Best Parallel Wiring Setups for Lithium Batteries (RV, Motor Home, Storage).

Today we compare different wiring setups for lithium batteries and see which one you should consider when setting up your battery.
Chapters:
Bad Setup: 2:56
Better Setup: 6:52
Best Setup (Bus bars): 10:02
Charging Results: 14:50

[@alfredoyeroporro2055]

The ground should be at the other end

[@ML-jr1yz]

The negative wire should go out to inverter from the last battery.

[@sfkenergy]

Yes we show this in configuration 2, this video was to show what happens if you don't do it this way.

[@scooter6334]

I have never tested it. Although at my bus bar I have all connections on one stud together. I have always figured this “in my mind” to make a better path 🤔. Nice video, I’ve never seen anyone that even has came close to this idea. Thanks for not making me feel stupid or waist full.

[@ny1t]

I bought four 300 AH batteries. Their manual recommended the connection you showed in the second setup. I contacted them and suggested they used the setup you had in the third setup. They changed their manual to reflect the change. I suspected the busbar would also induce a difference between each battery. Thank you for demonstrating the current draw from each battery. It helps get the point across.

[@SpatteL19]

In my opinion setup 2 and 3 are equally. But his test wasn't optimal. He already started with unevenly charged batteries and he should have changed them to 100% after each test. Of course you have small balancing currents and slightly uneven discharge currents in setup 2 right after the test in setup 1.

[@ny1t]

​@@SpatteL19 Nigel Calder explains it in the youtube video. Search for - The BEST way to Parallel Batteries on a Boat | Ask The Expert with NIGEL CALDER

[@user-uz7gu7of1v]

Great video, it helped me figure out why I was having shut downs in my system. Love the buss bar!

[@jasonbroom7147]

I like how you showed good, better, and best setups. This video is also a good demonstration of why it makes sense to go with higher voltage configurations, whenever possible. There will be less total drift across the cells, if they are all managed by a single BMS. If your video showed 4 batteries in parallel, and then showed those same 4 batteries in series, for 48 volts, you could demonstrate how that configuration results in even less drift than the bus bar connection you used.

[@houstonstarbuck]

Thanks. Yes a lot of us from the rv world are not initially knowledgeable. I love the 2 I bought from you for my rv. As noted...one of my batteries charges and discharges a bit faster...likely a byproduct of thor not running exactly the same lengths or it could be the busbar setup. It has not been a problem as they will equalize in normal use. Another thing you can let the rv folks know about is that lots of the stock battery setups were really undersized for the load. A 3000 watt inverter that can surge needs batteries that can support heavy load. My thor setup was a good example. The 100 batteries from the factory really didn't match up with my load ( ac running...other loads) and thus constantly put the batteries uner stress...sometimes in hot weather to the point of their bms shutting down. Your batteries support the load with ease....and you were very helpful with advice in the bms settings.

[@tomgarciaaz]

Good video. One of the odd ball things I have seen out there is others maintaining the battery to battery connections and doing bus bars.

[@davidgreen9957]

Also, Busbars make it very easy to remove one battery from the bank if needed.

[@user-de5ml9tm6e]

Thank you much? This was a huge help!

[@SpatteL19]

You should have charged the batteries to 100% before each test. Of course you have small balancing currents between the batteries and slightly uneven loads in setup 2 and 3 after the test of setup 1.

[@mrballbreeder3749]

Good info , good job.

[@dan32one44]

Good 👍 stuff..

[@Snailmailtrucker]

Great info ! Much appreciated ! Liked/Subscribed ! *FJB !*

[@websterbrauzer8373]

I love your video, this is extremely helpful for me as I’m setting up a 8S4P right now. The question is instead of a bus bar if you want them equally distant why don’t you just have one post where they’re all connected together? A single post and stack up all the connections that way they’re all equidistant?

[@patricioramos5133]

Very good teac😊

[@oilpressing]

your setup can be improved a little more if you think about it😇

[@redwood1957]

Are you referring to jumping battery to battery m?

[@inv1s_-]

Pretty sure people watching this video are not going to know... like me.

