Solar help

[Wilkymelvin2024]

Hi All
I have a question i have a motorhome in the uk and it has all the electrics 12v and 230v, my question is i have purchased a renogy 50a dc to dc charger and as well as a invertor 2000w can i just remove the cable from my motor battery that goes to my leisuire battery and connect or do i need to run another one to charge my battery from solar ? and can i just remove the hook up cable that connects to the 240v fuse and connect that to the invertor.

I hope this makes sense

 

[stevewagner]

It's not normal for the cab battery and habitation battery to be connected like that. The DC to DC charger input should come from the cab battery with the output connecting to your leisure battery. You will also need to disconnect the battery charge relay. Make sure the cables are correctly sized and fused accordingly. If you look on the 12volt planet website they have charts to assist.
Does the inverter you bought have an automatic changeover switch built in?

 

[autorouter]

i have purchased a renogy 50a dc to dc charger and as well as a invertor 2000w can i just remove the cable from my motor battery that goes to my leisuire battery and connect or do i need to run another one to charge my battery from solar ?

First thing to say is, you need to clarify this. There should be no permanent wired connection between the starter battery and the leisure battery.

There is very likely an existing wire from the starter battery to a 'split charge relay', and another wire from the split charge relay to the leisure battery. This connects the two batteries together when the engine is running, which allows the alternator to charge both batteries. It disconnects to separate the two batteries when the engine stops.

If you install a Renogy 50A B2B, this will provide a correctly profiled charging supply to the leisure battery. Its input is connected to the starter battery, but its power comes from the alternator when the engine is running. The alternator charges the starter battery, and provides power to the B2B to charge the leisure battery.

The B2B is an alternative charging method to the split charge relay. If you install a B2B, you need to somehow disable the split charge relay, otherwise it will short-circuit the B2B input and output, which prevents the B2B from doing its job.

Once you have installed the Renogy 50A B2B between the alternator/starter battery and the leisure battery, you can connect a solar panel to the B2B MPPT solar input. But you don't need any extra connection to the leisure battery. The solar MPPT output to the leisure battery goes along the same wire you just installed.

 

[autorouter]

and can i just remove the hook up cable that connects to the 240v fuse and connect that to the invertor.

Yes you can in theory, but in practice you shouldn't. The motorhome mains inlet connects to everything 240V in the motorhome. That unfortunately includes the 240V mains charger that charges the leisure battery. So the inverter is supplying power to the motorhome, including the mains charger, which is charging the leisure battery, which is supplying the inverter - a circular route that is obviously a bad idea.. However if you switch off the mains charger, that problem doesn't happen.

Another gotcha is the 3-way fridge, the type that runs on gas, 240V and 12V. If you connect an inverter, the fridge auto-senses that a 240V mains connection is present,and switches from gas to 240V. Unfortunately it draws a lot of amps from the battery, and can easily flatten a full battery in a few hours. So you wake up to the next morning to a flat battery. You have to remember to switch the fridge to gas manually.

But apart from those two problems, most other things are OK to run on an inverter. But it's so easy to forget to switch things manually that most people have a separate input for the inverter, and a manual or automatic changeover switch that cuts out the charger and fridge. In fact some inverters come with an automatic transfer switch built in.

 

[Wilkymelvin2024]

Yes it does have a auto switch over. What I mean is disconnect the one from the motor battery to leisure battery then put a new one in to the leisure battery

Yes you can in theory, but in practice you shouldn't. The motorhome mains inlet connects to everything 240V in the motorhome. That unfortunately includes the 240V mains charger that charges the leisure battery. So the inverter is supplying power to the motorhome, including the mains charger, which is charging the leisure battery, which is supplying the inverter - a circular route that is obviously a bad idea.. However if you switch off the mains charger, that problem doesn't happen.

Another gotcha is the 3-way fridge, the type that runs on gas, 240V and 12V. If you connect an inverter, the fridge auto-senses that a 240V mains connection is present,and switches from gas to 240V. Unfortunately it draws a lot of amps from the battery, and can easily flatten a full battery in a few hours. So you wake up to the next morning to a flat battery. You have to remember to switch the fridge to gas manually.

But apart from those two problems, most other things are OK to run on an inverter. But it's so easy to forget to switch things manually that most people have a separate input for the inverter, and a manual or automatic changeover switch that cuts out the charger and fridge. In fact some inverters come with an automatic transfer switch built in.

Thank you very much for the information.

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[headlight]

Hi All
I have a question i have a motorhome in the uk and it has all the electrics 12v and 230v, my question is i have purchased a renogy 50a dc to dc charger and as well as a invertor 2000w can i just remove the cable from my motor battery that goes to my leisuire battery and connect or do i need to run another one to charge my battery from solar ? and can i just remove the hook up cable that connects to the 240v fuse and connect that to the invertor.

I hope this makes sense

What leisure battery/batteries do you have to run your 2,000 watt inverter and what 240v appliances are you intending running off it ?