I've used 4 golf cart batteries as my house bank for the past few years with much success. I just had a thought that maybe it would be a good idea to rearrange them so the current flow doesn't remain the same. Kind of like rotating the tires on your car for even wear. My thought is if current flows through the batteries in the same pattern time after time, the battery in a certain position would degrade at a different rate than the others. Maybe moving them around will "exercise" them and keep them at full potential. Any EE's out there with any thoughts if this really matters would be helpful :clap
Thanks!
[added to wiring to title - Stu]
Roc, if you've done it this way, no need to change anything.
Yup..that's what I did
Disclaimer....I'm not an EE. I think that if the specific gravity of each cell (hydrometer check) checks evenly. The charging is going well.
I'm far from being an EE!!
If the batterys (6v ) are in series the flow of electrons remains the same even if you place battery 2 first in line !!
A hydrometer check is necessay on any flooded battery. When I had flooded batteries the hydrometer reading told me the "health" of each cell.
Quote from: Stu Jackson on September 26, 2012, 08:35:45 AM
Roc, if you've done it this way, no need to change anything.
Not a big fan of the method on the right as the neg can take a short cut. I prefer to separately parallel the banks then pull off opposite ends.
Couple different orientations:
(http://www.pbase.com/mainecruising/image/146307339.jpg)
(http://www.pbase.com/mainecruising/image/146307338.jpg)
Maine Sail....yes, yes!! your diagram is exactly the way mine are wired; the + and - are pulled off opposite ends. Stu's diagram doesn't really show that, but overall, I said mine was wired like that picture. But your picture is exactly the way I did it......so...if the current is pulled from opposite ends, there is no need to "rotate" the batteries to change the flow? Just a thought that came up that made me curious.
Quote from: Ron Hill on September 26, 2012, 05:58:03 PM
Stu : As I mentioned I'm not an electrical whiz, but your 12v diagram (on the left) is giving a but more than 12 volts - me thinks!
Actually the diagram on the left shows 12V batts in parallel but NOT how they should be wired to remain in decent balance. That is exactly how NOT to wire them in parallel to keep them balanced.
This is how to wire parallel batteries to help keep them balanced.
(http://www.pbase.com/mainecruising/image/139681255.jpg)
This is exactly how NOT to wire parallel batteries..
(http://www.pbase.com/mainecruising/image/139681324.jpg)
Are we learning something now? :D I spent a half an hour looking for Maine Sail's sketch, couldn't find it and posted that one. Glad to get it right, finally.
I'd love to see pics of any 4 costco 6v battery setups with seperate starter battery. I'm getting ready to tackle this project and want to do a clean install.
Here's one we did on a friend's C34 about ten years ago. Don't know if it's wired right, based on the above. :D
Try the Tech wiki, I recall many more.
Where you put your reserve bank is up to you.
Also this:
http://www.smartgauge.co.uk/batt_con.html
Mine are similar to the picture above. Slid as far stbd as they will go. That leaves room on the center wall for my ACR and a couple fuse blocks for the battery charger leads. My starting battery is under the aft berth. To increase storage I had previously installed a fore/aft 2x4 just stbd of the large opening into the shaft area to keep things from sliding into the shaft. I fastened my new battery case to the 2x4. Added a new battery switch on the aft end of the walkway to the aft berth. Positive line from the battery goes through the switch to the starter, neg direct to the engine. Charging is via the ACR for both alternator and battery charger, wire is run across through the head, then under the floor to the battery compt. I can do pictures, but won't be to the boat until Oct 20.
Quote from: Stu Jackson on September 27, 2012, 08:04:51 PM
Here's one we did on a friend's C34 about ten years ago. Don't know if it's wired right, based on the above. :D
Try the Tech wiki, I recall many more.
Where you put your reserve bank is up to you.
Stu,
For loads and charge sources only two terminals on any bank should ever be used (temp sensors are the only exception). If you need places to put the neg's or pos for loads and charge sources bus bars can be used to get things off the bank posts. That bank looks like loads a charge sources were connected to what ever was closest and that can lead to a bank that gets itself out of balance...
