diy solar

diy solar

To solder or not to solder?

Source, Battery, Charge Controller, Panels, etc.
Fuse/breaker as close as practical to Source.
Wire/Cable that will conduct MAXIMUM load (inverter/lights/whatever)

Oversized circuit protection, or undersize wire/cable is dangerous.
Undersized cables will 'Starve' the load and heat up,
With an Oversize fuse/breaker the wire/cable can get VERY hot and the protection won't activate.

Fuses/Breakers are used in TWO different ways,
1. To protect wires/cables when they fail. (Damage, corrosion, etc.)
2. To protect a specific appliance from excessive load draw.

The fuse/breaker heats up first and blows/trips BEFORE the cable heats up and melts insulation, start fires on the wires/cables, and are *Usually* sized a little big, or 'Slow Blowing' to allow momentary over demands to pass without blowing/tripping.

The device protection (fuse/breaker) is sized MUCH closer to the operational load the device is *Supposed* to demand.
There is a reason so many devices come with their own circuit protection that can occasionally burn/trip, and the reason is they are sized specifically to protect the device and not protect the main line.

------------

SO!
Now you have a battery/batteries of 1,000 amps,
Now you have cables capable of 200 amp supply to inverter,
Now you have circuit protection, say a fuse at the battery to cable connection that will melt at 220 amps if the cables are dead short circuited together...

You have a sharp edge rub through the insulation and contact something that's chassis 'Grounded',
Something like sheet metal that only takes 30 amps to melt into molten slag, orange hot pools of liquid metal...
TWO things are going to happen fairly quickly,

The first is the 220 Amp fuse IS NOT going to burn and disconnect the batteries from the cable.
The 30 amps required to melt thin steel into puddles is not going to trip a 220 Amp protection device.
60 amps will melt/weld 2 pieces of 1/4" steel AND the welding rod, and still not trip the circuit protection.
The 'Smart' money is spent on insulation & armor for the battery cables ANYWHERE they touch anything that can damage insulation.

The second thing that's going to happen is you will have orange/yellow hot ball of molten metal dropping on anything under them.

Hopefully you have a $15 smoke detector stuck right above your primary wiring!

-----------------

Watts ÷ Amps = Volts
Watts ÷ Volts = Amps
Amps x Volts = Watts
Volts x Amps = Watts
This is a constant.

The LOAD determines how many Amps gets dragged through any given wire/cable/terminals/connection points.

1,000 Watt Load, powered by a 12 volt battery/batteries in parallel,
1,000 Watts ÷ 12 Volts = 83.33 (84) Amps.
Discounting any resistance from terminal ends, stacking terminals, etc
That's a 4 Ga. Wire size minimum to conduct that 84 Amps,
4 Ga wire will conduct 92.3 Amps
(Always round UP and size UP)

I use the Brown & Sharpe scale, once I find amperage, I simply look up the amp load (rounded up) and then see what wire gauge size handles the amperage.
This is the scale the American Wire Gauge is based on, adopted almost directly.
Find your amperage in the 'Amps' column, follow far left for wire size.

B&Sscale01.gif

--------------

Everyone will do what's best for them...

I personally won't mount something with high amperage directly on anything flammable.
While plywood is an electrical insulator, the glue & wood are flammable.

A small piece of sheet metal from the hardware store behind the inverter, charge controller, etc is a heat shield/fire retardant.
For the DIY types that scrounge, stoves, fridge/freezers, washers/dryers, anything made of sheet metal that's handy will donate.
Another source is stove pipe that snaps together (steel or aluminum).

I keep anything flammable to a minimum in my unattended solar/machine room.
I've seen big truck battery cables melt through the heat treated frame, battery cables melt through angle iron battery racks, etc.
Nothing to catch fire, so the things I saw didn't burn completely down, or they would have been in the junk yard instead of being repaired, but I tried to learn from the experiences...
 
