Wiring size mistake?

[RV8R]

Hi guys

So I sprung for the purchase of a Victron 100/50 MPPT. I have gotten no charging out of it so far as it has been pretty cloudy. Even then, my old Chinese MPPT would have charged even a little bit.

Reading through the Victron manual it states that charging will not commence unless the PV voltage is 5v higher than the battery voltage! That means my panels need to put out over 18v for my lithium batteries to charge? Seems a bit ridiculous. My panels only have an open circuit voltage of and 23v maximum. Looks like I have no choice but to rewire my panels in series instead of parallel for it to work?

I have 2 of those Victrons 100 | 50

I really like them.

The software allows you to turn on & off the charger.

Yes 5 volts over battery voltage, but not an issue on my 12vdc & 60volt solar array.

3S2P gets my array roughly 60 volts @ 10 amps. In the spring, the system voltage is close to 50 volts @ Dawn ?.

What are your panels ? ,,, If you can series them it will probably be better for you to get you well above that 5 volt mark.




6am top left corner in May 24 - 48volts ?;

 

[Rocketman]

Or go like 2s2p - if you have 4 panels. I like that setup - advantages both ways.

 

[RV8R]

Or go like 2s2p - if you have 4 panels. I like that setup - advantages both ways.

exactly ,,, I have 6 - 100W panels so 3S (2P) is about as high as I can series them.

4S is going to get me too close for my comfort to a possible over volt issue

 

[Sugarkryptonite]

Thanks guys but I only have 3 panels on my van so I can’t do a series parallel array

 

[RV8R]

Thanks guys but I only have 3 panels on my van so I can’t do a series parallel array

Hi @Sugarkryptonite

I missed the 3rd panel, but see now it was added.

So, if you have a rough wiring schematic it would help your cause here to post it, as all the verbiage gets lost where a schematic is very visually helpful.

I guess If it were me, I might change controllers to something like a Victron 100 | 50 that can easily take the 3 panels in series.

 

[Sugarkryptonite]

Hi @Sugarkryptonite

I missed the 3rd panel, but see now it was added.

So, if you have a rough wiring schematic it would help your cause here to post it, as all the verbiage gets lost where a schematic is very visually helpful.

I guess If it were me, I might change controllers to something like a Victron 100 | 50 that can easily take the 3 panels in series.

Hi there. Actually the Victron 100/50 is exactly what I bought. I was trying to avoid going series that’s why I bought the more expensive Victron for it’s higher current but I guess that didn’t work out because of their 5v minimum limit with the panels I’m using

 

[RV8R]

Hi there. Actually the Victron 100/50 is exactly what I bought. I was trying to avoid going series that’s why I bought the more expensive Victron for it’s higher current but I guess that didn’t work out because of their 5v minimum limit with the panels I’m using

I missed that you purchased a 100 | 50. I speed read a lot of these threads, but if I understand you have 3 - 200W panels;



So If You are “3S” then you are roughly 60 volts @ 10 amps ?

So I have the same Victron @ my Cabin with 6 - 100W (3S2P) so roughly 60 volts @ 10 amps.

Same / Same


It has worked out very good for me @Sugarkryptonite & another thing I will note might be irrelevant for You ?‍; That Victron can handle on 24vdc batteries 1400W Array.



All You gotta do is go “Series” on your 3 panels !!


Also, I turn the charging on & off with my iPhone ,,, Not sure how familiar you are with the software & setup, but IIRC you can do everything over Bluetooth on your handheld device ,,, there is a “On / Off” setting.

 

[Sugarkryptonite]

I missed that you purchased a 100 | 50. I speed read a lot of these threads, but if I understand you have 3 - 200W panels;

View attachment 187260

So If You are “3S” then you are roughly 60 volts @ 10 amps ?

So I have the same Victron @ my Cabin with 6 - 100W (3S2P) so roughly 60 volts @ 10 amps.

Same / Same


It has worked out very good for me @Sugarkryptonite & another thing I will note might be irrelevant for You ?‍; That Victron can handle on 24vdc batteries 1400W Array.



All You gotta do is go “Series” on your 3 panels !!


Also, I turn the charging on & off with my iPhone ,,, Not sure how familiar you are with the software & setup, but IIRC you can do everything over Bluetooth on your handheld device ,,, there is a “On / Off” setting.

Yup thanks! Just from what I read it’s less efficient if a single panel gets some shade wiring in series but oh well I’ll deal with it for now

 

[RV8R]

Yup thanks! Just from what I read it’s less efficient if a single panel gets some shade wiring in series but oh well I’ll deal with it for now

Ya ,,, I have heard that as well, & I guess I would say try it & see.

It is easy to dwell on efficiency theory & attempt to eek out the last watt you can from the Sun, but from my experience with my Array ,,, I might get better efficiency with parallel & I think it is irrelevant if it is a crappy weather day. And if it is a good weather day it doesn’t matter.

Just try it & see how it goes - Good Luck !!