Victron solar data

[Sportzfann]

Yea that’s the “magic” of the mppt’s. If you had a cheaper older pwm solar charge controller it just puts the amps into the battery- so a 40-45a pwm would be the right size.

But the mppt’s convert the excess voltage to amps and put it all into battery at the proper voltage.

Remember it may be cheaper for you to split your solar array from 2S2P into two arrays of 2S (or maybe 2p - need the exact specs of the panels to know if that’s better), run another set of cables down from the roof and just buy another 150/45. Versus buying a 150/70 or 80 and trying to sell the 150/45 - it may be cheaper but more work running the cables. Just changing out to the 150/70 or 80 will be a lot easier. Remember you will need to increase the size of the wires from the mppt to the bus bar/battery.

Good Luck!

I ran 8/2 to the roof inside a 3/4” flex i can add another pair if needed, but like the one controller idea rather than two.
I will look at the 150/70 or 80. Would going to an all parallel setup be any better? I don’t really have room to add panels but want as much as I can get out of what I have. I might get the tilt brackets at some point to get some more watts during the winter months, I hoped to have enough PV to charge back to 100% in a day. I am using about 50 to 100 watts consistently to run things from my batteries while boondocking. Add the appliances to that number, microwave, etc. I didn’t really think about how the controller would take the additional volts and convert to more amps, so like I said a learning curve for me…. Thanks for all the replies!

 

[Rocketman]

Unfortunately, I can’t read the label - so small for my eye as is - and I can’t read it when I enlarged it:

Just post the:
Voc
Vmp
Imp

 

[Sportzfann]

Unfortunately, I can’t read the label - so small for my eye as is - and I can’t read it when I enlarged it:

Just post the:
Voc
Vmp
Imp

Let me try again
Jinko mod# jKM 325M-60HBL
Voc 41.1
Vmp 33.6
Imp 9.68
Isc 10.20

 

[GXMnow]

I would not parallel the panels. The higher voltage of 2 panels in series reduces the current in half and cuts the loss by 75% with the same wire size. My low buck DC system is using cheap "12 volt" panels from Amazon. Their VOC is 22 volts. I am running 5 in series which comes up to 110 volts VOC and works great on the 150 volt charge controller. For my 2,000 watts of panels, it works out to 90 volts at 22 amps for the whole array. Even at 22 amps, I run 2 pairs of #10 from the roof to the shut off switch, then it is just 10 more feet of #10 to the charge controller. But since the charge controller steps up the current to up to 35 amps, I then run 10 feet of #8 to the battery bank. I think I will change it to #4 though, I am losing over 0.15 volts in that run.

If you are going to buy a new larger controller, get one with more capacity than you need. That way you can add more later if you think you will need it. If you want to get the most possible out of the panels you have, you already need a 100 amp controller. The problem here is the price is not linear, they get expensive fast. The 150/100 is going for $516.80 on Amazon right now. Ouch. The second 150/45 is a much better deal. It's going for $218.45 Two of them get's you to 90 amps or 90 amps x 13.8 volts = 1,242 watts. That should be enough tp not clip in any normal conditions. That is 96% of the STC rating, so you would need perfect conditions to hit that.

How cold does it get where you are?

With the VOC at 41.1 volts, 2 in series is 82.2 volts x 1.2 = 98.64 volts. You could get away with the 100 volt charge controller and save a bit of cash. Too bad it looks like the largest 100 volt unit is only 50 amps, so you still need 2 of them. But they are just $164 on Amazon now.

 

[Sportzfann]

I would not parallel the panels. The higher voltage of 2 panels in series reduces the current in half and cuts the loss by 75% with the same wire size. My low buck DC system is using cheap "12 volt" panels from Amazon. Their VOC is 22 volts. I am running 5 in series which comes up to 110 volts VOC and works great on the 150 volt charge controller. For my 2,000 watts of panels, it works out to 90 volts at 22 amps for the whole array. Even at 22 amps, I run 2 pairs of #10 from the roof to the shut off switch, then it is just 10 more feet of #10 to the charge controller. But since the charge controller steps up the current to up to 35 amps, I then run 10 feet of #8 to the battery bank. I think I will change it to #4 though, I am losing over 0.15 volts in that run.

If you are going to buy a new larger controller, get one with more capacity than you need. That way you can add more later if you think you will need it. If you want to get the most possible out of the panels you have, you already need a 100 amp controller. The problem here is the price is not linear, they get expensive fast. The 150/100 is going for $516.80 on Amazon right now. Ouch. The second 150/45 is a much better deal. It's going for $218.45 Two of them get's you to 90 amps or 90 amps x 13.8 volts = 1,242 watts. That should be enough tp not clip in any normal conditions. That is 96% of the STC rating, so you would need perfect conditions to hit that.

How cold does it get where you are?

With the VOC at 41.1 volts, 2 in series is 82.2 volts x 1.2 = 98.64 volts. You could get away with the 100 volt charge controller and save a bit of cash. Too bad it looks like the largest 100 volt unit is only 50 amps, so you still need 2 of them. But they are just $164 on Amazon now.

It doesn’t get much below freezing where I live, I plan to be down south near AZ in the winter. I built an insulated battery box for my batteries and they havent gotten to freezing levels. I have a tank heater ready to install but didn’t see the need just yet.
the 150/45 controller is probably what I would install, then I would get a buss bar for neg and pos to tie the two controllers together before the batter. Plus the price is cheaper than trying to buy the larger model 150/100 I already have the one controller. Thanks,

 

[Rocketman]

Here are the issues: (with each option)

4p - you will have V=33.6 A=38.72. Most 4p combiners are only rated for 30amps, also you will be maxing out your 8awg wire - likely have voltage drop from that.

4s - Voc would require a 250 volt mppt - like 250/80. Costs more and not as good on RV’s.

2s2p - V=67.2 A= 19.36. This is a great spot for your setup with a 150/80.

2p into two 150/45 V=33.6 A= 19.72 into a mppt 150/45 (then repeat for the second set of panels). This one is most ideal from a solar perspective- your voltage is over 2x your battery voltage and all panels are in parallel. And you will never be clipped. The cons are you have to run an extra set of 10awg or 8awg wires. Victron handles two (or even many more) Solar charge controller just fine.

You could do one in 2s and the other in 2p and see which produces more power more consistently - then choose the best one after a while - after you post your results here.

My opinion… (worth only 2 pesos (because I am in my RV in Baja right now), if no issues getting the wires from the roof, and mounting the additional mppt - I would go with the second 150/45. Reasons - cheaper. Harvest all watts - no clipping). Second choice is 2s2p into a 150/80 (or 70).

PS you could use a 100/50 instead of the 150/45. No issues if 2p - if 2s figure out the low temp you could go. (It’s probably lower than you will be in - but you would want to know it - and post it on the mppt. -no issue having one 150/45 and one 100/50.


Good Luck

 

[Sportzfann]

Amazon Victron 150/45 $218
8 Gauge Marine Wire,30ft 8 AWG Duplex Marine Grade…$68.99
the wire run is easy, I have 3/4” conduit to the roof jbox and into where the batteries sit.
i would like to squeeze more charging out of my panels if possible, so I won’t have to run my generator.
so 2 panels parallel to each controller is the way. I already have an extra red and black bussbar with the 4x5/16 studs one more disconnect
This solar stuff can get pricey.

 

[Rocketman]

You might be able to save a few bucks with 10awg from the panels to the mppt - then #6 (or maybe #8 - just going off memory ???) from the mppt to the bus bar.

From the panels to the mppt will only be 20amps in the wire - so #10 will be plenty- #10 can handle 30 amps.