I need help picking out a solar charge controller

[JaseyB]

Hey folks, so I have my panels delivered. I have picked out my battery and now I am looking to buy a charge controller to link all this together.

I have purchased 3 solar panels from Amazon for a total of 960W (spec has also been attached):

Solar Panel 310W Monocrystalline Silver Frame, Off Grid, On-Grid, High Efficiency 20% : Amazon.co.uk: Business, Industry & Science

Solar Panel 310W Monocrystalline Silver Frame, Off Grid, On-Grid, High Efficiency 20% : Amazon.co.uk: Business, Industry & Science

smile.amazon.co.uk

After some much appreciated help from you guys I have a battery picked out though I have not finalised the purchase yet so this might change depending on this thread.

Roamer 24-230SMART3 - 24V 230Ah LiFePO4 Lithium Leisure Battery + Free Consultation

Buy the Roamer 24-230SMART3 and get a FREE electrical system design consultation worth £120. The Roamer 24-230SMART3 is a high power 24V 230Ah LiFePO4 battery for install in a campervan, motorhome, boat or tiny house. Includes 250A continuous discharge, active balancing, Roamer BMS bluetooth...

roamerbatteries.com

So I now need to look out a charge controller for all of this.

From an earlier conversation @Rednecktek told me I need a 40A controller although this was slightly off-topic at the time so I didn't go into details on this.
The supplier of the battery recommends Victron product (as do a lot of the videos I see online) but there are just SOOOOooooo many. ??

Can you guys recommend one for me that will scale if I add any more batteries/components to my build? I dont think I'll have room for any more panels so that should be fairly fixed.

I do intend to use an inverter (probably around 2500-3000W) and a dc/dc charger to the mix and would like to have a access to control and monitor through the Bluetooth app or similar.

Thanks in advance for any and all help with this.

Jason

 

[chrisski]

I recommend a Victron 100/30 or Victron 100/50 based off my experiences. Honestly, at least a 30 amp MPPT.

My 30 amp Victron SCC on a 24 volt battery with 900 watts of portable panels will push 30 amps at the charging voltage, which for me commes out to 840 watts. On a separate controller, also a Victron 100/30, I have 1050 watts of flat panels on a flat roof and that can also max that SCC out at 840 watts, but for shorter amounts of time.

If your panels are flat, you are unlikely to reach the 960 watt potential very much.

It’s always better to go bigger. If you expect to be charging at max a lot perhaps a 100/50 would be better for a couple of reasons. Some people discourage these from running at max output. A second reason is if the SCC gets hot, it will throttle back the charge by 25% to 33%. Mine have only got hot when the SCC was in direct sunlight.

 

[12VoltInstalls]

Eith components scaling in is as easy as buying more than you need, or buying an additional controller.

1000W of panels is almost 80A at 13.2VDC
Start from there I’d say

 

[JaseyB]

I recommend a Victron 100/30 or Victron 100/50 based off my experiences. Honestly, at least a 30 amp MPPT.

My 30 amp Victron SCC on a 24 volt battery with 900 watts of portable panels will push 30 amps at the charging voltage, which for me commes out to 840 watts. On a separate controller, also a Victron 100/30, I have 1050 watts of flat panels on a flat roof and that can also max that SCC out at 840 watts, but for shorter amounts of time.

If your panels are flat, you are unlikely to reach the 960 watt potential very much.

It’s always better to go bigger. If you expect to be charging at max a lot perhaps a 100/50 would be better for a couple of reasons. Some people discourage these from running at max output. A second reason is if the SCC gets hot, it will throttle back the charge by 25% to 33%. Mine have only got hot when the SCC was in direct sunlight.

I have already been recommended a 40A controller. Is this a calculation that brings you to 30?
Is it better that I go bigger?

I would prefer to go with just the one controller if that's possible as I only have the one array of panels. I don't really see any need for more?
I am unsure yet how to arrange these 3 panels whether in parallel or series but I'll come to that later when I get the components together.

I also am getting quite confused with the numbering. There's a 100/30 and there's 150/30. What's this 100V and 150V and what should this mean to me? Again, is it better to go bigger or is it just a waste of money?
Surely someone really should just put together a "campervan solar in a box" type setup for us part-time noobs .

 

[JaseyB]

Eith components scaling in is as easy as buying more than you need, or buying an additional controller.

1000W of panels is almost 80A at 13.2VDC
Start from there I’d say

I've already got a 24V battery lined up. Does this not mean everything should be 24V?