This one may make more sense..
(http://www.pbase.com/mainecruising/image/129973312.jpg)
Here is how I did mine with 4 golf carts and a separate starting battery. I wanted to keep things original as possible. will take a picture of the installation on the boat later today so you can see how they all fit.
Jack
Here is a picture of the golf cart battery installation on our 2001. I had to increase the size of the battery boxes by cutting them in half and fiberglassing them back together, about a 1/2" increase in length. There was room to screw them back down to the wood floor plate. The single 2x4 wood hold down for the former 4D's was replaced with 2 - 1/2" threaded rods that are covered with clear plastic tubing. A new floor plate was added for the 12 volt starting battery, which was installed in a standard auto battery box, all held down with a tie strap. The buss bars are located under the lip of the seat on the back of the sink cabinet. I simply reused the cables coming from the battery switch to the new bus bars and then added the new cables between batteries as needed.
The new installation has worked well so far. We have been on the hook for up to 4 days before a recharge and the larger bank never was lower than about 85%. Our refrigeration is our only big draw as we do not run a TV or computer. Minimal reading lights as well as a LED anchor light is about all we use at night.
Jack
Update. I put in golf cart batteries in 2004 as in the diagram by "mainsail". This was the same diagram I received from John Gardiner(Seventh Heaven) back in 2004. Followed his ideas about the size of wiring etc. This past summer was the 7th season on the batteries. We live aboard for 3 months in the North Channel. I do have a 1000 Honda as a back up. Very pleased with the setup. I also took Stu's advice to keep things simple.
Paul
I checked my wiring and the picture I had in my mind was incorrect. I need to switch either the pos or neg lead to an opposite corner, so the batteies are balanced, as Mainesail suggests. However, I don't think either wire is long enough to make the trip. I can either move the pos or neg cable. If I put a buss bar with a new short cable to make the run, would it matter if I do it for the pos vs. neg cable? I was thinking about using the buss bar to connect the neg cable, then run a short cable to the opposite corner for balancing. Don't know if it really matters.
Thanks....
Roc : If you have the space a buss bar for the terminal should work.
I have a similiar problem with the negative wire balance problem, but only from the alternator. The shore power battery charge is OK so the Honda charging is also OK. I just might lengthen the alternator negative wire or not do anything as most of the longer time charging/drawing is OK.
A thought
Roc, consider it like holding it up a mirror - same thing, right? Not an issue.
Roc, I installed a buss bar for both the pos and negative (see my posts above), that way I did not have to do anything to any of the wiring already coming to the battery compartment. I only needed short cables connecting the batteries, which you have to have anyway, plus two other short runs form the opposite terminals to the buss bars. The negative buss is a bar with 4 terminals on it, but the pos is a simple post as there are fewer cables to it.
Jack
Would this buss bar be sufficient, or is a more costly item needed.
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=17180&catalogId=10001&langId=-1&storeId=11151&storeNum=50523&subdeptNum=50549&classNum=50553
Roc : I've made my own buss bar/common trminal out of a piece of oak and and inbedded nut and bolt. A thought
Roc, that is the buss bar I used. Don't think I would ever exceed the rated capacity.
Jack
I plan on taking the neg wires, that are now split between the two neg battery posts, and compile them to a buss bar so I can balance the battery bank like Mainesail suggests. Right now, I have the neg wires from the battery charger, reserve battery, windlass, engine ground (and I think the last is from the water heater). These will go on the buss bar, then one big wire from the buss bar will go to the opposite neg post on the battery (opposite corner from the pos post, like the diagram). I've heard that the rule of thumb is to take the gang of wires, wrap them up, and the thickness of those wires together will dictate the gauge of the ONE wire needed to carry the load. If you gang all these wires, I'm not sure that even a 1/0 wire is big enough. I'm thinking of using maybe two smaller wires (2 wires of 1/0) that go to the buss bar to the one neg battery post. Those two wires should certainly reduce any resistance from the gang on the buss bar. Would that be kosher?
