One of the only explanations using three batteries in parallel, which is just what I needed...

Thanks for making this video, I learned the hard way on connecting the battery (damaged four new battery).

Jerry That was the best explanation of battery banks that I have ever heard And I have been around batteries and chargers for most of my career

Best explanation on multiple battery connections I have ever seen, great job. The solar vs. vehicle alternator charging was a huge eye opener! Thank you for that...

Great tests!! Keep it going. Put an amp meter between your alternator and your battery bank, and each charge controller. Also read about internal resistance of batteries. You are doing some great stuff here! Fun learning experience to be had. A shunt on the negative terminal of the battery bank will help you greatly. A watt meter between the alternator and your battery bank will be extremely useful too. Keep going! You are doing great.

Well, Lynn, us nerds were on the edge of our seats listening to professor clausen. 😀

I really like the method of balanced wiring you showed at the end. I tried the "sum of resistances" method on many different number of parallel battery configurations and it worked. Great information!

HI JERRY. I am trying to learn as much as I can about solar charging and battery banks. It appear to me that you are quite well informed on this. Thanks for sharing what you know.

Thank you sir, this helped me alot. My batteries wasn't lasting like the first few weeks I bought it.

Not boring haha! Fascinating!!

Hey Jerry and Lynn, I truly think Lynn needs more air time. She cracks me up asking if this is TRASH!!! This is my daily comment to my husband. Hope you two have safe travels and get some more battery life. My smart Husband is a Corrosion Specialist ( 1 of 3 in the state of Oklahoma) and I can’t wait to show him this video. He’s all the time talking about batteries trying to educate people on corrosion. Never knew batteries where so interesting. 😂

Thank you sir for the video. Like others I had my 3 batteries wrong. Your video explains it perfectly now they are hooked up right. Before it seemed to charge fast, now connected this way, taking longer to charge since all 3 are charging together. You and the wife stay safe, and thanks again.

Don Amigo JC, your 12V battery presentation is really *BRILLIANT* just as well as your conclusion regarding a bank performing as its weakest battery. You're a wise man who knows batteries are all about the internal resistance and line resistance that drop voltage under load. U = R x I (... aka. "Ohm's law") In PARALLEL voltage is equal but CURRENT IS DIFFERENT based on internal resistance. In SERIE the current is common and the voltage is an addition. Now on the useage path, I see from the picture of your pannel you have a dual diode insulator so you can't run down your engine battery while blasting cumbias in the coach with Lynn. The down side being that silicon diodes semiconductor junctions drop/eat 0.6v Ea. verdad? Best friend of Lead-Acid chemistry being a cell equalization float charge and worst enemy is deep discharge sulfation or overcharge evaporation, claro? Up North... the latest rage are the big $200 AGM batteries by Varta: the juice is replaced by a GEL for nearly zero evap. 🤘 As always love all your wise tales and wisdom on life - ¡Gracias! 👍

Great Information...

Very interesting topic...! I had never really thought about it before. Some good information...! Thanks for sharing this with us. Tell Lynn that I want a life full of coloring and singing. Have a great day and be blessed. Btw... I look forward to seeing what your testing proves.

Now I know more about "charge controllers" than I want, but hearing your lectures on the subject makes my day. Sorta. But I like you anyway.

Thank you so much. Received and understood.

Simple but thorough explanation. Thanks. I now know what the prob is with my lithium battery setup. In an attempt to keep the cables going to the inverter as short as possible, I just connect the pos and neg cables to the closest battery but for 3 yrs it seemed that I had 100AH instead of 200AH and the discharge rate seemed high for a 200ah Bank. Thanks Jerry. I now have some rewording to do lol

Awesome job 👍

Okay, gotta be honest and say if we were on the "edge" of our seats, it is only because we were about to drop off into a total stupor :-) In order to remain on your good side, I shall gracefully claim that in my case it is because I am about to turn 70, do not own or operate a Cummins diesel-based RV and may therefore be somewhat lacking in charge controller passion and the stamina to properly benefit from such an erudite scientific presentation. However, finally the good Lord intervened and Lynn came to the rescue with as Gil C. aptly noted a bust-up-laughing "Is this trash? comment asked with such pure innocence that I could barely contain myself as I was just dying to see your facial reaction. And then she indeed provided the the piece de resistance in the form of a short chorus of "Whoop De Doo" to save the day! Jerry, hold onto that gal, she's definitely a keeper! :-)