[@john_in_phoenix]

I have a 6 position busbar rated for 300 amps. The center 2 positions are occupied by the inverter and solar charge controller, the 4 outer (2 on either side) have 4 batteries with equal length cables and it seems pretty balanced in operation. I use Anderson connectors on them and have MRBF fuses on each battery.

[@sfkenergy]

We are working on a bus bar it is shaped like a hexagon, rated for 500 amps, the center point will be for the load and 6 outer points for the feed, should be out sometime next year.

[@EpiclyReckless]

Thanks for this. What if you added a couple inches to the battery 1 cables? Would that even it out even more?

[@rjw8316]

Nice video, well done. However I have a question, in the busbar configuration could I further reduce the current differences by adjusting the cable lengths for two of the batteries, say battery 1 and 2, to take into account the current path length through the busbar?

[@panospapadimitriou3498]

if you make a round busbar you can make t even better but you need a super beautiful terminal kind to go in center of the round busbars!!!! would love to se terminals for equal distribution !! kEEP the good work even half plannet away i love get educated and entertained from your videos!!! greetings from greece

[@Foxfried]

1 terminal won't be enough, they should make one with like 3 grouped together so you can feed power from solar charger, inverter, and alternator. a Circle with 3 botls in middle and 5-6 bolts around it.

[@3DLasers]

​@@FoxfriedI agree with you completely. Separate bus bars going into the main bus bars ? See my comments for some more thoughts on the matter. We'll figure something out here... 😃

[@panospapadimitriou3498]

BTW this shows some of the inside big batteries cells and why when full loaded the cells voltage drifts away and needs balancing!!! never forget cells are independent batteries in series and some of them are in center and others act as poles!!! !!!! made my run and install the active balancer to my pack

[@defsounds1097]

That first battery taking the load more than the others . I hook up the power to one of my battery's and the ground on the other to keep the current and load the same . I do the same with Power Inverter too

[@zebiklawi-hf1dr]

Broooo this is what i searched for! But i really want to DIY the barries with eve prismatic cells.

[@ForgeAheadwithMike]

How do we calculate the wire size for interconnects?

[@tiborchren]

Make triangular shaped bass bars where all connection points from all batteries will have approximately the same distance to the two connections for the solar charger and for the inverter on the opposite corner.

[@marcusmobley5411]

I really want to buy US made. I like ur batteries, but need a nice % off inspiration. All your competitors are doing it. Help us shop US confidently! Thanks!!

[@3DLasers]

A custom made circular bus bar ? A big flat washer with battery lug holes on the outside and a big hole in the middle for the input/output ? But with just a standard bus bar mount the two anode/cathode wires of the four on top of each other with the charger/load wires in the middle ?...🌩 ⚡️

[@Tkdmaster1991]

So would it be fair to assume that for a 2 battery setup, probly best to go with a piggy back setup with positive and negative going off different batteries?

[@KoreanTacoKing]

Nice vid, most people will already know about the wiring, I think you just wanted to show off the app 😁

[@sfkenergy]

😊

[@allensaelee6707]

Ok so will AGM lead be okay like the first set up? For two batteries? My boat has 2 battery system. Factory wired it parallel but battery (1 ) & (2) are 5 ft away from each other. The load is plugged into battery 1 like your first set up. Battery (2) is 5 ft away located in the back of the boat with just the Pos & Neg cable ran to it from battery 1 😅. Neg to neg pos to pos. Long cable. Should i just add a bus bar to it at this point so it pulls from each end? Draining & charging it equally as 1?

[@sfkenergy]

AGM will charge each other much better in parallel because they have a more sloped charge curve. But if possible use option 2. 1 should only be used if you are drawing low amps (under 10).

[@andrewski6563]

Stack the terminals instead of bus bar?

[@scottsheen6224]

What size are you cables?

[@tomp1193]

Could you have the cable for the inverter in the middle of the three cables on the busbar coming from the batteries? In other words could you connect the inverter to the middle lug on the busbar? Pause at 10:50 on the video

[@sfkenergy]

Yes that would make it a bit better but I think as long as the amp difference is under 10 amps it should balance out easily when you fully charge. The main goal is to avoid the large amp differences of 30+ and as long as you do this you should be good to go.