Roc, do you have a DC water heater?
Quote from: Roc on October 23, 2012, 01:09:35 PM
I plan on taking the neg wires, that are now split between the two neg battery posts, and compile them to a buss bar so I can balance the battery bank like Mainesail suggests. Right now, I have the neg wires from the battery charger, reserve battery, windlass, engine ground (and I think the last is from the water heater). These will go on the buss bar, then one big wire from the buss bar will go to the opposite neg post on the battery (opposite corner from the pos post, like the diagram). I've heard that the rule of thumb is to take the gang of wires, wrap them up, and the thickness of those wires together will dictate the gauge of the ONE wire needed to carry the load. If you gang all these wires, I'm not sure that even a 1/0 wire is big enough. I'm thinking of using maybe two smaller wires (2 wires of 1/0) that go to the buss bar to the one neg battery post. Those two wires should certainly reduce any resistance from the gang on the buss bar. Would that be kosher?
Roc,
Don't know where you heard that rule of thumb but that is not how it is done. 1/0 wire should be more than adequate for your boat. Your highest load will be the starter, then the windlass and then perhaps the inverter. You'll never have all going at once because if you did the inverter would drop out on low voltage.. Early C-34's shipped from the factory with 4GA, which is undersized, but it still "works" in the most basic sense. 1/0 works a LOT better......
Mainesail...thanks for the advice. I'll go with the 1/0 wire....By the way, I appreciate your input to this site. It's always very informative.
Fredrick...no, I don't have a DC waterheater. I was pictureing all the neg connections on my battery in my mind and I thought of one extra that I couldn't figure out where it was from....just doing things from memory in a hastey fashion.... I have an AC water heater, OEM from the factory.
Quote from: Roc on October 24, 2012, 04:08:51 AM
I was pictureing all the neg connections on my battery in my mind and I thought of one extra that I couldn't figure out where it was from....just doing things from memory in a hastey fashion.... I have an AC water heater, OEM from the factory.
Roc, it could be the negative from the electrical (distribution) panel.
Thanks for the diagrams, they make it easy to understand. Where would the alternator be wired into this circuit? Also, where would an inverter be on this circuit? Thanks!
I re-positioned the wires so they now balance the batteries like Mainesail suggests. I added a neg. buss bar and ran one neg. wire to the opposite side as the picture suggests. The question I have is does it really matter which neg. post the battery temp sensor is mounted? On one neg. post, I have the large wire leading to the buss bar, along with the jumper wire. On the other neg. post, I have only the other end of the jumper wire. There is no room to put the temp sensor on the wire which has the two wires connected, so I can only fit it on the neg. post that has the one jumper wire. Should the temp sensor be mounted on the post that "balances" the batt bank (shown as GND Yes)? Or can it be on the other post (where Mainesail marked as GRN No)? Interested in any thoughts on this...
Thanks!
We have the 4 golf cart batteries, wired per Mainesail's diagram. A related question that we have asked before, but have not received an answer, or at least one I can remember. Other than acting as a backup, is a starting battery needed for our engine size? We do have a Honda 1000 for emergency charging. Thanks for any insights!
Steve, no. It IS just as a backup in case your house bank dies for any reason: overuse overnight, catastrophic failure, that sort of thing. Both Maine Sail and I use the house bank to start the engine all the time, regularly check the reserve bank (by voltage and using it occasionally) and have had success for over 15 years with this setup.
Quote from: Stephen Butler on May 19, 2013, 03:44:55 AM
We have the 4 golf cart batteries, wired per Mainesail's diagram. A related question that we have asked before, but have not received an answer, or at least one I can remember. Other than acting as a backup, is a starting battery needed for our engine size? We do have a Honda 1000 for emergency charging. Thanks for any insights!
No you don't have to, it is a personal choice. For the cost of a "reserve" bank it is never a bad idea.
Just yesterday I was working on a J-42 that currently has no emergency bank, just a house bank.