Santa said:
So you say use resin but JeepHammer says not to. Confusion has definitely set in, LOL @offgriddle
Click to expand...
Well, resin flux is non corrosive and used on copper and brass. Acid is a more aggressive corrosive and used to solder steel and other metals. You wouldn't want acid etching away at sensitive electricial wire connections, printed circuit boards and components.
 
offgriddle said:
Well, resin flux is non corrosive and used on copper and brass. Acid is a more aggressive corrosive and used to solder steel and other metals. You wouldn't want acid etching away at sensitive electricial wire connections, printed circuit boards and components.
Click to expand...

The question is with Flux?

Rosin is fine for electrical solder, most electrical solider will have a rosin core or nothing for a core material.
If it's sold core, use a little rosin flux.

No acid core or acid flux ever, no acid cleaners ever.

A wire brush or Emery cloth to clean heavy tarnish or corrosion.
Copper is expensive, I try to clean it up and use it when I can, clean copper solders well.
 
JeepHammer said:
The question is with Flux?

Rosin is fine for electrical solder, most electrical solider will have a rosin core or nothing for a core material.
If it's sold core, use a little rosin flux.

No acid core or acid flux ever, no acid cleaners ever.

A wire brush or Emery cloth to clean heavy tarnish or corrosion.
Copper is expensive, I try to clean it up and use it when I can, clean copper solders well.
Click to expand...
Yes, it's good to clean it up before you flux it up!
 
I usually get rosin core, I ALWAYS over flux and I hate cleaning up the flux mess. :(
Clean takes a lot less flux.
 
JeepHammer said:
I usually get rosin core, I ALWAYS over flux and I hate cleaning up the flux mess. :(
Clean takes a lot less flux.
Click to expand...
Don't tell anyone, but I use flux AND resin core solder together, I love flux, helps the solder flow in and around the work and bond, cleans the tip of the soldering iron/gun and transfers heat so much quicker and more effectively ... sssshh it'll be our secret!
 
offgriddle said:
Don't tell anyone, but I use flux AND resin core solder together, I love flux, helps the solder flow in and around the work and bond, cleans the tip of the soldering iron/gun and transfers heat so much quicker and more effectively ... sssshh it'll be our secret!
Click to expand...

I was talking torches and heavy lugs.
I've become pretty fond of the cleaning/flux tape, I don't over flux with it.
Beats the sponge & flux to tin the tip I just never quite liked.
As connections get smaller I need bigger and bigger magnifiers, my bionic eyes are in the same place my bionic back, jet pack and flying car are.. ;)
 
JeepHammer said:
Source, Battery, Charge Controller, Panels, etc.
Fuse/breaker as close as practical to Source.
Wire/Cable that will conduct MAXIMUM load (inverter/lights/whatever)

Oversized circuit protection, or undersize wire/cable is dangerous.
Undersized cables will 'Starve' the load and heat up,
With an Oversize fuse/breaker the wire/cable can get VERY hot and the protection won't activate.

Fuses/Breakers are used in TWO different ways,
1. To protect wires/cables when they fail. (Damage, corrosion, etc.)
2. To protect a specific appliance from excessive load draw.

The fuse/breaker heats up first and blows/trips BEFORE the cable heats up and melts insulation, start fires on the wires/cables, and are *Usually* sized a little big, or 'Slow Blowing' to allow momentary over demands to pass without blowing/tripping.

The device protection (fuse/breaker) is sized MUCH closer to the operational load the device is *Supposed* to demand.
There is a reason so many devices come with their own circuit protection that can occasionally burn/trip, and the reason is they are sized specifically to protect the device and not protect the main line.

------------

SO!
Now you have a battery/batteries of 1,000 amps,
Now you have cables capable of 200 amp supply to inverter,
Now you have circuit protection, say a fuse at the battery to cable connection that will melt at 220 amps if the cables are dead short circuited together...

You have a sharp edge rub through the insulation and contact something that's chassis 'Grounded',
Something like sheet metal that only takes 30 amps to melt into molten slag, orange hot pools of liquid metal...
TWO things are going to happen fairly quickly,

The first is the 220 Amp fuse IS NOT going to burn and disconnect the batteries from the cable.
The 30 amps required to melt thin steel into puddles is not going to trip a 220 Amp protection device.
60 amps will melt/weld 2 pieces of 1/4" steel AND the welding rod, and still not trip the circuit protection.
The 'Smart' money is spent on insulation & armor for the battery cables ANYWHERE they touch anything that can damage insulation.

