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Battery Busbars/Cab...
 
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Battery Busbars/Cables?

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pilgrimvalley
(@pilgrimvalley)
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Posted by: @kazetsukai
other 4/0ers here?

i use 4/0 copper cable and the price is about 7 dollars a foot now and the lugs are likely 2 bucks each....


   
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pilgrimvalley
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i tried to flatten copper pipe but decided it was a major pain in the rear to do and bought tinned copper busbars 2nd hand off of eBay when i can find them for cheap....

i also bought a lot of 1/4 inch thick copper busbar with predrilled holes and insulators in bulk from China but prefer the tinned copper busbars a bit more...

 


   
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pilgrimvalley
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the higher the voltage, the lower the amp draw and less amp draw is less heat on all components.....

so a 48-volt inverter will require smaller amperage rated busbars and cables (that is the reality)

24-volt systems are considered safe for most all code requirements but are still a force to be careful with...

a reinvented wheel may never get round (true sinusoid without a voltage drop/sag) without the proper driver board and sufficient size battery bank etc. to run the sensitive designed electronics of today....

a standard old style top load washing machine may be less of a problem than the new style front loaders (and considerably less money).....many suggest going to the top loader... less bells and whistles to malfunction..... or use the washer with the inverter that works correctly....

I use a combination of standard tinned copper busbars and hydraulically crimped copper cables in a 4P8S 24 volt LifePO4 battery making sure all cables are precisely the same length so the same resistance....

shipping heavy nonfunctional inverters with design malfunctions is a no go for most folks..... 200 to 300 dollars round trip likely or more.... running a space heater in this heat of summer is also a no go to make a bad design behave....🤣

expensive paperweights for the poor unsuspecting guinea pigs .....  🤔

ask for a trade in or request to get your money back.... not like the telephone answerer is going to reply.... 🤔🤔🤔 try a text message to them !!! 🤔

Happy flag day all   !!!! 😎

 


   
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(@dickson)
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ask for a trade in or request to get your money back.... not like the telephone answerer is going to reply

NO reply  because  shippiing  is too expensive  like 200 dollars by UPS  and full  insurance for damage or lost  shipment  is extra 200 dollars .    IT will be cheaper to  give full  refund  and not do the free repair . Too bad if the inverter is out of warranty  then shipping is 800 dollars  going out  and  coming .back . 

 


   
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(@aquaticslive)
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On 6/12/2023 at 12:24 PM, kazetsukai said:

No other 4/0ers here?

Always a fun subject.

The path from the inverter to my batteries won't allow me to run anything bigger than 1/0, but I would go with 4/0 if I could.  The price is low enough that it isn't that big of a deal.  

I am running a 12V 6K, but if your matching up with total amps I have a 4 foot run of wire from battery buss bars to the inverter.  I am running parallel 1/0 wires 2 for each.  That is the minimum that doesn't create too much heat for me.  Max 300 Amps is all that I can do continuously with that size and my heat limit that I set on the wires with Sids WiFi board.  I may add another parallel wire yet.  Each 1/0 is good for about 150 Amps before they start getting too warm.  Wire isn't that expensive so easy to add more.  I also use big bus bars that are way overkill with multiple current shunts, but the inverter is using wires from the buss bars to the inverter. 


   
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(@notmario)
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15 minutes ago, AquaticsLive said:

The path from the inverter to my batteries won't allow me to run anything bigger than 1/0, but I would go with 4/0 if I could.  The price is low enough that it isn't that big of a deal.  

I'm curious about what would prevent you from running larger cables...


   
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kazetsukai
(@kazetsukai)
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Topic starter  
Posted by: @aquaticslive
Always a fun subject.

Like I mentioned, 2AWG for 48V is more than plausible...

I think I'll stick by my suggestions for bus bars though, especially for anything under 48V. If you're gonna build something like that, its best to oversize it a bit. 


   
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(@aquaticslive)
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Posted by: @notmario
I'm curious about what would prevent you from running larger cables...

I am in a flat metal track about 5/8" tall but have plenty of width I could run 8 wires in it just can't get any taller.  My rig is an ambulance so built out very industrial.

Always test your temps is all I can say there.  I have seen some undersized setups getting very warm to save a few dollars not worth it. 

Adding to this quick I used to have a longer run of 2/0, but found the metal wire track and shortened the run and ran smaller wire, but going to add that extra wires now that think about it more.  The other reason to go with multiple cables for me is the terminal connectors got hot so doubling them up reduces that problem. 


   
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pilgrimvalley
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The bigger the copper wires or cables the better for high amp draws so they stay cooler.... 

Solid thick tinned copper busbars where possible and 4/0 cable can get lugs with almost any size bolt down predrilled in them....

Perhaps the issue is the old 12-volt inverter not allowing the larger lug to be connected...not sure of the hindrance without seeing the set up in a photo....

When one goes to a 24-volt set up the same power will be half the amp draw vs a 12-volt inverter,,,, but still a good idea to oversize all wires, busbars etc. for a cooler running system and allows for future changes and upgrades more easily...

The preorders are done says Sean so their price increased and no free shipping etc. so likely a few hundred more dollars...

The GS small size case without labels for this batch >>> of what wire goes where has to be a huge problem for this batch >>> and the toroidal hold downs fitting at an angle >>>... maybe next batch they will cure some of these assembly headaches and make them more user friendly!!!! 

I would think a simple label could be printed until they get the issue cured....

Even the interior wires should be labeled... a cheap label maker will do that for them.... 

Labels will also be a plus on the outside of a stainless steel case to hide the fingerprint smudges as stainless steel is a fingerprint magnet for sure.....