I was there trouble shooting his failed Link 2000R. The "R" means it was also his alternator regulator. He lives on a mooring.
Had he not been the attentive owner that he is he could have easily killed the house bank and not noticed. As it was the expensive Lifelines were at 11.2V when I got there....
There are MANY boats out there without adequate safe guards such as battery monitors or additional volt meters in addition to a battery monitor. Lucky for this owner his J-Boat has multiple voltage displays in addition to the Link 2000R that completely failed. he was able to notice that the voltage was steadily dropping and modified his use accordingly.
Had he only had the Link 2000R he may have "assumed" the display just went dead and eventually been left dead in the water because he also had no alternator... In his case everything the Link 2000R controlled was inoperable from the inverter/charger to the alternator regulator to the battery monitor..
I will be installing a "reserve bank" for him, as well as new regulator, battery monitor and I/C remote & a small solar array in the next three weeks.... He learned his lesson and now wants a suitably big reserve bank of two group 31's....
Thank you Stu and MaineSail. Much appreciate the response.
I re-positioned the wires so they now balance the batteries like Mainesail suggests. I added a neg. buss bar and ran one neg. wire to the opposite side as the picture suggests. The question I have is does it really matter which neg. post the battery temp sensor is mounted? On one neg. post, I have the large wire leading to the buss bar, along with the jumper wire. On the other neg. post, I have only the other end of the jumper wire. There is no room to put the temp sensor on the wire which has the two wires connected, so I can only fit it on the neg. post that has the one jumper wire. Should the temp sensor be mounted on the post that "balances" the batt bank (shown as GND Yes)? Or can it be on the other post (where Mainesail marked as GRN No)? Interested in any thoughts on this...
I posted this question the other day. Any thoughts about it making any difference which post the battery temp. sensor is mounted? Read original post above.
Thanks
Roc-
my house bank is wired as mainsail suggests, I have a Alternator charging wire connected direct to the house bank, it is on the same terminal as the positive wire to the electrical panel. Is that where it should be? My bilge switch is also connected there, as is the positive connection to my vitron battery monitor Thank you
Bob, yes, you're right.
Place it on which ever battery has more potential for getting the warmest... If one is closer to a water heater or engine or sunny side of the boat at a dock then put it on that battery..
Thanks Mainesail, I appreciate your advice.
Quote from: mainesail on September 26, 2012, 06:12:35 PM
This is how to wire parallel batteries to help keep them balanced.
(http://www.pbase.com/mainecruising/image/139681255.jpg)
This is exactly how NOT to wire parallel batteries..
(http://www.pbase.com/mainecruising/image/139681324.jpg)
It's an OLD post, but a current (ugh! :rolling) question, so I tacked onto the same thread.
Rod (or J? anyone?) -- I believe your assertion that method 1 is best, but.... WHY? :think I mean how (phenomenon?) does B1 become unbalanced compared to B4, unless there is serious V loss across the cables and/or terminal connections (improper size or installation)?
I in each (B1, B2, B3, B4) should depend on the resistance, ass/u/ming that V is ~the same at each circuit node (very low resistance in cables and terminals.) From experience, how much could the B1 > B4 imbalance amount to? 10%, 20%
If V loss is the cause, would it be "best" to charge something like this?:
(https://www.impactbattery.com/realblog/wp-content/uploads/2016/10/Charging-Perfectly-Balanced-2-1024x594.jpg)
There are multiple methods that create better balance in a parallel wired system than the end connection scheme we see all to often. The bottom one you show is excellent, better than the one I and most battery manufacturers show, but if I had a dime for every-time I saw it messed up in execution, well...
The other better balance method would be the star config where each battery has an equal length cable going to a pos & neg bus. The problem here is having the exact same resistance in each cable. The drawing I show is a big improvement over an end connection, and more importantly very simple to execute, but you can do better, if it is done correctly.
For series 6V batteries there is also the "box" wiring scheme but you also don't see me recommending that one much either as I see it screwed up and misunderstood far too often as well.