[@tomp1193]

@@sfkenergy Its just something i noticed in the video. I seen other videos where there was more than four batteries and the cables from the batteries were taken from the middle of the bank to the inverter. Unfortunately comments were disabled in the videos I saw. I wonder why?

[@Entity005]

Question. i got hold of 57 free batteries of 6volt 4,5Ah NiMH type of batterys .. Thats a lot of batteries.. i wish to make a giant powerbank in parallel connection .. Is there something i have to remeber? ... do i need thicker cables then the ones that already are on the batteries? how is it when i charge that many batteries in parallell ? do i need a super charger? or just use a normal charger that will just take much longer time? I also got a hold on 43 of 4 cells NiCd batteries with a voltage of 4,8 and they have 4,5Ah -- planned to make a 2nd powerpack with those. All batteries are only 3 years old and they are fully functional.. they had to be replaced because of strict rules on batteries that feed emergency light on ship .. they get replaced every 3 years even the law say 5 years.. guess shipping company just want to make sure their ok .. they have been maintain charged trough the years they been active.. and they only sometimes get used on test of the emergency light onboard.

[@gw877]

What would happen if you tapped off the middle battery.

[@henvan8737]

For best balanced battery output move the negative cable to the first battery terminal.

[@sfkenergy]

This would not make any difference as the third battery is wired the same way you could say in this setup that the order of the batteries are 3,2,1. Thanks

[@theeverything4036]

@@sfkenergy Have you ever heard current sharing and also internal resistance from the battery itself this would make significantly affects the performance. The 3rd battery would probably the first be charged up and also the first one to take the discharge.

[@inv1s_-]

I'm completely stumped as to why no one is commenting on wire Guage. I'm seeing all kinds of wire used across the internet and no one seems to care but people say it's important... but leave it out of every tutorial. I have 3 12v 200ah batteries to be run in parallel. I was just going run a bolt and nut through the 3 red to the red trunk, and the 3 black to the black trunk. Wouldn't this be better than a bar? I'm stuck on wire size... I'm also stuck on, do i need a fuse and what size to my 3000w inverter. I have a bunch of 8awg and some 4/0. Was going to 8awg the bank and 4/0 the trunk, with a 100a fuse, although i might up it to 200a. Thoughts? In case anyone cares: 2 x 60v 7ish amp solar panels, 300w? To controller run in parallel. So 60v 15a for 600 watts. To meet 100/50 mppt. 3 x 12v 200ah sla bats run in parallel(haven't done this yet, but planning to) on 8 awg wire to stud/ trunk. Trunk would be a fused 4/0 to inverter. All lines would be as close to same length respective to their run. Although I feel like a fuse would mess up one leg on the trunk... something else i don't see anyone addressing. Any help appreciated

[@jimduke5545]

You could have done even (pun intended) better had you wired the busbars [1|2|3|inverter] and [3|2|1|inverter]. This gives bats 3 and 1 the same resistance and bat 2 should be pretty close, if not the same (depends on whether the busbar studs are equally spaced). In this wiring config, all the busbar distances (and resistances) should be the same.

[@dustydawson8977]

Ty I 100% agree,they will be even closer balance,it's that one last step overlooked,even those his load is close enough,it can still be better

[@jimduke5545]

@@dustydawson8977 the only time I have seen any real difference is under really heavy loads or charging. It’s all probably in the margin of error in the clamp meter. My four batts in parallel stay balanced well, though and it was 5 mins to put the wires in the better (theoretical) order.

[@abtechgroup]

The one flaw in your setup is you should have fusing to each battery either at the battery or the busbar connection. Fuse rating at 150% of anticipated load. This prevents failure due to one of the batteries internally shorting and the other batteries delivering 10XC (C = battery capacity) current!! In your setup 60 to 80 amp fuses would be suggested.....

[@sfkenergy]

Thanks for your reply, this was meant to be a demonstration real world installs will use breakers and or fuses as needed. SFK batteries have internal shunts and can monitor amps which means they can be set to disable output at a definable output by the user in the app as well.

[@abtechgroup]

Oh thats a cool feature! I am considering replacing my lead acids in a sailboat and lithium certainly seems the way to go.

