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24V wiring diagram help

rolandbremb

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Jul 17, 2020
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Hi there!

currently planning out my electrical system, and would love to get some feedback on my wiring diagram... is this going to work out or will it blow up in my face? lol

van electrical.jpg
 
Hard (for me) to prove a negative - but nothing bad is jumping out. Couple of thoughts....
1) If you pull 200a @ 24v = 4800w from the battery bank (5kwh) it will be dead (100% DOD) in a hour.... maybe you don't plan on full load very often
2) You might want to add a shunt or at least some meters - so see what's happening. Those victron smart shunts that display to your phone seem pretty cool.

Good luck as you build your system :)
 
Hard (for me) to prove a negative - but nothing bad is jumping out. Couple of thoughts....
1) If you pull 200a @ 24v = 4800w from the battery bank (5kwh) it will be dead (100% DOD) in a hour.... maybe you don't plan on full load very often
2) You might want to add a shunt or at least some meters - so see what's happening. Those victron smart shunts that display to your phone seem pretty cool.

Good luck as you build your system :)
Thanks!

Yes, I have a 500A shunt I forgot to add to the diagram!

I don't think I'll ever max out this system... the biggest draw from the inverter would be my induction cook top with around 1800W, and I can plan to not use the AC at the same time.

One concern was around he wire size... do you think 2 AWG is enough? I've conflicting things about that, and was considering to upgrade to 2/0 AWG.
 
One concern was around he wire size... do you think 2 AWG is enough? I've conflicting things about that, and was considering to upgrade to 2/0 AWG.
I run 2/0 (fine-strand flexible welding cable) for 250amps capability and routinely run 150a with 200a spikes with no detectable warmth - total length maybe 8feet from battery to inverter. Just blind advice - 2/0 would be better in my opinion. However, 2 or 2/0, the real test is to make sure the wire doesn't get hot under max load.
 
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I run 2/0 (fine-strand flexible welding cable) for 250amps capability and routinely run 150a with 200a spikes with no detectable warmth - total length maybe 8feet from battery to inverter. Just blind advice - 2/0 would be better in my opinion. However, 2 or 2/0, the real test is to make sure the wire doesn't get hot under max load.
got it!

the inverter actually asks for a 2AWG in the manual so that should be fine there. I might upgrade to 2/0 for in between the batteries and to the bus bars.
 
Hi there!

currently planning out my electrical system, and would love to get some feedback on my wiring diagram... is this going to work out or will it blow up in my face? lol

View attachment 52338
It seems to me that you might want a way to remove power from the Positive Bus Bar as I do not know whether it is safe/desired to run the inverter directly from the output of the 12V to 24V DC-DC. The only cutoff is on the 200AH bank. There you show two 200AH batteries in parallel. Is this right as the total would be 400AH.
 
It seems to me that you might want a way to remove power from the Positive Bus Bar as I do not know whether it is safe/desired to run the inverter directly from the output of the 12V to 24V DC-DC. The only cutoff is on the 200AH bank. There you show two 200AH batteries in parallel. Is this right as the total would be 400AH.
I actually run the batteries in series, but I thought about the same. Thanks for pointing this out.

So I would have 2 terminal fuses on the battery, one for the bus bar and one for the inverter?
 
What are you using for the extra AC to DC 40a charger?

The GW will give you 60a also.

Add a disconnect from solar to GW unit.
thanks!

yes I also have a disconnect for the solar panels that I don't show.

the extra charger is actually not a charger... it's a 24v air conditioner!
 
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quick question regarding BMS... I have 2 200ah LifePo4 batteries that I'll connect in series with a 100a BMS each. Is the maximum discharge rate then 200a (100a BMS + 100a BMS) * 24V ~4800W? or am I limited to 100a *24V because each BMS can only handle 100a??

just want to make sure I'm not missing something.
 
quick question regarding BMS... I have 2 200ah LifePo4 batteries that I'll connect in series with a 100a BMS each. Is the maximum discharge rate then 200a (100a BMS + 100a BMS) * 24V ~4800W? or am I limited to 100a *24V because each BMS can only handle 100a??

just want to make sure I'm not missing something.
100 amps
 
Looks excellent. I want to do the same thing but I'm having a heck of a time finding a 12/24v DC/DC converter for the truck alternator circuit. Would you mind telling what you're using? Thanks
 
hmm... well I'll probably never use the max load anyway, and ~2400W is plenty
I understand what you want to do but unfortunately all current must pass thru both the BMS's in the series. If batteries are in parallel, each BMS can handle up to 100 amps.

But you must remember that 100a times 24V is 2400 watts, the same as running two 12V batteries in parallel with BMS's at 100a each, (1200 watts times 2).

Some BMS manufacturers do not recommend series connection, contact your battery manufacturer first.
 
Looks excellent. I want to do the same thing but I'm having a heck of a time finding a 12/24v DC/DC converter for the truck alternator circuit. Would you mind telling what you're using? Thanks
there's a couple options but I got the "Victron Energy Orion-Tr Smart 12/24-Volt"
 
I understand what you want to do but unfortunately all current must pass thru both the BMS's in the series. If batteries are in parallel, each BMS can handle up to 100 amps.

But you must remember that 100a times 24V is 2400 watts, the same as running two 12V batteries in parallel with BMS's at 100a each, (1200 watts times 2).

Some BMS manufacturers do not recommend series connection, contact your battery manufacturer first.
thanks!

yes I checked with them, and I can connect the batteries in series!
 
Sorry for coming to this thread late, but there's a lot of great info here! I'm designing my 24v system currently, and have a quick question about the above diagram.

In your second diagram you change the Growatt's positive input from its original connection on the Positive Bus Bar to connecting directly to your battery bank. Piecing things together, it looks like it was in response to @Jasgeer saying "you might want a way to remove power from the Positive Bus Bar as I do not know whether it is safe/desired to run the inverter directly from the output of the 12V to 24V DC-DC." Does connecting the inverter directly to the battery (presumably to a different terminal than the Positive Bus Bar ties into) correct this issue because the DC-DC's output runs into the battery before being "pulled out" by the inverter?
 
Looks excellent. I want to do the same thing but I'm having a heck of a time finding a 12/24v DC/DC converter for the truck alternator circuit. Would you mind telling what you're using? Thanks
Why not install a second alternator on your truck and use a 24VDC alternator regulator (mine is an adjustable regulator)? The normal 12V alternator will put out the nominal 24VDC without a problem (at least it did for me).
 
Is the 30 amp fuse on the line between the 24to12 DC converter and your main hot bus bar on the bus bar end or the converter end. Imagine a fault on that being fed by the battery (opposite the normal direction of the power flow). If that happened, you are relying on the 250Amp battery fuse protecting a 6awg wire. Just a thought.
 
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