GREAT VIDEO , Your are right they have the words but dont have the music. My explanation for the two charge controllers hooked up in parallel is that one charge controller is at higher voltage then the other. theoretically if two sources have same voltage they would charge equally. All the load is taken by the source with higher voltage.

funny, i've been asking myself the same exact question for months/years ! who would win the battle if you hocked many source of power together... btw, loved the intervention of your co pilot at the end ;)

I connected the system incorrectly....I found the right way by watching the video...nice sharing thank you..

You are correct my friend and if you are using 4 batteries you got to hook it another way to balance charge and discharge. Equally

Thank you so very much for your clear and lucid explanation!

I'm not a book geek just a guy that has lived off grid for 26 years and found that books are written by people that don't live off grid and have no idea of what works and doesn't work. I'll say it, they have no clue and are wrong. You are right and a easier way of explaining it is each battery is concidered a cell in one big battery. Also not sure if you have a charger in your inverter but it to will shut down if the voltage is to high from the source. As far as charging while driving just add a battery isolated between the alternator and the pannels.

Hey Jerry, loved the video and I have found the same outcome on my own ventures... Which brings me to this next bit of info, I found a very interesting video when using 4 batteries in parallel, the charge should be given to the centre two batteries and the load taken as you have described... I found this info before watching your video and have not yet tested the information... However it is described as balanced charging, which I believe would benefit you greatly...

I'm a new subscriber and enjoy your videos, thanks for sharing your experiences.

I'm with Lynn..she's the cutest!!

Hi I’ve subscribed I’ve got 3 new battery’s to wire up to a car amp this weekend I can across your video so basically the power from alternator will go to furthest postive and the ground will go on the further away just like you drew up that correct

Thanks, Jerry. Enjoyed the lecture and comments. (Glad there wasn't a test this time.) Liz apparently agrees with Lynn's "whoop ti do" as she left a long time ago. Some people don't appreciate "genius" when they see it in action. Nicely explained. I think a trip to Gossips is in the near future. Let us know when you are ready!

Finally!! This is the video I needed!! Thank you very much.

I agree 100%. I wired two 110ah batteries on a 300watt solar system on my catamaran and it works great. I've currently modified the majority of my electrics and replaced my old solar charger for a victron mppt 100/15.👍🏿😎🌊⛵🏝️

Thanks a lot 👍👌

I am actually related by blood to mark twain. funny you mention him. So lets get into parallel battery strings: Internal resistance varies battery to battery and any parallel connection is a fault point, always. One will falter faster over time in a bank, and once it takes the "grunt work" of charging and discharging, it creates more heat, then cascade effect occurs till the battery fails. Internal resistance of battery can be higher than the resistance of a properly gauged wire. Depends on the wire type and size. Depends on the internal resistance of the battery. This is a fact that you can easily measure at home. Your diagram did not show all variables that can affect your "electron flow".

Lynn had me busting up. “Is this trash”.

18:32 Wow! never thought about that way, thank you so much. Subbed. All the best

Great Vid! However, at 20.00, you made the classic mistake, of showing that the power, discharges through the "POSITIVE" terminal. Wrong, it discharges through the "NEGATIVE" terminal. This, is contrary to what you would assume, I Know, but it is correct! Thanks, anyway.

I am I know these are solar expert but I am learning because I’m setting up an off grid system and am learning quickly how expensive it is. My best advice for you would be to isolate batteries banks. When you park and want to runoff of solar throw a switch that allows the batteries to feed into your inverter. While driving use the batteries that you would normally run for systems needed while driving down the road. Starting, radios, fridg, etc.

Love to see Lynn in your video's.

Nice video loved the tender moment at the end :)

Ok sounds good thank you going to chapala in Sunday will be thinking of you

finally someone agrees with me on battery hookup,from opposite corners thanks

Again, Lynn swoops in and saves another video!! ;) LOL. Congrats on 18K!

got a laugh from your wife at the end that was great LOL

Are you then rewiring to discharge the power from the batteries? Moving the pos. back to the other end with the neg.?