The second thing that's going to happen is you will have orange/yellow hot ball of molten metal dropping on anything under them.

Hopefully you have a $15 smoke detector stuck right above your primary wiring!

-----------------

Watts ÷ Amps = Volts
Watts ÷ Volts = Amps
Amps x Volts = Watts
Volts x Amps = Watts
This is a constant.

The LOAD determines how many Amps gets dragged through any given wire/cable/terminals/connection points.

1,000 Watt Load, powered by a 12 volt battery/batteries in parallel,
1,000 Watts ÷ 12 Volts = 83.33 (84) Amps.
Discounting any resistance from terminal ends, stacking terminals, etc
That's a 4 Ga. Wire size minimum to conduct that 84 Amps,
4 Ga wire will conduct 92.3 Amps
(Always round UP and size UP)

I use the Brown & Sharpe scale, once I find amperage, I simply look up the amp load (rounded up) and then see what wire gauge size handles the amperage.
This is the scale the American Wire Gauge is based on, adopted almost directly.
Find your amperage in the 'Amps' column, follow far left for wire size.

View attachment 2327

--------------

Everyone will do what's best for them...

I personally won't mount something with high amperage directly on anything flammable.
While plywood is an electrical insulator, the glue & wood are flammable.

A small piece of sheet metal from the hardware store behind the inverter, charge controller, etc is a heat shield/fire retardant.
For the DIY types that scrounge, stoves, fridge/freezers, washers/dryers, anything made of sheet metal that's handy will donate.
Another source is stove pipe that snaps together (steel or aluminum).

I keep anything flammable to a minimum in my unattended solar/machine room.
I've seen big truck battery cables melt through the heat treated frame, battery cables melt through angle iron battery racks, etc.
Nothing to catch fire, so the things I saw didn't burn completely down, or they would have been in the junk yard instead of being repaired, but I tried to learn from the experiences...
Click to expand...
Let me see if I understand you JeepHammer and ask you this. My inverter is 2,000 watts/4,000 watts peak.

1. If I were to use something that was 2,000 watts I would need 166 Amp main fuse right (200amp)?

2. But, if I were to use something that used 4,000 watts for a short burst, would I need a 333 amp (350 amp) main fuse? Or do you only count the regular wattage, i.e. 2,000 watts of inverter to size my fuse? I hope you get what I mean....

3. Likewise, should I just use 4/0 cables for the entire system, except the DC and solar connections which will be 10awg? According to your chart, it looks like it. P.S. I am looking at all my electrical items and highest thing I think I have is the portable heater @1000 watts on low and 1500 watts on high (if I were to use it). I have a jigsaw, but don't know the amps.

Will's book says to use 210amp fuse for a 2,000 watt inverter. (250amp)

4. Can you show me what a crack head lighter is? I never saw one before... Are you talking about a stick lighter for a fireplace? If I use the larger wire 4/0 I would need a propane torch instead?

5. Should I use the heavy duty lugs on all connections or just the inverter to battery cables? I hope I am not bugging you... :)
 
 
Last edited:
Santa said:
Let me see if I understand you JeepHammer and ask you this. My inverter is 2,000 watts/4,000 watts peak.

1. If I were to use something that was 2,000 watts I would need 166 Amp main fuse right (200amp)?
Click to expand...

The math is easy,
2,000 Load (inverter) ÷ 12 Volts = 166.66 (167) Amps.
0 Ga cable, and you would want a little in the breaker/fuse, so 175 would be about right.
200 would protect the Cables from serious overload, but it would depend on the inverter if it was protected or not.
Most inverters have protection for themselves...

2. But, if I were to use something that used 4,000 watts for a short burst, would I need a 333 amp (350 amp) main fuse? Or do you only count the regular wattage, i.e. 2,000 watts of inverter to size my fuse? I hope you get what I mean....
Click to expand...