 

[wiseacre]

100/30 ~ basically shorthand for ~ voltage limit input/amp output
use the panel's VOC to calculate voltage input

100/30 ~ 100v max input/30 amp charge output
100/50 ~ the difference is the charging amps go up to 50a

Based on your panel's specs you would need to wire the panels in parallel using a 100/50 SCC
41.54 VOC wired in series (3s) = 124.62v and would require a 150 model

to add to the confusion
wired in parallel the amp input would be close to 30a
in series it would be about 10

so basically
in parallel a 100/50 would be my choice
in series a 150/35 would be fine
Price for a Victron is about the same either way

wired in parallel you'll need some additional items, y connectors and a fuse for each panel

 

[rmaddy]

Use Victron's MPPT calculator. You can enter the specifics of your panels and play around with different layouts and it will recommend the best matching charge controller. The 150/35 would be a great choice for your panels in series.

MPPT Calculator - Victron Energy

MPPT Calculator - Victron Energy

www.victronenergy.com

 

[Browneye]

Victron FTW.
EPever runner-up.

 

[JaseyB]

Many thanks folks.
So I suppose the real question I should be asking here first is what is the best way to layout my panels?
Series sounds about the easiest. That's just a daisy chain right?

 

[rmaddy]

Series sounds about the easiest. That's just a daisy chain right?

Yep. Very simple. Just respect that you will be dealing with about 120VDC.

Series has a lot of benefits. Simpler install. No fuses needed. Lower amperage means smaller, cheaper wire. Better lower light performance. Just make sure all three panels in series are in the same plane and you don't have a lot of shading issues.

 

[JaseyB]

Yep. Very simple. Just respect that you will be dealing with about 120VDC.

Series has a lot of benefits. Simpler install. No fuses needed. Lower amperage means smaller, cheaper wire. Better lower light performance. Just make sure all three panels in series are in the same plane and you don't have a lot of shading issues.

Cool, thanks. I feel like this is starting to take shape
So back to the charge controller: The calculator wants to know my cable run length. I can just estimate this right?
It then asks for the cross-section. Should I be looking at my wiring before buying a charge controller? ?

 

[rmaddy]

The length and size of the wire helps calculate voltage drop. Definitely worry about that when you are getting ready to buy the wire but I wouldn't worry about that when deciding which SCC to buy.

Something to consider though. You seem to be buying one piece of equipment at a time and then asking about the next one. That's far from ideal. It could lead to components that don't play well together or don't meet your needs as well as they could. I suggest working out every detail of your electrical/solar system before buying anything else. Figure out every component, every wire, every fuse, etc. and triple check it all works correctly and will meet your needs. Work up a wiring schematic and post here for review. People can double-check your choice of wire sizes and fuse sizes and ensure everything plays well together. Then you can go and buy it all knowing that what you are getting is the right stuff the first time.

 

[cs1234]

@rmaddy

In case you weren't following his previous thread.. he is mounting his panels on a van, so his cable run is probably be going to be pretty short. I imagine he would just be using normal 10gauge pv cable.

@JaseyB
When getting a Victron MPPT charge controller, make sure to get the "SmartSolar" ones, not "BlueSolar".. they are the ones with built in bluetooth and ve.smart that makes coupling up with other ve.smart victron gear real easy from a wireless standpoint. The 150/35 would work for you, or if you think it's going to be a lot sunnier in England than it normally is and want to make sure you can capture every watt your panels would ever produce .. say you went to Spain or something.. the 150/45 would have plenty of headroom to never be maxed out.

 

[cs1234]

@JaseyB

Personally, I like the idea of keeping voltages running around low, and would just eat the small voltage loss and use three 100/15 .. one for each panel and one cable running from each panel to its own inverter. But I'm silly that way and love redundancy.

edit.. use the 75/15 for each panel.. bit cheaper and still well within the panel range.

edit again.. In a van, you might not want all that extra cable and the extra MPPTs all over though, so this whole post is likely tacky.

 

[JaseyB]

The length and size of the wire helps calculate voltage drop. Definitely worry about that when you are getting ready to buy the wire but I wouldn't worry about that when deciding which SCC to buy.

Something to consider though. You seem to be buying one piece of equipment at a time and then asking about the next one. That's far from ideal. It could lead to components that don't play well together or don't meet your needs as well as they could. I suggest working out every detail of your electrical/solar system before buying anything else. Figure out every component, every wire, every fuse, etc. and triple check it all works correctly and will meet your needs. Work up a wiring schematic and post here for review. People can double-check your choice of wire sizes and fuse sizes and ensure everything plays well together. Then you can go and buy it all knowing that what you are getting is the right stuff the first time.

The only way I can get my head around it is to follow the flow and fill in the blanks. as @cs1234 says i'm converting a van to live in so panels on the roof was the first place to start. At that stage I just bought the most output and put on as many as I could fit. Hence the 3 x 320W panels were purchased before they disappeared. This is the only item I actually have already.
As I followed the flow I was told that I need to know what system I was building (12V or 24V or even 48V) so I headed to the battery and with help from you guys arrived at the Roamer 24V 230Ah. This is in the basket until I finalise every else.