[@scrypturefx3077]

Which pole of the battery ought to be fused

[@randyk2904]

Impressive. But where is the charger connected?

[@zugmeister314]

He connected it (via clamps) to the terminals sticking off the front of the inverter. The charger is the little black box on the right, the inverter is the larger blue one underneath the charger.

[@brianrhodebeck6465]

I was told that everything goes to One positive bus and 1 negative BusAnd everything is distributed charging equally. In a parallel configuration

[@zugmeister314]

That would be mostly correct. The "mostly" qualification is because electricity always tries to take the shortest path to complete the circuit. Because the load wires (going to the inverter) are on one end of the bus bar the battery connected closest to that end is going to have a slightly heavier load due to its location. In another post here the guy who made the video says he's looking at making a circular bus "bar" (bus wheel?) so you can have a centrally located load / charge cable with the ones going to the battery terminals equidistant.

[@jmcasler1512]

Dangerous video. Where's the fuse?

[@zugmeister314]

It's a demonstration. You need a beer and some pizza!

[@3DLasers]

​@@zugmeister314But we like watching things that blow up... 💣

[@RGD-Repairs]

When batteries are wired in parallel.... You should connect the Positive to one, Like in this video, the 3rd battery..... But then the negative should be connected to the first battery (on the far left)....... Inverted connected directly to one battery like this, Forces that 1 battery to take the power draw, and then for the other 2 batteries to keep up with the demand... Connecting negative to first battery, and positive to the 3rd battery.. Will share the load equally between the 3 batteries, when the inverted demands a load..... (i install home, and off-grid solar systems for a living.. This has been thoroughly tested and proven to be more effective, stopping 1 battery from premature cell wear due to load draws)

[@brushbristlepressurewashin4258]

hello, do you mind illustrating ?

[@zugmeister314]

I think you just described his second (better) setup. It shared the load much better between the batteries on either end but the middle one was not directly loaded.

[@MichaelMascari-jh9yr]

You are confusing people with this video

[@armelpeel]

Ok this must be some kind of prop setup with non-live batteries because you touched an exposed connected busbar SEVERAL TIMES. There are no MRBF terminal fuses in place which means you would have been ELECTROCUTED AND KILLED had those been live batteries and not apparently props. I ask that you TAKE DOWN and REVISE this video because anyone following your "Best Parallel Wiring Setups" and touching live busbars WOULD HAVE BEEN KILLED. You obviously have NO KNOWLEDGE of what you are doing, or you are BLATENTLY TRYING TO KILL the unaware. Either way this problem needs to be addressed immediately.

[@Foxfried]

😆death by 12 volts!

[@sfkenergy]

These are live batteries, 13.0v is not enough to do what you claim. 48v or larger is where it starts to become an issue.

[@armelpeel]

@@sfkenergy Not only are you WRONG, you are DEAD WRONG. Dude you are an actor and you dont want to betray your role or whatever. A guy standing in front of a camera with props and I understand. But if you do that in REAL LIFE, with REAL BATTERIES, you WILL BE KILLED. YOU WILL DIE from this. If you use MRBF terminal fuses on the positive of each battery, you MIGHT live. If you use a shunt with a fuse on it, like the Victron Lynx Shunt, the fuse will blow and you MIGHT live. Dude you are DEAD WRONG about this and anybody reading this please take note. NEVER ONE TIME TOUCH A BUSBAR. THERE IS A VERY HIGH CHANCE YOU WILL BE KILLED. High volts will kill, and high amps will ALSO kill. You are using 3 high amp lithium batteries with no fuses. YOU WILL CERTAINLY BE KILLED. DONT TRY THIS, DONT ATTEMPT THIS, YOU ARE IN MORTAL DANGER.

[@jeremytam8219]

Youd need to touch both exposed bus bars at the same time to complete a circuit and be electrocuted. And its 13v you wont even know. Not an educated comment

[@markpirola8152]

Most cars are grounded and at a nominal 12-13 volts. Harm is possible if you are soaked to the bone say by a rainstorm and touch the 12 volts with an open wound on your body. In short pun intended, it is the relatively high and dry body skin resistance that protects you and your heart from electric shock damage. Penetrate the skin barrier, then depending on the path across your heart … just don’t !