Inverters *Often* have their own device protection,
Your cables are what YOU need to protect.
If you don't think your inverter has protection, stop about 220 amps, the 0 Ga. cables should survive without issues.

3. Likewise, should I just use 4/0 cables for the entire system, except the DC and solar connections which will be 10awg? According to your chart, it looks like it. P.S. I am looking at all my electrical items and highest thing I think I have is the portable heater @1000 watts on low and 1500 watts on high (if I were to use it). I have a jigsaw, but don't know the amps.
Click to expand...

'Surge' will last somewhere between milliseconds and 2 seconds before inverter shuts down.
Massively oversize cables aren't going to stop the shut down since 'Surge Capacity' mostly comes from INSIDE the inverter.
it will be an internal shutdown inside the inverter and your line protection is for the cables.

Will's book says to use 210amp fuse for a 2,000 watt inverter. (250amp)
Click to expand...

Good advise.

4. Can you show me what a crack head lighter is? I never saw one before... Are you talking about a stick lighter for a fireplace? If I use the larger wire 4/0 I would need a propane torch instead?
Click to expand...

Covered.

5. Should I use the heavy duty lugs on all connections or just the inverter to battery cables? I hope I am not bugging you... :)
Click to expand...

On a 2,000 Watt nominal (normal load max) inverter I would use heavy lugs at the batteries.
At the inverter I would use plated (tinned) tubing style, but I would pick lugs that had a lot of 'Meat' (surface area) around the holes. The more contact surface area the more current will be conducted through the terminals.

If it's a socket (hole with a screw in the side) terminal for raw wire on the inverter,
I would 'Tin' my cable before I stuck the cable in and cranked the screw down.
Stray strands that escape socket or screw contact do no good at all.
The wires have to be solidly connected to do much of anything.
 
JeepHammer said:
The math is easy,
2,000 Load (inverter) ÷ 12 Volts = 166.66 (167) Amps.
0 Ga cable, and you would want a little in the breaker/fuse, so 175 would be about right.
200 would protect the Cables from serious overload, but it would depend on the inverter if it was protected or not.
Most inverters have protection for themselves...



Inverters *Often* have their own device protection,
Your cables are what YOU need to protect.
If you don't think your inverter has protection, stop about 220 amps, the 0 Ga. cables should survive without issues.



'Surge' will last somewhere between milliseconds and 2 seconds before inverter shuts down.
Massively oversize cables aren't going to stop the shut down since 'Surge Capacity' mostly comes from INSIDE the inverter.
it will be an internal shutdown inside the inverter and your line protection is for the cables.



Good advise.



Covered.



On a 2,000 Watt nominal (normal load max) inverter I would use heavy lugs at the batteries.
At the inverter I would use plated (tinned) tubing style, but I would pick lugs that had a lot of 'Meat' (surface area) around the holes. The more contact surface area the more current will be conducted through the terminals.

If it's a socket (hole with a screw in the side) terminal for raw wire on the inverter,
I would 'Tin' my cable before I stuck the cable in and cranked the screw down.
Stray strands that escape socket or screw contact do no good at all.
The wires have to be solidly connected to do much of anything.
Click to expand...
Thank you so much again! I really appreciate all your help! Sometimes I'm still a little confused though. I hope you don't mind me asking more questions? This has turned out to be more complicated than I expected. I want to learn though and WILL learn. I may be ignorant, but I'm not stupid, lol.
 