Cabling is there in the mix at the back of my mind right now and I will defo be taking advice on this as I feel it's easy to undersize and create dangers. I thought that this would all need to be arranged after the components until I went through the calculator.

@cs1234 I will be travelling in the UK until I know everything is working as expected but then I will be heading for the continent and following "Goldilocks" weather. North in the summer and south in the winter. Nothing too hot or too cold. That controller was one I was looking at earlier but I was getting a bit confused with all teh options and needed some sort of confirmation before I add to the basket.

 

[JaseyB]

@JaseyB

Personally, I like the idea of keeping voltages running around low, and would just eat the small voltage loss and use three 100/15 .. one for each panel and one cable running from each panel to its own inverter. But I'm silly that way and love redundancy.

edit.. use the 75/15 for each panel.. bit cheaper and still well within the panel range.

The only problem I see with this is that I will need to drill extra holes in my van and could lead to other problems with wire runs and weathering.
Also the extra room for the controllers is a problem when I'm struggling for space to put all this stuff

 

[12VoltInstalls]

I've already got a 24V battery lined up. Does this not mean everything should be 24V?

Yes.

 

[chrisski]

I have already been recommended a 40A controller. Is this a calculation that brings you to 30?
Is it better that I go bigger?

I would prefer to go with just the one controller if that's possible as I only have the one array of panels. I don't really see any need for more?
I am unsure yet how to arrange these 3 panels whether in parallel or series but I'll come to that later when I get the components together.

I also am getting quite confused with the numbering. There's a 100/30 and there's 150/30. What's this 100V and 150V and what should this mean to me? Again, is it better to go bigger or is it just a waste of money?
Surely someone really should just put together a "campervan solar in a box" type setup for us part-time noobs .

30 amps will be enough to swing by, and you may lose a couple hundred watts. 40 amps is better, but the Victron controller line I’m familiar with goes from 30 amps to 50 amps. Quite a price jump also. It’s all whether of not it’s worth the extra $100 to you.

The first number is the max volts. With the Victron line, the 100 volt controllers tend to do 12 or 24 volt charging. The 150 volt doesv12 volt, 24 volt, 36 volt, or 48 volt charging, but again quite a jump in price.

 

[73powerstroke]

Hey folks, so I have my panels delivered. I have picked out my battery and now I am looking to buy a charge controller to link all this together.

I have purchased 3 solar panels from Amazon for a total of 960W (spec has also been attached):

Solar Panel 310W Monocrystalline Silver Frame, Off Grid, On-Grid, High Efficiency 20% : Amazon.co.uk: Business, Industry & Science

Solar Panel 310W Monocrystalline Silver Frame, Off Grid, On-Grid, High Efficiency 20% : Amazon.co.uk: Business, Industry & Science

smile.amazon.co.uk

After some much appreciated help from you guys I have a battery picked out though I have not finalised the purchase yet so this might change depending on this thread.

Roamer 24-230SMART3 - 24V 230Ah LiFePO4 Lithium Leisure Battery + Free Consultation

Buy the Roamer 24-230SMART3 and get a FREE electrical system design consultation worth £120. The Roamer 24-230SMART3 is a high power 24V 230Ah LiFePO4 battery for install in a campervan, motorhome, boat or tiny house. Includes 250A continuous discharge, active balancing, Roamer BMS bluetooth...

roamerbatteries.com

So I now need to look out a charge controller for all of this.

From an earlier conversation @Rednecktek told me I need a 40A controller although this was slightly off-topic at the time so I didn't go into details on this.
The supplier of the battery recommends Victron product (as do a lot of the videos I see online) but there are just SOOOOooooo many. ??

Can you guys recommend one for me that will scale if I add any more batteries/components to my build? I dont think I'll have room for any more panels so that should be fairly fixed.

I do intend to use an inverter (probably around 2500-3000W) and a dc/dc charger to the mix and would like to have a access to control and monitor through the Bluetooth app or similar.

Thanks in advance for any and all help with this.

Jason

I like epever 40amp tracer 4210an charge controller. I have 3 and run 14x 240w panels using them on a 24v system.
Theres a nice deal for like $150 you get a
Cc that's normal $130 ish with the $30 external display and a USB cable that's usually $12 and a battery temp sensor . It's on Amazon still I think. Guess not

EPEVER 40A MPPT Charge Controller, Solar Panel Charge Controller Mppt 100V PV Input Negative Grounded Solar Regulator 12V/24V Auto with LCD Display for Gel Sealed Flooded Lithium Battery https://a.co/d/7keGFV8

 

[73powerstroke]

This one is a bit more robust
And 150v voc pv input might help.

EPEVER 40A MPPT Charge Controller, Solar Panel Charge Controller Mppt 100V PV Input Negative Grounded Solar Regulator 12V/24V Auto with LCD Display for Gel Sealed Flooded Lithium Battery https://a.co/d/7keGFV8