(https://marinehowto.com/wp-content/uploads/2015/04/14-What-Is-A-Deep-Cycle-Battery.jpg)
But what would EnerSys know about batteries...... :thumb:
Quote = Odyssey/Enersys:
"Parallel Connections:
It is common to have batteries connected in parallel to
achieve a desired amp-hour capacity. This is done by
connecting all the positives to each other and all the
negatives to each other.
Typically the positive and negative leads to the load
are taken from the same battery; usually the leads from
the first battery are used. This is not a good practice.
Instead, a better technique to connect the load is to take
the positive lead from one end of the pack (the first or last
battery) and the negative lead from the other end of the pack.
The two methods are illustrated above. Solid lines and
arrows indicate positive terminals and leads; broken lines
and arrows indicate negative terminals and leads.
In both illustrations, the positive leads are connected to
each other; similarly the negative leads are connected to
each other. The only difference is that in the first illustration
the positive and negative leads to the load come from the
first and last batteries. In the second case, both leads to
the load are tapped from the same battery.
The first schematic is recommended whenever batteries
are hooked up in parallel to increase battery capacity.
With this wiring, all batteries are forced to share both charge
and discharge currents. In contrast, a closer inspection
of the second schematic shows that it is possible for only
the battery whose terminals are tapped to support the load.
Implementing the first schematic eliminates this possibility
and is therefore a better one."
End Quote
Thanks Rod!
That blurb from Enersys is another yule log on the fire supporting the correct hookup. :thumb: :santa
So differing resistances (cables, terminals, batteries) is the bane of equal charging -- but it begs 3 question --
1. As B1 fully charges, resistance drops it out (then B2, and so on)-- so why don't all (eventually) charge as well? Is it as simple as the engine typically doesn't charge long enough for the V across all posts to fully equalize, or is there something else going on? (I'm talking OEM/Moto 55 amp/wet cells here, not suped-up charging/ACR/AGM/etc.)
2. Mixing battery age, types, capacity in a bank is verboten. So why is it Ok to charge the house and a "start/reserve" using BOTH on the selector switch? It's just one big parallel bank with one of unmatched type, age, and capacity (and probably different V loss on the cables.)
3. If the cables were infinitely large/terminals no resistance (frictionless pulley), unbalanced charging would not occur?
-k
Quote from: KWKloeber on December 10, 2018, 10:41:14 AM
Thanks Rod!
That blurb from Enersys is another yule log on the fire supporting the correct hookup. :thumb: :santa
So differing resistances (cables, terminals, batteries) is the bane of equal charging -- but it begs 3 question --
1. As B1 fully charges, resistance drops it out (then B2, and so on)-- so why don't all (eventually) charge as well? Is it as simple as the engine typically doesn't charge long enough for the V across all posts to fully equalize, or is there something else going on? (I'm talking OEM/Moto 55 amp/wet cells here, not suped-up charging/ACR/AGM/etc.)
2. Mixing battery age, types, capacity in a bank is verboten. So why is it Ok to charge the house and a "start/reserve" using BOTH on the selector switch? It's just one big parallel bank with one of unmatched type, age, and capacity (and probably different V loss on the cables.)
3. If the cables were infinitely large/terminals no resistance (frictionless pulley), unbalanced charging would not occur?
-k
It all comes down to slight variances in voltage, under load or charge, meaning one battery works less hard (the one furthest away) or one works harder than the others (the one with the connections). I know Chris Gibson of Smartgauge did a whole write up on it but I don't recall where that is. All I need to know is that wiring for balanced banks works better than not wiring for balance. I know this from countless Ah capacity tests of banks wired using correct and incorrect methods. After a couple of years the differences are certainly measurable and consistently repeat themselves over and over.
It's not just EnerSys who show opposite end wiring of a parallel bank, it's pretty much every battery maker I know of...
:thumb: thank you Rod. I'll search 'round for that write up.
Ken
Rod maybe this is the writeup? I att'd a copy for anyone's use and will put it in the techwiki.
[ed]
http://c34.org/wiki/index.php?title=Electrical#Batteries