Santa said:
Thank you so much again! I really appreciate all your help! Sometimes I'm still a little confused though. I hope you don't mind me asking more questions? This has turned out to be more complicated than I expected. I want to learn though and WILL learn. I may be ignorant, but I'm not stupid, lol.
Click to expand...
So, with all your advice and Will's blueprint I am ordering these TODAY (unless someone tells me otherwise) any place I can find them. I don't want to use Amazon, if possible. I NEED TO GET THIS ORDERED RIGHT AWAY. If you know of a better or faster way or place to get them, PLEASE let me know . I would love recommendations! If I got anything incorrect, please tell me:

1. (Four) 4 of these heavy duty lugs for battery terminals only (I have 2 battleborns) so I need (4) Heavy Duty Lugs. The terminals are 5/16": https://www.electricalhub.com/generic-151-heavy-duty-tin-plated-copper-cable-lugs-17

2. Both red and black- 3M Glue heat shrink -one each: https://www.electricalhub.com/3m/polyolefin-dual-wall-heat-shrink-tubing/eps-300-3-4-48-red and https://www.electricalhub.com/3m/polyolefin-dual-wall-heat-shrink-tubing/eps-300-3-4-48-black

3. Solder: https://www.ebay.com/itm/BernzOmati...2ad9538ed6:g:ltYAAOSwoGVdzA-l&redirect=mobile

4. 5/16" Brass nuts and bolts at the battery terminals, so I need 4 sets of each. (The Battleborn batteries came with 2 sets of steel nuts and bolts with brass washers. Why did they send me two different sizes (lengths) of bolts?) I looked at Home Depot and didn't see the brass ones. Are these the correct ones to order? https://www.ebay.com/itm/M4-Solid-B...hash=item286f084a6f:m:mTPJec2C1CXSO40fmNljnLQ It looks like they're coming from China though??

5. 1/0 ought tinned copper cable for battery to inverter (red and black): https://www.amazon.com/gp/product/B01MD1XRSL/ref=ox_sc_act_title_3?smid=A2TN19FHI2Z5KL&psc=1

6. 4 AGW Tinned copper cable for the rest of the system's cables: https://www.ebay.com/itm/8-6-4-2-1-...ry-Copper-Cable/252712989985?var=551692067407

7. Battery to battery cables for 2 batteries. I forget what gauge to buy at this point. I was going to buy 2AGW?? IS THIS CORRECT?

8. 10 AWG for DC appliances https://www.amazon.com/gp/product/B01MD1XRSL/ref=ox_sc_act_title_3?smid=A2TN19FHI2Z5KL&psc=1

9. 10 AWG Cable for controller to panels https://www.amazon.com/RENOGY®-20ft-Adaptor-Female-Connectors/dp/B00JH1QD54/ref=as_li_ss_tl?ie=UTF8&dpID=21vybvmksjL&dpSrc=sims&preST=_AC_UL160_SR160,160_&psc=1&refRID=XME839MTEHE4D6JNZ3Y9&linkCode=sl1&tag=vehicledwelling-20&linkId=aaa43fdc79e421658f1c254664214b2f

8. 250amp Fuse ANL

9. Hammer crimper https://www.ebay.com/itm/TEMCo-Batt...rminal-Welding-Lug-Crimping-Tool/281912922165

10. Connectors: https://www.ebay.com/itm/270-PCS-He...d-Terminals-Set-W-Crimp-Ring-But/233309570737

11. Heavy connectors: https://www.ebay.com/itm/56Pcs-8-4-...able-Tinned-Copper-Ring-Terminal/323759799808

12. Wire stripper tool that will strip the above sizes from 1/0 to 10AWG... any link please?

13. Can you recommend a link for the correct Armor? There are so MANY different types at Home Depot...any link?

14. Two Battery boxes or one large one that holds two batteries if that's possible? Recommendations? Can you put 2 in a box? I saw someone use a large Tupperware box?

If I forgot something, please tell me. Thanks in advance! Here is my blueprint https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html
 
Last edited:
The links you have at 5 and 6 do not say tinned copper wire, they say tinned crimp lugs.
Just so you know.
 
Supervstech said:
The links you have at 5 and 6 do not say tinned copper wire, they say tinned crimp lugs.
Just so you know.
Click to expand...
I just checked. #5 is copper wires with lugs and whatever in a kit? #6 is copper wire???? I don't know what you are seeing
 
Santa said:
I just checked. #5 is copper wires with lugs and whatever in a kit? #6 is copper wire???? I don't know what you are seeing
Click to expand...
Your description says tinned copper wire for both points.
The linked items are not tinned copper wire.
 
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