Page 1 of 2 12 LastLast
Results 1 to 20 of 36

Thread: Battery Bank Charging

  1. #1
    New member
    Join Date
    Sep 2008
    Posts
    10

    Question Battery Bank Charging

    So since we just got here a few months ago and needed power quickly we opted to spend the money for a really good inverter and we went the cheap route on the batteries with the plans to replace them within a year or 2 and got the golf cart batteries. We current have a 24v system using 4 golf cart batteries and will be adding 4 more this week. I have a question about charging them and can't seem to find the answer.
    I have a Xantrex DR inverter/charger 2000w,we're also planning on adding another inverter in a year or 2.
    With the golf cart batteries should I let them go all the way through the float charge? It says contact the battery manu. but I didn't get an answer from them they kept saying their batteries weren't meant for battery banks.
    Also how often should I or should I even equalize charge them? If I am suppose to equalize them do I have to turn off the propane stove and let the woodstove go out?
    Last edited by Alaskafamilyof3; 11-18-2008 at 11:08. Reason: left out info

  2. #2
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    If I understand you correctly you have 4 old 6 v battery = 24v and you want add 4 new 6v batteries in serial to increase your total amperage.



    If all of the 4 new battery are matched (voltage and internal resistance) and their total serial voltage and resistance = the total voltage and internal resistance of the old set of batteries, you can treat all batteries as a single 24 v battery. If they are not matches you need to charge the new and old battery separately for maximum performance.


    If it was me I would do one of four things, not use golf cart battery, use them knowing I will have problems, buy a match set, or buy the correct batteries.



    "With the golf cart batteries should I let them go all the way through the float charge?"

    I donít understand the question. Why would not want to put a float charge on a golf battery?

  3. #3
    New member
    Join Date
    Sep 2008
    Posts
    10

    Default

    The golf cart batteries we're the best we could do just moving up we didn't have the 100+ for each battery so we did what we could at that time.
    I can buy 4 more of the exact size and brand that I have already.That isn't a problem.

    I wasn't sure about the float charge,since I have never had a battery bank before I didn't know where or who to ask. The owners manuel for the inverter says contact the battery manu. which I did but they wouldn't tell me about the float charge. The only other person I know with a battery bank has lived here 10+yrs and has invested in the AGM batteries which we will do at tax time but we had to have something to hold us over until then.

    What about the equalization? Should I do that? It once again says contact the battery manu.

    I tried called a place in Fairbanks but all they wanted to do is act like I was a dumb woman for asking such questions and to tell me what a great deal he could get me if I bought several of the $100+ AGM batteries they had. Which I might do but not at this moment.

  4. #4
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    This is what I found on equalization? http://www.thesolarbiz.com/Battery_charging_article.htm

    Should you equalize your battery? I donít know if it a good idea, the reason is unless you know what youíre doing you could cause more problems.

    Golf cart batteries are not design for what youíre using them for and I can understand the manufacture. They will be blame for any problem you have when they go bad even throw it not there fault.

    What brand of golf cart batteries do you have?

  5. #5
    New member
    Join Date
    Sep 2008
    Posts
    10

    Default

    More problems? We don't have any problems at all with our system. Been using it just fine. I was hoping to find someone that had good knowledge of these systems to ask questions.
    Golf cart batteries can be used,I have been told that by several different places that sale inverters. Granted they will not give you the life span that the AGM batteries will. They will work better than deepcycle marine type.
    And it isn't unheard of to use them according to several places that sale off the grid type products. Not that it matters but I got the batteries at Sams.
    I guess the search goes on about the equalization. The inverter system manuel says do it every couple of months. No where in the book does it say what type of batteries you need for the system except that you need 24v to make it run.

  6. #6
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    The reason I wanted to know who made the batteries is so I could try and find out what the float voltage was and other information.

  7. #7
    New member
    Join Date
    Sep 2008
    Posts
    10

    Default

    The batteries are Energizer brand. After reading that link it says not equalize more than every 6 months or longer,not like the book that said every couple of months.

  8. #8
    Member Michael's Avatar
    Join Date
    Oct 2007
    Location
    Anchorage / Glennallen
    Posts
    162

    Default

    Nigel Caulder has a book titled Boatowners Mechanical and Electrical Manual. Very informative on how to maintain your electrical system. I could give you more info, but it's on my boat.

    We've been using Rolls Royce 6v batteries with a solar charger at our cabin for about 5 years with no problems. We did put hydro caps on them to contain the vapors. This is a cabin and not a house. Lights and a TV for the kidlet.

    Good luck.

