Connect Parallel Feeds to Threaded Busbar
- #1
I'm planning on paralleling four LifePower 48V 100AH rack mount batteries. My original plan was to make a bunch of cables for them from 4/0. The terminals allow cables to run up/down so my plan was to run from one terminal to the next in the rack. BUT... recent Will video he mentioned, "of course if you were using more than one battery, you might want to use a busbar" - is he suggesting running everything to a busbar with terminals (which I have seen but don't see a huge advantage) OR is the suggestion to get copper stock, drill out where terminals are, and "hard connect" all the batteries.
Searchs for "busbar" mainly turned up the former. For those who have made busbars to connect their batteries, what did you use for insulation for the exposed copper between batteries?
JWLV
One Million Dollars!
- #3
I use busbars whenever possible. But sometimes it's not so easy to get the batteries in the right position/orientation to connect busbars. Cables are much easier since you can bend them, loop them, do whatever you want to get from point A to point B.
For insulation, I use large heat shrink tubing. I don't know if that's the proper way to insulate busbars, but that's what I use.
- #5
I'm planning on paralleling four LifePower 48V 100AH rack mount batteries. My original plan was to make a bunch of cables for them from 4/0. The terminals allow cables to run up/down so my plan was to run from one terminal to the next in the rack. BUT... recent Will video he mentioned, "of course if you were using more than one battery, you might want to use a busbar" - is he suggesting running everything to a busbar with terminals (which I have seen but don't see a huge advantage) OR is the suggestion to get copper stock, drill out where terminals are, and "hard connect" all the batteries.
Searchs for "busbar" mainly turned up the former. For those who have made busbars to connect their batteries, what did you use for insulation for the exposed copper between batteries?
I did mine this way.
It's going to be up to your physical constraints and budget.
I used different gauge cable from Ben but used same panel and breakers.
- #7
It's worked so far. 3 years and counting.
- #11
OK. Change of Plan - Can't do solid copper busbar because positive terminal is in line with breaker for each battery pack (see pic). It comes with short cables, but they are 16mm (which I think translates to 6AWG). I am putting 4 in parallel and will put a fuse off the positive for 300 Amp. I had planned on using 2/0 or 4/0, but the terminal on the battery is sooo small - looks like 1/4x20 (see the pic of the ring terminal on the wire that came with it). I guess they assume the short cables are to run a bunch in series? Not sure what to do. I had planned to make cables an crimp on ring terminals, but where will I get a ring terminal for 4/0 that fits something like 1/4x20?
-
2022-01-06 15.45.50.jpg
-
2022-01-06 15.46.39.jpg
-
2022-01-06 15.51.04.jpg
- #12
Cables to a bus would be my preference. Depending on conditions I would be looking to go #4 wire.
https://shop.pkys.com/Blue-Sea-2127-Maxibus-BusBar-250-Amps_p_2775.html
And get the cover for the bus.
Thanks for the link. When I originally said "busbar" I was thinking of a solid copper bar going from one terminal to the next. It there a harm in daisy chaining the connecting cables - a cable from 1+ to 2+, then a second cable from 2+ to 3+, then another from 3+ to 4+? Same for negative and then conencting cables go back to inverter from 1+ and 4-
- #13
Our battery racks for these actually have bus bars on the side that you connect to with a short cable. That would be my recommendation - that is, get a bus bar and connect to it with short cables off-set from the battery. You don't need the battery rack itself - just the idea of the bus bar with the short cables. Here's a picture of the side and you'd just connect to it with short cables typically. I wouldn't recommend daisy chaining if you have the ability to use a busbar.
- #14
Our battery racks for these actually have bus bars on the side that you connect to with a short cable. That would be my recommendation - that is, get a bus bar and connect to it with short cables off-set from the battery. You don't need the battery rack itself - just the idea of the bus bar with the short cables. Here's a picture of the side and you'd just connect to it with short cables typically. I wouldn't recommend daisy chaining if you have the ability to use a busbar.
View attachment 78748
I guess that's tinned copper with insulators holding it on to the rack? It's nice, but...more work...
- #15
And a followup question. If I'm running to a real cupper busbar, then the cable that connects each battery to the busbar does not need to be sized for the max current (250-300Amps), but the busbar and the cables connecting them to the inverter do. The short cables that came with the battery are 6AWG. I think they can carry about 65 amps. Too small?
Edit: I did more maths (who knew solar was so math laden). If max output of the inverter is 240voltx50amp=12000 watts, then the max ciming from the battery at 48 volts is 250A, which would run on 4/0, and the max current from each battery is 62.5A which those smaller cables that came with the battery shoudl handle. All of this assumes I ignore momentary inrush/start currents. Is this reasonable?
Last edited:
- #16
Our battery racks for these actually have bus bars on the side that you connect to with a short cable. That would be my recommendation - that is, get a bus bar and connect to it with short cables off-set from the battery. You don't need the battery rack itself - just the idea of the bus bar with the short cables. Here's a picture of the side and you'd just connect to it with short cables typically. I wouldn't recommend daisy chaining if you have the ability to use a busbar.
View attachment 78748
Orderef mine last week and if you think you could DIY it it would cosr $150 more.not including shipping costs from all the vendors
- #17
Agreed - if you DIY the entire rack. But if you just mount your inverters and stack your batteries, you could run a few cables and a bus bar for pretty inexpensive - I can't imagine more than $50.... again this is just for the bus bar etc. Probably add some funds for a safety cover and mounting hardware and you are looking pretty for fairly affordable pricing. If you want a full rack that you can attach wheels to and very professional looking, I 100% agree you won't beat our price on this rack.
- #18
And a followup question. If I'm running to a real cupper busbar, then the cable that connects each battery to the busbar does not need to be sized for the max current (250-300Amps), but the busbar and the cables connecting them to the inverter do. The short cables that came with the battery are 6AWG. I think they can carry about 65 amps. Too small?
Edit: I did more maths (who knew solar was so math laden). If max output of the inverter is 240voltx50amp=12000 watts, then the max ciming from the battery at 48 volts is 250A, which would run on 4/0, and the max current from each battery is 62.5A which those smaller cables that came with the battery shoudl handle. All of this assumes I ignore momentary inrush/start currents. Is this reasonable?
Sounds good to me! Haha, seriously though, I know that the wire size we include with our products is rated at or above minimum requirements for the distance/amperage no problem. And if you are using a solid conductive busbar you will definitely be in overkill on hitting the requirements!
- #19
OK. I ordered 1/4"x1"x36" copper bars (110 copper) - they were $48 each on Ebay. 1/8" thick would have worked current capacitywise, but I thought it might bend around. Went looking for copper nuts and bolts, but those seem tough to find, so going with Stainless Steel (whcih seems to get along well enough with copper. Now to seach for insulated standoffs to mount the bars.
Source: https://diysolarforum.com/threads/parallel-connecting-four-48v-100ah-batteries-cables-or-busbar.33526/
0 Response to "Connect Parallel Feeds to Threaded Busbar"
Post a Comment