Have a great Thursday all !!!! 😎


   
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(@the-blind-wolf)
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Posted by: @notmario
Yeah, i do this too. Then a single pair of wires 2 the system bus bars, and 2 wires to inverter and other peripherals. Bus bars make a battery bank look very clean - plus the benefits of consistent resistance.

So basicly if I switch all my batts to use bus bars between the 12vs and then to a main bus bar and run a cable from that to the GS and Chargers, if it starts to heat up, add more :P.


   
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pilgrimvalley
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I bought 4 tin-plated copper bus bars with the holes already pre-drilled.... I found them on eBay when searching for copper busbars.... I think I have 160 dollars or slightly more in them for 4 of them including tax and delivery... they are brand new from 3 different sellers...

they are designed for grounding some other equipment 

they are 4 inches wide by 12 inches long and 3/8 inches thick I think 

they are quite heavy and I plan to use them on a new 8x8 ESS using 64 LiFePo4 280Ah version 3 cells in a 25.6-volt configuration...

48 volts will have less amp draw and of course run cooler than a 24-volt set up, and 12 volt will need even thicker cables etc to run cooler due to even higher amp draw for the same power (watts)

battery storage is the biggest expense in all my off-grid builds...

when comparing busbars and cables >>>> there is a good discussion on the DIYsolar forum that gets into the actual formulas and what not >>>> they use circular mils in the formula with resistance etc...

copper has less resistance so will run cooler than aluminum and cooler than steel of course...

the trick is the stand-off so there is no leakage into the insulator of the stand off...

more later

we got hammered with about 13 inches of snow the last 2 days so got to go...

i routinely use 4/0 on my inverter to battery connections,,,, not that much more money for cooler running cables...😎

 

 


   
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(@notmario)
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Posted by: @pilgrimvalley

I bought 4 tin-plated copper bus bars with the holes already pre-drilled.... I found them on eBay when searching for copper busbars.... I think I have 160 dollars or slightly more in them for 4 of them including tax and delivery... they are brand new from 3 different sellers...

they are designed for grounding some other equipment 

they are 4 inches wide by 12 inches long and 3/8 inches thick I think 

Extremely common in the comms industry. They're used to aggregate a ground for all the devices that use the tower.
160 for 4 feels a bit pricey, but not overly so - i'm used to buying them in bulk.
Though, it would be less expensive to go to a steel shop and cut/tap your own, though you'd have far more than you probably need. 😀

Posted by: @pilgrimvalley

they are quite heavy and I plan to use them on a new 8x8 ESS using 64 LiFePo4 280Ah version 3 cells in a 25.6-volt configuration...

48 volts will have less amp draw and of course run cooler than a 24-volt set up, and 12 volt will need even thicker cables etc to run cooler due to even higher amp draw for the same power (watts)

battery storage is the biggest expense in all my off-grid builds...

when comparing busbars and cables >>>> there is a good discussion on the DIYsolar forum that gets into the actual formulas and what not >>>> they use circular mils in the formula with resistance etc...

copper has less resistance so will run cooler than aluminum and cooler than steel of course...

the trick is the stand-off so there is no leakage into the insulator of the stand off...

more later

we got hammered with about 13 inches of snow the last 2 days so got to go...

i routinely use 4/0 on my inverter to battery connections,,,, not that much more money for cooler running cables...😎

Battery is undoubtedly the biggest expense in basically any off-grid or BESS setup - by far. Even if you use cheap batteries, it will catch up to you once you have to replace them in a few years. Especially if you actually USE it.

 

This post was modified 11 months ago by NotMario

   
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pilgrimvalley
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at 8000 cyles or 6000 cycles>>> they predict 13 year lifespan for the lifepo4..

battery or storage of electricity will hopefully get to be more efficient with time....

if you run the lifepo4 in the 20 to 80 range it is supposed to be better than fully charging them....

to have a 12000-watt inverter takes a lot of battery to run it for any time at all...as the battery draw would be more than that probably 13000 watts or so....

I would have to do the calculations again but an 89 percent or less efficient inverter will waste a lot of the solar PV generated electricity...

 

 

 


   
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(@dickson)
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they are 4 inches wide by 12 inches long and 3/8 inches thick I think .

One copper bar is like seven AWG  4/0 cables .   Four copper bar is 28  AWG 4/0 cables  and  each AWG 4/0 cables is 10 dollars a foot .  Worth 280 dollar AWG 4/0 cables  for 160 dollars of copper bus bar .   400 Amps time 28 cables is  11200 Amps  that the 4 copper bus bar can carry  if stack  1.5 inch thick .   11200A times 50V is 560000 watts . wow .  


   
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(@notmario)
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Posted by: @pilgrimvalley

at 8000 cyles or 6000 cycles>>> they predict 13 year lifespan for the lifepo4..

battery or storage of electricity will hopefully get to be more efficient with time....

if you run the lifepo4 in the 20 to 80 range it is supposed to be better than fully charging them....

to have a 12000-watt inverter takes a lot of battery to run it for any time at all...as the battery draw would be more than that probably 13000 watts or so....

I would have to do the calculations again but an 89 percent or less efficient inverter will waste a lot of the solar PV generated electricity...

I wasn't thinking of LiFePO4 when i said "cheap batteries". I was thinking of Lead Acid - where people usually cheap out on a BESS. - and will cost them more in the long run.

"Optimal Range" is in the eye of the beholder. LiFePO4 dislikes high charge states, so the more time it spends in lower charge states, the better. Not sure what point that begins to reverse (0% charge is instant death for LiFePO4). But i've read of 20-70% ranges resulting in more than a tripling of the EFC count. (AKA well over 20,000 EFCs)

I target 10% to 50%, and my setup optimized direct consumption. At 2.4 MWh total I/O, unsurprisingly, the batteries show 100% effective capacity. It equates to ~170 EFCs over 3 years.

 


   
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