  9. #9
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Alaskafamilyof3,

    Exactly which inverter do you have? a 2424? You need to look in the DR manual and select the correct charge setting for your batteries. If you have removable caps select the flooded battery setting. Next, select the total amperage of your battery bank. Since you're using 4 6v batteries your amperage is equal to one of your batteries. When you add 4 more batteries you'll connect them in series parallel and your amperage will double. Just select the correct amperage for now. Your DR will charge your batteries correctly according to what they need. You can see the charge evolve from bulk to float by watching the LED on your inverter. It'll turn from blinking orange to orange to green. You can run your generator 24/7 and your batteries will be fine. If you're using the inverter a lot I'd equalize once every couple of months. Turn your charge selector to one of the two equalization settings and run the generator. I use the manual timed setting. It'll take about 6-8 hours if your system is like mine. I normally use condensing caps on my batteries and will remove them and use the stock caps to equalize. If your place is small you may smell the batteries as they boil. Crack a window accordingly. You aren't creating a big health or explosion risk. Read the Xantrex manual for DR inverters. If you don't have one you can read it on-line. Your questions are good ones. And there's nothing wrong with the golf cart batteries. They don't have as much storage as some and they won't perform quite as well as some but you'll get several good years from them and they'll work great. Watch how long you can run your house with 4 batteries and make your decision about adding more based on that. If you add 2 more you'll gain 50% more time. 4 more will double your time. You may find that 4 is enough.

    Here's the new manual link. My DR inverter has the older style controls on the front and my comments are based on that.
    http://www.xantrex.com/web/id/271/p/...25/product.asp

  10. #10
    Member bushrat's Avatar
    Join Date
    Dec 2005
    Location
    Now residing in Fairbanks from the bush
    Posts
    4,363

    Default Another suggestion

    Alaskafamilyof3,

    Yes, like Pid said, good questions. And good answers from him!

    I just wanted to add another suggestion. Been on battery power here for 20+ years. I would not connect the new set of batteries in parallel with the old. Rather I would work out a switch system whereby you can use one bank at a time, and charge one bank at a time. Will be more of a hassle, but my experience has been that you will get much less life on a new set of batteries if you hook them up with the old set.

    If you keep track of how many amp-hours you use in a day, and know how many amps your charger is putting back into the system, that is also a good way to figure out when you need to charge and for how long, and when equalization is needed. Only problem with equalizing more often is the loss of water from the batteries, so keep an eye on that and refill accordingly with distilled water.

    Not familiar with that inverter/charger. What I use has a voltage set point pot so it can be set to whatever voltage I want on the high end. Sounds like Pid has that all figured out for your inverter.
    Good luck, and when you can afford it, spend the extra money on more high quality batteries; you'll be glad you did in the long run.

  11. #11
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    Mr. Pid, Good post, I was couriest enough I read the manual yesterday. You mention when adding batteries you increase total amperage. Your information is correct as long as the charging system can charge the battery to full power. With out knowing more information; I mean a lot more information adding batteries could lower the total usable amperage. I think having a battery switch that switches between battery bank A and B would be the best way to go.


    Once again very good post.

  12. #12
    Member bushrat's Avatar
    Join Date
    Dec 2005
    Location
    Now residing in Fairbanks from the bush
    Posts
    4,363

    Default Battery basics

    Quote Originally Posted by Rutting Moose
    With out knowing more information; I mean a lot more information adding batteries could lower the total usable amperage.
    There is no situation I can envision where you would have lower amp-hour capacity by adding more batteries as suggested in this thread.

    For example, if you are running a 24volt system and using four six-volt batteries in series, the amp-hour capacity is equal to whatever the amp-hour capacity is for one of those six-volt cells. Say one of those six volt batteries is rated at 150 amp hours. Even though you connect them all in series, you only still have 150 amp-hours at 24 volts.

    If you add another set - another four in series - and then wire that set in parallel to the other, you will DOUBLE your amp hour capacity.

  13. #13
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Another consideration with battery/inverter systems is input current. The DR 2412 inverter that I use has a built-in 120 amp charger. The ability to utilize the charger is dependent on the generator. Mine won't function fully with less that a 5.5K generator.

  14. #14
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    1. You are correct when you first put batteries in parallel and stayed true if;

    If all of the 4 new battery are matched (voltage and internal resistance) and their total serial voltage and internal resistance = the total voltage and internal resistance of the old set of batteries, you can treat all batteries as a single 24 v battery. If they are not match you need to charge the new and old battery separately for maximum performance.

    2. If you do not do the above, the battery bank with the higher voltage will control the charging, over time the battery bank with the lower voltage will deterated; and there for 2 batteries in parallel will not have 2x the amperage as one battery.

    3. and if your statement was true, there would be no reason to use a battery isolator.

    4. and that is also why you use a switch to select between the new and old battery bank.


    Quote Originally Posted by bushrat View Post
    Alaskafamilyof3,

    Rather I would work out a switch system whereby you can use one bank at a time, and charge one bank at a time. Will be more of a hassle, but my experience has been that you will get much less life on a new set of batteries if you hook them up with the old set.


    5. and yes, it is just battery basics. 

