). I use 12v 120w immersion for hot water 5 ltr tank. 2x LA 110 ah batteries. The battery voltage has never gone below 9.6v on a dull winters day.
It seems to me that the more solar the better.

Battery voltage of 9.6v on lead acids ?
Have I read that right ?

 

[stevewagner]

200Ahr lithium coming in around €1400 here at the moment. Would also come with a divorce!! Very happy with my set up with the only thing lacking running the microwave for a short period. Lithium is happening in 3 years when usage of the camper increases hopefully so for now the first part of the investment will be a good inverter. Hopefully my experience will be like SeanF1.

Import lithium batteries from China @ 300$ for a 100amp lithium with BMS and Bluetooth