I know this video is old but some clarification needs to be added here. Electrons flow from negative to positive not the other way around. Second, a battery isolator was created long ago to offer such a solution to avoid draining / not charging a battery bank. Those who compete in car audio know this quite well. They have a battery isolator that allows them to play music for hours without draining their primary SLA battery so they can start the vehicle later. The very old and dumb battery isolator detects a defined threshold and disconnects the two battery systems from one another. While also allowing the alternator to recharge both once the vehicle has been started. Newer designs allow a person to define what voltage (high & low) to be set. Along with when the battery bank should be charged. This was created primarily because people were blowing their alternator as it could not generate enough power (current) to recharge the massive banks. In 2022 some of the latest battery isolators, charge controllers, and battery chargers incorporate BMS level monitoring as seen by everyone using LiFePO4 / similar battery systems. Lastly, the 90-10 rule for DOD for LiFePO4, low temperature charging, low / high voltage thresholds, and current draw are key elements of service life or the lack thereof. Any other wet cell technology from AGM, Flooded, etc offer for only 30-50% DOD regardless of what any maker claims even Trojan / Rolls.

Jerry: I now dub you my 'Favorite KZfaq Polymath' ! Bestowed with respect, sir... wear it with pride ;- ). Thanks for this deep-dive into helping others understand there are many configurations, and potential problems, with off-grid power systems. I've added this one to my bookmarked list. [You and Lynn together 😂... Burns and Allen? Mmmm, no. Lucy and Ricky? Mmmm, no. Groucho Marx and Margaret Dumont? Hmmm, getting closer... How about Doug and Carrie from 'King of Queens' ? 😀 ]

Love you

Thank you for making this

I recognize this is an older video, but your thoughts here about solar tricking your diesel alternator that the battery is charged sounds correct. You sound spot on with your theories. Good watch! Earned a subscriber!

Sounds like you have it figured out. Whaopteydo. 😱👊👍😎

Very helpful sir

Even my diesel truck from the manufacturer is wired wrong. They call the second battery the secondary battery because it doesn't contribute as much as the primary battery. All it does is boost. Well I just added a third and wired all three straight to the starter. lol Cranking speed is way up and start problems are gone. Now my accessory batteries are always wired with the diagonal wiring scheme as it can take a really long time to charge 6 batteries if they aren't due to the reasons you gave.

Helpful Video

Thanks for your vid...So, a newbie question...lets say you have 4 12V batts in series/parallel -- a 24V overall system. Now which posts do you connect charge/load to? My guess would be the (+) on one bank that was not used for series and the (-) on the other bank that was not used for series.

So thankful for this video. Please forgive if I am acting dense but if I am understanding correctly, a person could hook up more than three batteries in parallel in this configuration, without causing any further accumulation of damage to the battery. I'm sorry if you have discussed this in another video as this is the first of yours I have watched regarding this topic. Thank you

It's not fighting with the other charge controler. Numbers go up and down when you. First turn it on with or with the other Charge controler going on. The most takes time optimize the power it produces

Lv u sir....

Well sir, if I understand you correctly . When I connect to my inverter I should connect the positive cable to the third battery and then the negative to the first battery. Now when the battery's are being discharged by my inverter should I keep the negative cable the shortest because when discharging its the negative side that's asked to do the work.

Thanks! I'm trying to find an answer to connecting 5 lifep04 batteries in parrallel. Each one has a 150amp bms meaning it can output up to 150amps. I'm considering making independent cables all the same length for each battery that connects to a common positive and negative bus bar with a fuse inline for each one. But that's going to take 50 feet of 2awg instead of about 15 feet to do your method. That way every battery will hopefully stay at the same level. Or am I complicating things and wasting money? My other concern is if the bank of 5 batteries discharges all the way and only 1 or 2 batteries are trying to fulfill the 200 amp load to the inverter, if they are connected by your method will they be strained by depending on the dead battery next to them? I never want these to go to zero but as they're on a boat it will end up happening from time to time.

thankyou, very helpful

LOL - is this trash??? Love it!!!!

i love this video..

