rookie doubts

[Tut1975]

I'm going for similar battery etc but will opt, I think, for the renogy all in 1 bat to bat charger + mppt. The 2 limitations are it is 25 amp for each power source and handles a max of 25 volts from the solar panels. It looks impressive though and will trickle charge your starting battery from solar if the leisure batteries are full.
Do 250amp BMS exist? I'm struggling to find a decent 140amp.

 

[Tut1975]

Renogy 12V 50A DC-DC On-Board Battery Charger with MPPT

Renogy DCC50S DC to DC charger with solar input is used for charging a solar battery. The solar power battery charger charges the leisure battery w/ solar power.

uk.renogy.com

 

[Dexron]

i talked to renogy but it can't hold my solar panel.
I have not seen Orion with bluetooth, if there is it is a good option.

 

[HRTKD]

The Orion models with "Smart" in the name have bluetooth.

Orion-Tr Smart DC-DC Charger Isolated

 

[ianganderton]

i talked to renogy but it can't hold my solar panel.
I have not seen Orion with bluetooth, if there is it is a good option.

I was looking at the combined MPPT and DC chargers from Renogy and Kisae but they wont do what I need them to do so I'm going with seperate solar charge controller and DC to DC charger. It actually works out cheaper and I get much faster charge rates

 

[Dexron]

well, I saw that if it has bluetooth function

 

[Dexron]

looking at the victron orion 12/12 30 that you recommend, I see that it is isolated and not isolated.
can you tell me the difference for my use.

 

[Dexron]

Do 250amp BMS exist? I'm struggling to find a decent 140amp.

the BMS is a Daly 250a common port, I bought it from aliexpress.

 

[Dzl]

looking at the victron orion 12/12 30 that you recommend, I see that it is isolated and not isolated.
can you tell me the difference for my use.

The isolated is used when you need to keep your vehicle electrical system, and 'house' battery system separate, and you will not be grounding your house battery system. The non-isolated will be used if both sides of your system are grounded.

 

[HRTKD]

The isolated is used when you need to keep your vehicle electrical system, and 'house' battery system separate, and you will not be grounding your house battery system. The non-isolated will be used if both sides of your system are grounded.

Thanks for that explanation. The Victron Wiring Unlimited document doesn't go into enough depth on this topic. At least not enough for me to understand what has to happen when I have two 12v systems in my trailer. In theory, the two systems aren't going to crossover. There is no logical connection between them. Neither side charges or draws from the other. However, the negative lead from the existing battery (Trojan dual 6v) on the tongue goes directly to the trailer frame. This system will be limited to providing 12v power to the generator, tongue jack and breakaway brake system. I'm thinking that the new/additional battery system (LiFePO4 12v) will also need to ground to the chassis. This side will power the interior lights, furnace, etc (everything else that the existing system won't).

Can you suggest a source that provides more information? I would like to get a better understanding of the isolation issues.

 

[Dzl]

Can you suggest a source that provides more information? I would like to get a better understanding of the isolation issues.

Its hard to find good information on this, Victron, in my opinion, has done a very poor job of articulating the distinction in their documentation. They don't really address it directly.

I've pieced together bits and pieces of information here and there, and only have a very partial understanding.

You can see the beginnings of my inquiry and thought process here and some additional related info here

 

[HRTKD]

I read those threads a while back and just reread them. They make a little more sense to me. They also worry me. The question I end up asking myself is, "Should I be isolating my two systems?" They're both 12v and all they'll share in common is the negative ground. Since I don't plan to charge/draw between the two, I don't think I need to worry about it.

 

[Dzl]

I read those threads a while back and just reread them. They make a little more sense to me. They also worry me. The question I end up asking myself is, "Should I be isolating my two systems?" They're both 12v and all they'll share in common is the negative ground. Since I don't plan to charge/draw between the two, I don't think I need to worry about it.

The vague impression I have is that isolating the two sides of the system is not the default, and not necessary unless you have sensitive electronics (which might be more common in the marine world).

Also, if you did have sensitive electronics, you could use a DC-DC converter that is regulated and isolated for those circuits specifically.

But honestly, I still don't deeply understand the implications of one method or another.

 

[HRTKD]

But honestly, I still don't deeply understand the implications of one method or another.

I'm glad I'm not the only one. I suspect that trying to fully isolate the two systems could be difficult. However, isolating the generator, brake and jack "system" should be far easier than everything else.

 

[Dexron]

The isolated is used when you need to keep your vehicle electrical system, and 'house' battery system separate, and you will not be grounding your house battery system. The non-isolated will be used if both sides of your system are grounded.

then for the installation of my van without grounding I must mount the insulated one.
Is that so?

 

[Dzl]

then for the installation of my van without grounding I must mount the insulated one.
Is that so?

Grounding includes connecting the battery negative to the van frame or chassis. Is this something you will do?

 

[Dexron]

no, the negative connection goes to the auxiliary battery, to a terminal connected to the bms.

 

[ianganderton]

I think there is a problem with the same terms being used for completely different things in low voltage dc systems and mains/grid voltage AC systems. The problem is in vans and other off grid vehicles we are mixing the 2 electrical types and therefore the terminology doesnt work

Grounding in a low voltage dc enviroment (below 48V) is a way of saving on wiring. It allows the metal vehicle shell to be used as the return wire so saving 50% on wiring and complexity. It does cause plenty of problems in modern vehicles where the connections between differnet body panels might not be as conductive as first might appear. Add moisture into the mix and you end up with weird flashing lights on trailers.

Grounding in a mains/grid 240V or similar system is literally running a cable to the ground and is used to prevent device electrical problems killing people. In a house/grid/mains environment any device/appliance that has a metal outer should be grounded. The aim of this is if an appliance is damaged in some way and internal wires are connected to the outer shell the ground provides a short circuit route for the electricity to blow the fuse or trip the breakers so rendering things safe

So actually completely the opposite aims. This is because dc voltages below 48V are relatively safe and mains/grid AC voltages are deadly

I haven't looked at the specs but I'd hazard a guess that 240V/110V victron products designed for in-vehicle use and therefore impossible to ground unless mains connected are insulated differently from those designed for an environment where a ground to earth connection can be made

Hope this is what you guys were talking about and helps

 

[Dexron]

I get it.
the installation of the van, lights, water pump, usb sockets and heating go to 12v.
the induction hob, the hot water boiler and the refrigerator are connected to the inverter at 220v.
The inverter is only connected to the bsm output and battery positive.
for this installation I do not think a ground connection is necessary and I would need an isolated Orion charger.
I don't know if I'm wrong about something.

 

[ianganderton]

For what you are planning with a priority on both Ac power and shore power charging I would go for one of the charger inverter units. They combine all the AC power very neatly including transfer switch (when you plug your van into a mains plug say at a campsite the unit will automatically switch from batter inverter power to shore/mains power) and charge the house battery

with a house battery as big as you are planning there is no point in alternator charging. Just won’t be enough

in the UK and Europe there are ooddles of campsites with electric mains hookups. easy to pop to one for a night to refresh your batteries.