What size of Charge Controller

[Canadian Eh]

I want to replace the Zamp solar controller with a Victron MPPT but unsure of which model to get. I contacted Victron and they sent me a link to a calculator which might as well be written in Chinese.
System is 2X170 solar panels wired in series and 4X100 Lithium batteries.
Thanks,

[mowog73]

I installed a Victron 100/30 smart solar MMPT with built in bluetooth.

it supports 12 volt -24 volt batteries, with up to 100 volt solar input at 30 amps

It is limited to 400 watts total solar input, I have 2 200 watt panels.

This would work well for you, with 2 170 watt panels. If you were considering adding additional panels in the future, you might consider the 100/50 model.

It's good for up 600 watts solar. At that point you would have to ensure that your wiring is large enough gauge to support the higher amperage though.

I have experimented with running my 2 panels either series solar output on average is 50 volts at 9-11 amps, and wired parallel, 25 volts at around 15-20 amps, Both seem to charge equally efficiently, so I kept them series. Higher volts at lower amps doesn't tax the wire gauge as much.

[Rolland]

You might check out the educational videos on the AM Solar site. They have one going over Victrons MPPT controllers

[edc1911]

This.

Originally Posted by mowog73

I installed a Victron 100/30 smart solar MMPT with built in bluetooth.

[ppine]

YOu need 30 amps, but 40 would be better to allow some expansion later.

[Canadian Eh]

I have no room for expanding the solar so I went with the Victron 100/30

[Tabasco_Joe]

Originally Posted by Canadian Eh

I have no room for expanding the solar so I went with the Victron 100/30

Good choice.
And you have some room for expansion.

[kgriff5667]

You may need to expand your system with the 4 lithium batteries, so I would suggest a 40 amp controller. Because of the cost difference between the Victron and Renology controller, I went with the Renology with the blue tooth. Renology is running some great sales on their systems now.

[W5CRE]

Originally Posted by Canadian Eh

I have no room for expanding the solar so I went with the Victron 100/30

It appears you made a good choice. To expand your system you would be well served to go with portable or foldable panels and their own solar charge controller. You may need this to keep that large battery bank up.

[Papadave]

The first number on a victron controller is max input voltage the second is max amps output. Your panels in series are probably 20/24 volts each so 40/48v input. Running in series reduces the amperage so lighter wire can be used. I have the 150|85 on my rig with 4 100w panels in parallel running 2 100ah lipos through a 3000/6000w inverter.. I may go to six panels so I got the larger controller. With six panels I would probably go series parallel. 2 60v input legs. If your panels are higher input voltage than the controller can handle you can wire the panels parallel.

[Canadian Eh]

I appreciate all the replies. Our 24' C class has limited roof area and it was a stretch to get the two 170 W panels to fit. I could in theory add a couple of narrow 100 W panels but this would make it almost impossible to access anything on the roof. Carrying a folding panel would create a storage issue, just not that much space to keep it in the bus. My reasoning behind going with 4 batteries was to smooth out the capacity and usage by having enough backup. We don't use the microwave and I will run the genny if I need the AC. I have a Renology inverter and DC to DC converter. One bolt has fallen out of the inverter so I'm not that happy with their quality.

[Rolland]

Originally Posted by Canadian Eh

I appreciate all the replies. Our 24' C class has limited roof area and it was a stretch to get the two 170 W panels to fit. I could in theory add a couple of narrow 100 W panels but this would make it almost impossible to access anything on the roof. Carrying a folding panel would create a storage issue, just not that much space to keep it in the bus. My reasoning behind going with 4 batteries was to smooth out the capacity and usage by having enough backup. We don't use the microwave and I will run the genny if I need the AC. I have a Renology inverter and DC to DC converter. One bolt has fallen out of the inverter so I'm not that happy with their quality.

Sounds like a good plan. We have limited area on the roof so plan to increase it from the 100w now to 300w and use the factory wiring. Then if I need more due to shading in the site would either get a portable or charge with the Genny.

[W5CRE]

I would recommend you mount your 170watt panels on tilting brackets. Tilting the panels can give you an additional 16% output. This may be important for you depending on your daily usage. You do have a lot of battery for that size solar system. For 400ah of battery I would want 800watts of solar. This would, on average, recharge 200ah a day. Of course how well any solar system performs is highly dependent on the panels orientation to the sun, the weather and location, location, location. What is most important is to be able to replace your average daily usage. Your 340 watts will at best give you 96 amps of recharge per day and on a average good solar day about 83 amps. I would still recommend some portable panels and controller.

[W5CRE]

FYI calculator is https://pvwatts.nrel.gov/pvwatts.php
Set system size, remember it's in KW
Module type I set as premium
Array type as Fixed(roof mount)
System losses No Change
Tilt I varied from 0° to 40°, I found the best for Quartsite, Az to be around 30° for January
Azimuth 180°
The numbers I posted previously were for Quartsite, Az in January. For Calgary, Canada, well, all I can say is buy a generator.