I have 3 AGM batteris in the "proper" set up that you show, but battery 1, that the charge cable is connected to, heats up considerably more than the others, and has actually ruined one recently. Ive seen this be called "unbalanced charge." from what ive seen, you would need to be the charge cable in the middle of the 3.

Jerry make Lynn laugh as much as you can , it helps by releasing the right hormones , be one step ahead of things for her to do nothing to hard , play back the musical memories it helps , life is hard sometimes and the road ahead becomes a lonely place , don't get into an argument , always change the subject to a funny one , not easy sometime , you have the memories that will help her .... good luck .

if i have 4 12V batteries and want to do a 24V system, is it better to hook them up into: 2 in series + 2 in series and those in paralel or 2 parallel + 2 parallel and those in series ? as allways there are folks that say the first is better and other say the latter is better ...

Let me say a couple of things that may or may not have any implications regarding your mental presentation. First, in the universe of atoms there are protons, neutrons and electrons. Protons are positively charged. Electrons are negatively charged. So, the negative pole is called the negative pole because it has a build up of negatively charged electrons waiting to let go at an instant's contact with a conductor. If that is accurate, then in batteries, the flow is always from the negative pole to the positive pole. Generally, the work load is somewhere between the negative and the positive pole. Which means you never want to hook up the negative pole first because when you hook up the positive pole, you will get a bite or spark from the massive flow of negative electrons from the negative pole going through your body perhaps to the positive pole or to a grounded surface. If you hook up the positive pole first, you are hooking up the "hole" into which the negative electron charge can let loose by touching the negative charge to the negative side of the battery. You give the force of the battery a place to go, namely the waiting positive "hole" rather than waiting to put you into a shock. In commence parlance, we think of a positive like a pile of stuff that we put into a negative hole. In electric circuits, the hold is the positive. It lacks the mojo juice. The electrons are stacked up at the electron pole, the negative pole. You are perfectly correct and helpful with your parallel example and suggestion. Just don't forget that the negative pole has the pile up of negatively charged electrons ready to take on the tasks you assign to them.

looks good.

I think it depends on which one is stronger. If solar is stronger st charging then other charger will back off as it just sees battery voltage rising and safety measures kick in and the charger only know the voltage is rising and thinks It needs to back so it DDT iesbt blow up the battery

Is this correct. Thank you, I'm trying to do this right. John

Using opposite ends, can I connect ten AGM 12V 100ah batteries in parallel, for my solar system battery bank? Note: using equal length 4/0 cable connectors, and equivalent new batteries. Thank you.

Jerry, just a thought would be to prioritize the controllers. Create a circuit that is monitoring each controller and isolate the others via contractors. Example if the engine is running that is number 1, if it’s not one of the solar chargers is number 2 etc. I don’t have the exact circuit in my mind without more thought. Just a direction to look at.

Lynn made me laugh out loud. Of course, I get the same reaction from my own wife, so it was nice to see that I am not the only one to experience the "commentary". About the multiple battery charging sources... My college major was in electronics, and I've designed many a circuit, so ... here is my two cents worth: If I was the design engineer of your solar chargers, I'd be waving my hands in the air and my heart would be racing. None of the charging methods are designed to be compatable with the other methods you are using. Each was designed to operate singularly. (Probably says so too, in the small print, under the legal disclaimer.) You are correct, in your conclusion that they intefere with one another. My suggestion: I noticed that you have two very nice Battery Selector Switches mounted on the Electrical Panel. These should be used to combine both the Starting Batteries and the Storage Batteries (deep cycle "house" batteries) in parallel connection while the engine is running and you are driving for an extended period of time. However, when you park the motorhome and shut the engine off, the Battery Selector Switches should be set to "isolate" the starting, and the house battery banks (taking them out of parallel connection) and only the house battery bank should be relied upon for interior lighting and other DC appliances. Note: The solar panel chargers should only be permitted to charge the house batteries WHEN they are isolated from the starting batteries. This will prevent competition between charging sources, and prevent other maladies from rearing their ugly heads at a later date (and no doubt, an inopportune time.) Example: If the designer of Solar Charge Controller A saw fit to dissipate excess charging current from the solar panels, by means of "dumping" the current through an internal power resistor, whenever Full Charge was sensed on the associated battery bank ... it might not take kindly to the 225 Amp engine alternator "cooking" the power resistor, due to the two battery banks remaining in parallel during drive time. No one can tell you definitively, if this, or any other situation exists, without studying the electronic schematics of the chargers in question, or at least having a phone chat with the manufacturers. That is my two cents worth. Sorry if it seemed like three cents, but I'm simply trying to help. Do what you will, with it. CTRL / ALT / DELETE doesn't cost anything. 😃 Best regards.

your example assumes all mirrored cables are the same size and length?

