I need help selecting a busbar size

[Santa]

@Santa what sort of loads are you looking at servicing? Never hurts to buy a busbar bigger than needed as they are relatively inexpensive.

I am adding things up now. Most is just for shorter bursts, but a few like a fridge , laptop and light for longer time.

 

[Santa]

When it comes to busbars, short answer could be "Trust me from experience, you want more than one." and a longer answer follow-up "When it comes to using DIY solar, you never seem to have enough spots to hook stuff up, because you will regularly be adding, changing, reconfiguring, etc.."

Coming from a background in ham radio, we never use chassis ground for anything. We always run a ground wire back to the battery for anything. That is where a negative bus bar comes in. I don't want a bunch of wires hanging off the battery ground, so a single wire to a busbar is a better choice for me. Same for the positive side.

But how big should I select - in Amps? For Will's newest blueprint with the dc-dc renogy mppt alternator one? The link shows up to 250amp on the Amazon link. I plan to expand too. So, what you're saying is, all grounds will attach on the (negative) busbar on the wooden board you make right? I will get the red and black separately then. Will will be updating the blueprint he says. Thank you. P.S. After I get everything settled and on the road full-time I plan on learning HAM!

 

[Steve_S]

Don't forget your Coffee Maker and any items that have a parasitic draw even when not in use.

I have to share this: Coffee Maker ! Ohhh boy, people go blind in small ways costing them. How many "Energy Conservative" people realize that a Coffee Maker without a Thermal Carafe (simple glass carafe) are using one of the worst appliances out there for Solar Power ? Not Many ! and these are anywhere from 1200 to 1500 watts to boot. Using a maker tat has a Thermal Carafe that has no warmer is far more efficient. You also get better tasting coffee (doesn't get burnt by the warmer) and it stays hot till you empty the carafe, even 10 hours later !

One small and simple appliance that many of us depend on but one which can cost you huge power usage. I have used several of these ovr the decades and they haven't ben the easiest to find and some were downright junk (Black & Decker for one, leaked, zapped one daughter good (she was lucky) I have since discovered a Very Good one which I can only praise, se link below.

Oster Stainless Steel 10-Cup Thermal Coffee Maker - BVSTPSTX95-033 : Amazon.ca: Home

Oster Stainless Steel 10-Cup Thermal Coffee Maker - BVSTPSTX95-033 : Amazon.ca: Home

www.amazon.ca

 

[Santa]

Don't forget your Coffee Maker and any items that have a parasitic draw even when not in use.

I have to share this: Coffee Maker ! Ohhh boy, people go blind in small ways costing them. How many "Energy Conservative" people realize that a Coffee Maker without a Thermal Carafe (simple glass carafe) are using one of the worst appliances out there for Solar Power ? Not Many ! and these are anywhere from 1200 to 1500 watts to boot. Using a maker tat has a Thermal Carafe that has no warmer is far more efficient. You also get better tasting coffee (doesn't get burnt by the warmer) and it stays hot till you empty the carafe, even 10 hours later !

One small and simple appliance that many of us depend on but one which can cost you huge power usage. I have used several of these ovr the decades and they haven't ben the easiest to find and some were downright junk (Black & Decker for one, leaked, zapped one daughter good (she was lucky) I have since discovered a Very Good one which I can only praise, se link below.

Oster Stainless Steel 10-Cup Thermal Coffee Maker - BVSTPSTX95-033 : Amazon.ca: Home

Oster Stainless Steel 10-Cup Thermal Coffee Maker - BVSTPSTX95-033 : Amazon.ca: Home

www.amazon.ca

I do a French press now (pour over) or instant. Works great and only propane or butane used for about a minute and a half to heat the water. I put more hot water in a thermos for later if you want more. EDIT: unplug anything you don't use all the time. I do that at home and turn the circuits off at the circuit breaker in the sticks and bricks unless I use it every day. I've heard it called "vampire energy". In case anyone didn't know, unplug everything you don't use all the time per the Electric company. P.P.S. a rocket stove would heat the water with twigs for basically free!

