Solar cable splicing

[Young_Waller]

Greetings, I am switching to a Victron MPPT solar controller (away from my gopower PWM) for my 200W panel. This is on a 2024 E-pro 19FD. The Victron is not a clean surface mount design, so I'm thinking about changing the controller location by cutting into the wires somewhere out of sight.

Question: any advice on the best way to splice the cables where they now feed the gopower? The cables are fairly heavy gauge (I would guess 10 or 12). I don't know how picky the solar systems are about the splice -- amount of contact, material, etc...

Thanks for any advice.

[tonytony3]

with 200w only i don't think it's that picky...but here's something to consider too, voltage drop...chart:

https://assets.bluesea.com/files/res...on_chartlg.jpg

[NJKris]

I haven't redone my Geopro solar yet to accommodate an additional LiFePO4 I have designs for, but I would use solar M4 solar connectors, industry standard, made for weatherproof solar connections, low resistance.

[Bob K4TAX]

Originally Posted by Young_Waller

Greetings, I am switching to a Victron MPPT solar controller (away from my gopower PWM) for my 200W panel. This is on a 2024 E-pro 19FD. The Victron is not a clean surface mount design, so I'm thinking about changing the controller location by cutting into the wires somewhere out of sight.

Question: any advice on the best way to splice the cables where they now feed the gopower? The cables are fairly heavy gauge (I would guess 10 or 12). I don't know how picky the solar systems are about the splice -- amount of contact, material, etc...

Thanks for any advice.

I would strip the ends of each piece, twist the original wire and new wire conductors together maintaining noted polarity, and solder them with rosin core silver bearing solder. Then use whatever insulation method you desire. I prefer to use shrink tubing that shrinks size when heated. Just remember to put it in place before twisting and soldering.

Please, no added connectors.

Bob

[DJ252]

Gonna guess you're dealing with 10ga wire.

When I did the same (removed GoPower controller to install Victron) I just took a pic of the back of the GoPower, to record which wires were which and used a 10ga heat shrink buttsplice connector.

You do want the proper set of crimpers for them.

[Bob K4TAX]

Originally Posted by DJ252

Gonna guess you're dealing with 10ga wire.

When I did the same (removed GoPower controller to install Victron) I just took a pic of the back of the GoPower, to record which wires were which and used a 10ga heat shrink buttsplice connector.

You do want the proper set of crimpers for them.

That's why I said, "Please, no connectors". The strip and solder method requires no crimp tools or butt splices.

Bob

[Young_Waller]

Originally Posted by Bob K4TAX

I would strip the ends of each piece, twist the original wire and new wire conductors together maintaining noted polarity, and solder them with rosin core silver bearing solder. Then use whatever insulation method you desire. I prefer to use shrink tubing that shrinks size when heated. Just remember to put it in place before twisting and soldering.

Please, no added connectors.

Bob

Thanks Bob. Sounds like the least resistance method. Now, to not burn a hole in my bench seat.

[Bob K4TAX]

Originally Posted by Young_Waller

Thanks Bob. Sounds like the least resistance method. Now, to not burn a hole in my bench seat.

I suggest use a soldering iron and not an open flame torch.

Bob

[Aussieguy]

what amazes me is people who say no crimp and then they use wire nuts or them press down connectors that hardly have any surface area

solder is good if you got a good soldering iron..... and KNOW HOW to use it.

bad solders joints are real easy to produce..... use the wrong solder, don't get enough heat in the joint, not enough solder or wrong flux

a good crimper and some heat shrink has worked for a long long time
spend your mney on good SPLICE joiners..
Harbor freight or even the autoparts store their splices are terrible


EDIT..

save money on tools look at fleamarkets
bought a professional stripper and hand crimper max 8g ....... for about 20.00

[DJ252]

Originally Posted by Aussieguy

what amazes me is people who say no crimp and then they use wire nuts or them press down connectors that hardly have any surface area

solder is good if you got a good soldering iron..... and KNOW HOW to use it.

bad solders joints are real easy to produce..... use the wrong solder, don't get enough heat in the joint, not enough solder or wrong flux

a good crimper and some heat shrink has worked for a long long time
spend your mney on good SPLICE joiners..
Harbor freight or even the autoparts store their splices are terrible


EDIT..

save money on tools look at fleamarkets
bought a professional stripper and hand crimper max 8g ....... for about 20.00

Yeah. I didn't feel like getting into it.

If you have the right tools and skills, soldering is fine. Small ga. is fairly easy. As lrg. as 10ga. less so and it all depends on location. MC4 connectors are all crimped. With heatshrink, you can be connectorless with a lineman's splice. NASA uses it and various connectors.

With stranded wire, wire nuts are probably the worst method and are used all the time.

[Bob K4TAX]

I've never had a solder joint fail. I can't say the same for other methods. Crimping is fast easy and reliable......IF, and only IF you have the proper crimp tool for the specific type and size of connector. Otherwise, a crimp is highly unreliable.

I solder #10 gauge solid and stranded wire and smaller gauges using a soldering iron. Anything over #10 I resort to my butane torch. Using the correct solder and flux is very important. DO NOT use acid core solder for electrical connections. This is a real NO NO!

This is one of those topics that require the proper tools, methods, and knowledge. As often written, there are two kinds of folks: (a) those who know what they are doing , and (b) those who think they know what they are doing . And there is a big difference!

Bob