Great video at explaining. I have a question regarding the second example of connecting 3 batteries in parallel, if you connect charge source to opposite batteries do you then connect draw from the same terminals?

So should I discharge the same way I charge

Can I combine 2 sets of 4 batteries in parallel instead of one parallel set of 8 batteries

Greetings all ...how do I connect three 12v batteries in series but keep 24volts

So, I'm I correct in assuming it would be the SAME Wiring configuration, if you had 4, 5, or 6 etc., ? Please let me know. Thanks

I have always thought a good way to do it would be “it maybe wrong” is to have a bus bar and connect all the + and - to the +/- bus bars 🤔, I know it would take more wire. Looks to me though it would work even more even.

I know nothing of the solar side but yeah at first glance this seems simple but can be a headache so hopefully it's as easy as solar stopping alternator from giving batteries that little bit of charge to what we determine full is. Alternators main purpose really isn't to charge the batteries completely anyway. Yes in a car with 1 battery it will give it it's 1-2 volts. Even in that case it's kind of a phantom charge if that makes sense unless you drive awhile. Example when we dumb young people add amps for subs the battery is always dying no matter how much we drive. This is why we install a capacitor and in alot of cases have to get a bigger outputting alternator bc it will start using most of alternator main power and alternator seems to forget to give that battery it's very needed couple volts. Not sure if you ever tested how long batteries last when they are wired in something like an RV. Let's put it this way they knew what they were doing perfectly on the electric side in my opinion. So yeah I know I rambled on something you sound like you know 100% but hopefully it's the solar not letting it charge. Unless you added some electric pulling devices that are aftermarket and this issue just started happening randomly then I'm sure it's what you have already explained. Otherwise could be batteries or even alternator but those are easy fixes as well.

Love it

I have a simple setup for boon docking. Three deep cycle just as in your diagram. My question is for anyone here. So once I've connected in this balanced manner for charging configuration, would my inverter then also use the same positive and negative terminals or does it not matter?

You would think that a charging controller would analyze the sources and allow only the strongest to charge the system. If you turn off the key, then it goes back to solar charging. I'll be waiting for the next episode.

There's more than one way to heard some cats. On a serious note, very good tutorial. Thank you.

Hi JC in Guadalajara quick question can I use my ATM here and if so where do you suggest bank or any atm ??

Lynn:booooring 😂😂😂. I’m like her. I don’t know anything about batteries,solar panels or whatever was in your mind today 😂😂😂.

How many 12v battery can be parallel ?

Charge through the center battery brother

I had a similar problem when my start battery was full the alternator stopped charging so the house batteries would not change because it was detecting the start battery was full a auto electrical engineer fitted a device that switches the power from the start battery when full to the house batteries it was not that expensive £120 with labour

Lyn got him trash (bboorriinngg)

J C your diesel alt might not be putting out 100 percent might be long in tooth. 6 to 10 hours 250 to 300 amp alt everything should be glowing with charge. ✌👍🔧🔋

Its possible your alternator is failing

...hahaha...Yeah, Lynn, bor..ing.

Good electron flow summary diagram, except I was taught electrons have a minus charge and electrons flow from minus to positive. Not that it makes any difference in what you explained about resistance.. Let me throw this out. If you correctly had the charge circuity wired, but had a corroded battery terminal or two, what happens then? Seriously, you must maintain perfect battery connections with multiple battery systems so those pesky electrons don't get confused and go elsewhere :) Thumbs up! PS...No one has ever physically seen an electron, so it is all theory anyway!

Did you watch Will's new video on more than one charge controller?

I like your video, sounds like man stuff, being around woman stuff, Jose Alsniz

One will never know do one.

my 2 cents as a retired Master mechanic, I was told years ago that any ex-spurt can write a magazine article or a book. Just sayin'...