 

[Will Prowse]

Blueprint is now updated: https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

 

[Steve_S]

Blueprint is now updated: https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

Excellent Will ! gotta love simple, no way around that.
Question. Assuming the alternator is the same as used for the vehicle itself and it's 12V battery, would this not overrun the alternator if it was loaded running heater/ac or charging the vehicle battery as well ? Now in an older non-computer vehicle, it's not a big deal to go from an 80A to 120A alternator, tad more tricky with computerised cars but not crazy hard either.

BTW in the last couple of years, the "jobber rebuilt alternators" have become junk due to the cheapness of parts, if anyone is looking for a good unit, ensure you get an original (out of a wreck) or a Factory Rebuilt one, which will cost a bit more than the jobber ones but will last.

 

[Will Prowse]

yes, but on the blueprint, it wont matter what size you choose because the lugs are touching each other. You could use a small bus bar and it would work fine. Thats why its wired like that.

And yes, use both of them as suggested in package

 

[Will Prowse]

Excellent Will ! gotta love simple, no way around that.
Question. Assuming the alternator is the same as used for the vehicle itself and it's 12V battery, would this not overrun the alternator if it was loaded running heater/ac or charging the vehicle battery as well ? Now in an older non-computer vehicle, it's not a big deal to go from an 80A to 120A alternator, tad more tricky with computerised cars but not crazy hard either.

BTW in the last couple of years, the "jobber rebuilt alternators" have become junk due to the cheapness of parts, if anyone is looking for a good unit, ensure you get an original (out of a wreck) or a Factory Rebuilt one, which will cost a bit more than the jobber ones but will last.

Oh it could damage the alternator. But if its a van/rv/truck etc, it will handle it no problem. It is a smart dc dc charger with temp comp and current limiting. And if you have solar, it likes to decrease alternator charging to 25 amps. Which even a car alternator can handle.

 

[Santa]

Blueprint is now updated: https://www.mobile-solarpower.com/simplified-400-watt-fewer-wires-and-alternator-charging.html

OK, now I see the pic says to use 250A busbar. Thanks for taking the time to do this today Will! You're the best!

 

[Rootboy]

What we are really talking about is a "Power distribution block". That makes finding them on the web easier. ;>

Here's one that ought to do:

Galco

www.galco.com

After posting this I got to wondering about its suitability for use with aluminum wire. You have to go to the Erico site for the information, but they are suitable for use with aluminum.

 

[Santa]

What we are really talking about is a "Power distribution block", that makes finding them on the web easier. ;>

Here's one that ought to do:

Galco

www.galco.com

After posting this I got to wondering about its suitability for use with aluminum wire. You have to go to the Erico site, but they are suitable for use with aluminum.

Will said to get a 250 Amp. It looks pretty though! ty

 

[erik.calco]

@Santa I'm debating a DC panel with breakers because it is starting to look economical as well as being an all-in-one. But, this is for home, not vehicle, where space isn't as limited. I'll still have a big fuse within 7" of battery bank (+) because that's there to protect the bank and its wires.

 

[Santa]

@Santa I'm debating a DC panel with breakers because it is starting to look economical as well as being an all-in-one. But, this is for home, not vehicle, where space isn't as limited. I'll still have a big fuse within 7" of battery bank (+) because that's there to protect the bank and its wires.

DC Panel? I am following Will's blueprint (he updated it yesterday).

 

[erik.calco]

DC Panel? I am following Will's blueprint (he updated it yesterday).

I'm sure it's overkill for what you're doing, but a DC Breaker Box would combine a bus bar and breakers for DC distribution in one. It opens the door to using those pop in breakers instead of having a stand alone breaker for each inverter or w/e distribution you add to your battery bank. It seems economical because for w/e reason, the standalone breakers seem to cost a lot more than the pop-in ones, in part because they need more protective housing. But, I'm just starting to look into it.

EDIT: Some of them come with a battery (-) bus bar, too.

I'm also looking for ways to limit or contain risk, and that is cultivating an appreciation for metal boxes.

 

[Kiwi DIYer]

Hi, I have had 2 bus-bars made at a local elections hardware manufacturer. They are rated to 500 amps, twice the rating of my 250 amp main fuse. From these I will be attaching the solar controller, the inverter and battery wire's.
Just picked up the 2 bus-bars that I had made. They have an isolation mounting volt and are confirmed to be rated at 470 amps guaranteed.