  15. #15
    Member
    Join Date
    Oct 2007
    Location
    Kenai pen, in summer. Matsu vally in winter
    Posts
    243

    Default

    I have just read this thred and it sounds like you guys know all about it. I have some ??s. At my cabin i have just two 6 volt batterys they are i think the L-16s they are about 1 year old. I do have 4 more new ones to bring out. The two do work better than i thought they would. I just use them for the tv and a couple of lights I have just a small 750 converter and a 15 amp charger. I have 2 2000 wt honda gen with the cord to hook them together.
    I am going to up grade. The set up i have now will go in the shed and i will bring the new batterys to the cabin.
    My ??s are 12 volt verses 24 volt do you get better perfomance with the 24 volt. dose the 24 volt last longer on a charge do they charge better or faster? Can someone explane equalization. How to, and why.
    I was thinking of getting two more batterys then i would have 6 new ones If i went with the 24 volt system would 6 work or would i haft to have 8.
    The cabin is going to need more electric as i get it done. I am going to put in the water system It will just be a holding tank and a 12 or 24 volt pump I think a 1500 wt converter will work.
    Any suggestions on a converter with a charger that a 4000 wt gen would be able to handle.
    I do have a 10k northern lights but im not shure if i want to use it. Overkill
    I would like to have the 6k. for the fuel burn.
    Dose anyone know how much the L-16 batterys are going for now I hear lead went up 30 percent in the last year. I payed 250 per for them Just over a year ago.. Any input or advice would be great I use the cabin more in the wintertime than in summer for now anyway.

  16. #16
    Member bushrat's Avatar
    Join Date
    Dec 2005
    Location
    Now residing in Fairbanks from the bush
    Posts
    4,363

    Default

    Lance, there is lots of info on the internet relating to your questions. Inre 12volt vs 24volt systems, the performance benefits you asked about relate to line losses, expense of wire runs and safety for the most part. Thing to keep in mind is that any appliance (of equal wattage) will draw half the amps on 24 volts than it does for 12. This has serious ramifications regarding wire gauge used and loss and heating in wire. Many well pumps that are a ways down the well can't be run with 12volt pumps...amperage on the line is so high it isn't practical. (ie you can't run welding cable that far <grin>. Well you could, but it would be very spendy and take up a lot of room.) Many who have their battery/inverter system in outbuildings use 24 volts, or if you had, say, a solar array a distance from the batteries 24 volts (or higher) may be the way to go.

    An easy formula to use and remember has the acronym PIE:
    P (power in watts) = I (current in amps) x E (volts)

    Much can be figured out using that, like your question on generator wattage etc. I priced L-16s this fall when I bought another set of batteries from ABS in Fbks. They were well over $300 each.

    You'll need 8 L-16s for the 24volt system you spoke of. If you had six, you'd only have enough for one 24volt bank with two left over...so you could use those in series as a 12 volt bank but you'd need two more for another 24volt bank.

    Equalization is charging batteries at a much higher voltage than float voltage for a period of time. With a 12volt system that would be ~15 volts for a spell. What happens over time as you charge/discharge a lead-acid battery is that you will have some sulphation buildup on the plates. That decreases amp-hour capacity and efficiency. Equalizing will "knock" that sulphation off if you do it periodically. There are some other methods of preventing sulphation too...but can't go into those now.

    Only other suggestion based on your setup would be to make sure to fully charge batteries before leaving. I like to keep mine in a warm spot as well in the cabin and off the floor, really helps to lengthen capacity and keep voltage up. Some of my stuff doesn't run if I get too close to twelve volts (ham radio).
    Good luck,

  17. #17
    Member
    Join Date
    Oct 2007
    Location
    Kenai pen, in summer. Matsu vally in winter
    Posts
    243

    Default

    Thanks for the info. It will be awhile befor i do the uppgrade by then i will have this all figured out. I was wondering if anyone knows the best way to store new batterys I have them in a warm safe place I didnt want to charge them thinking they wouldnt be new anymore lol.

  18. #18
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,246

    Default

    The manufactory is the best person to ask, because they are the experts on their battery. If they can not help, store in a cold area and every 6 months put a charge them.

  19. #19

    Default

    It never ceases to amaze me the knowledge on this board.

  20. #20

    Default Matsuthunder

    You should have an inverter to change power from 12 volt DC to 115 volts AC; a converter changes 115 volts AC to 12 volts DC using a transformer. To charge your batteries don't use the charging feature on the Honda generator. The Honda is only capable of charging batteries at 8 amps and is not effeceint as a cabin charger. Charging requires a seperate higher amperage charger to be effecient and timely.
    As for a 24 versus 12 volt power system. The major difference in the systems is that if you use a 24 volt system the wireing to connect the batteries together, the wires to connect to the charger, the wires to the inverter, and the wires to your soon to be purchased solar panels can be much smaller. The cost of copper wire being what it is this will be a large savings in the initial system versus the cost of 2 more batteries. The batteries will also discharge at half the rate at 24 volt allowing longer run times between charging.
    " Americans will never need the 2nd Amendment, until the government tries to take it away."

    On the road of life..... Pot holes keep things interesting !

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •