Results 1 to 20 of 20
  1. #1
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943

    12v deep cycle batteries: charging via alternator?

    Right, I've been searching high and low to figure this out, and now I'm at good ol OCF.

    Basically, I need to find a way to charge a large (100-200ah) battery via a car alternator. Now I know it can't just be lopped on to the preexisting 12v circuit in the car and all, but I think I'm going to need some sort of voltage regulator going to the deep cycle. Problem is, I have no clue what to get. All I can find is expensive chargers that work from 120v, not 12v. The only alternative seems to be buying a AGM battery for about twice the price just so it doesn't need anything fancy to be charged.

    The only other options for charging would be solar panels ($$$) or a generator ($$$$), so... what should I do?
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  2. #2
    Senior Member


    Bobnova's Avatar
    Join Date
    May 2009
    Location
    Humboldt
    Posts
    20,950
    It can totally just be connected to a car. The alternator will charge it more slowly and be under a bit more stress than if there was only one battery connected, but it'll work fine.

    Failing that, you can run an alternator off a lawn mower motor, I built a charger like that.
    "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe." -- Einstein (maybe)

    Thinking about an Asus motherboard? Think again.

    How to check your PSU with a multimeter.

    17bXw5t51rEBXGavJFMJsC8g7HQgThUGc7

  3. #3
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Ah, well that makes things a lot easier. I'll probably keep a voltmeter on it to keep track of what voltage is going to it, but it's good to know I won't need to spend a few hundred on voltage regulators.

    Time to go spend money!

    EDIT: The thanks button is gone, so just pretend I clicked it.
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  4. #4
    Member Mpegger's Avatar
    Join Date
    Nov 2001
    Location
    NYC
    Posts
    2,999
    Any reason why you cannot just get a cheap charger from a local car parts store? Many alternators don't start charging till after a certain RPM, so I would imagine you would be spending more on gas, then just getting a charger and leaving it charging over night.
    NZXT Switch 810 / ASRock Z97 Extreme4 / i7 4790K @ 4.6 / 32GiB / 780Ti
    ESXi server / i7-3770s / 16GiB / 16TB ZFS-z2
    Dell R710 in the works...

    -----------------------------
    [GB ≠ GiB] [MB ≠ MiB] [kB ≠ kiB]
    "Apparently, Plaintiff believes that he could sue an egg company for fraud for labeling a carton of 12 eggs a “dozen,” because some bakers would view a “dozen” as including 13 items." - Western Digital 2006

    "One World, One Web, One Program" - Microsoft
    "Ein Volk, Ein Reich, Ein Führer" - Hitler

    (Microsucks) Avatar and quote on loan from AntmanMike
    Heatware

  5. #5
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Quote Originally Posted by Mpegger View Post
    Any reason why you cannot just get a cheap charger from a local car parts store? Many alternators don't start charging till after a certain RPM, so I would imagine you would be spending more on gas, then just getting a charger and leaving it charging over night.
    I won't have a wall to plug into most of the time, although I'm already getting a charger for the occasions when I actually do.
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  6. #6
    Member with Some Fancy Text Under His Name CompuTamer's Avatar
    Join Date
    Jan 2009
    Location
    Brandon Mississippi
    Posts
    2,705
    Just make sure that your alternator has the headroom to charge a second battery while powering everything for the car. They're not really meant to charge batteries from anything below about 10% if i remember correctly. (Granted, this was for a alternator for a Hyundai Excel, not a powerful car)
    Intel Core i7 C0 @ 4.01GHz with 1.388 vCore ..........................................Intel i7 4500U
    Intel DX58SO Motherboard IOH + QPI @ 1.250 Volts..............................Lenovo Yoga 2 Pro
    Sony Optiarc Blu-Ray Drive.................................................. ...............802.11AC
    8 GB G-Skill Sniper DDR3 1600 @ 1.65 Volts ...........................................8GB DDR3 1600Mhz RAM
    60GB OCZ Solid 3 + 320GB WD Blue+ 1TB WD Green...............................Samsung 250GB SSD
    Antec 900.................................................. .......................................All Metal Body
    BFG GS-650.................................................. .....................................Lenovo Power Brick + 54Whr Battery
    XFX Radeon HD 4850 (660/1060 53C Idle 62C Load) @ 1.31 vCore............Intel HD4400
    Dual Dell E2311H LED 1920x1080.................................................. .......13.6" 3200x1800 Touchscreen
    Windows 7 Ultimate.................................................. ..........................Windows 8.1
    Those specs up there? They're silent. Silence is good. Very good.
    Your Core 2 Quad is based off of the Pentium pro in a few ways.

  7. #7
    Member nd4spdbh2's Avatar
    Join Date
    Nov 2005
    Location
    Camarillo, CA!
    Posts
    9,213
    question... why are you putting a deep cycle batt in a car?
    #12 in the 4ghz core 2 duo club baby! - 52 inches of CRYSIS! - Black Belt Ubercloxx0r -- Heatware
    Main -- Lian Li V2000b -- i7 2700k -- MSI Z68A-GD80 -- 12gb 1600 -- GTX560Ti --Adata 128gb S510 & 2x500gb -- Seasonic S12 600w -- Dell 2209WA
    HTPC -- Silverstone GD05B -- E7200 @ 3.2ghz -- G41-M7 -- 4GB 800mhz -- g210 passive -- 320gb 2.5in WD -- Antec EA 430w -- 52inch Samsung LCD
    Server -- Antec NSK4480B -- E3300 @ 2.5ghz -- ECS G33T-M2 -- 3gb 667mhz -- Onboard Vid -- 500Gb + 1TB hatachi + 1tb WD -- Zalman 400w
    Netbook - Dell Mini 9 - Atom 1.6ghz - 8GB ssd - 2GB pc6400 - WIN 7 PRO!
    Need 4 Speed - BH

  8. #8
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Quote Originally Posted by CompuTamer View Post
    Just make sure that your alternator has the headroom to charge a second battery while powering everything for the car. They're not really meant to charge batteries from anything below about 10% if i remember correctly. (Granted, this was for a alternator for a Hyundai Excel, not a powerful car)
    I think my van is supposed to have a 78 amp, I have to go take a look. Probably get that done today.

    Quote Originally Posted by nd4spdbh2 View Post
    question... why are you putting a deep cycle batt in a car?
    Hard to live without electricity, no?
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  9. #9
    Member
    Join Date
    Sep 2007
    Posts
    277
    What is this for, a small boat with an outboard motor?

    Do realize that you will need to run your car's engine for hours on end in order to charge that battery. It just does not make much sense.

  10. #10
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Quote Originally Posted by Trottel View Post
    What is this for, a small boat with an outboard motor?

    Do realize that you will need to run your car's engine for hours on end in order to charge that battery. It just does not make much sense.
    A van.

    I'll be driving on the highway a good bit so using the alternator to charge won't hurt at all.
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  11. #11
    "The Expert" Archer0915's Avatar
    Join Date
    Nov 2008
    Location
    East Carolina University Grad School
    Posts
    4,792
    Quote Originally Posted by KonaKona View Post
    A van.

    I'll be driving on the highway a good bit so using the alternator to charge won't hurt at all.
    A van? Are you having trouble with the DC to AC kicking off?
    People that buy OEM systems think Linux was a Charlie Brown character, a registry is something you see at target to buy shower gifts, RAM is a Dodge truck and a hard drive is DC at rush hour.
    Current Active Fleet:
    Daily Driver i7 3740QM T530
    Work Rig/networked backup - i7 4770K@4.4, 24GB Ram, 7850 GFX Bedroom PC - i7 870 @ 3.4, 16GB Ram, 6670 GFX
    Home School PC (kids) SB Celery @1.6, 4GB Ram, On Chip GFX Living Room HTPC - E-450@1.9 GHz, 4GB Ram
    Game Rig (kids)- 3570K@4.7, 12GB Ram, 465GTX + 9800GT (PhysX) using intel SRT
    Test Bed - In flux

  12. #12
    Member nd4spdbh2's Avatar
    Join Date
    Nov 2005
    Location
    Camarillo, CA!
    Posts
    9,213
    if its a camper type van i could see the use in a second 12v deep cycle batt that you use when your parked camping for a coupla days. thers no harm in using the alternator to charge it , but like stated make sure you have either 1. a beefy nuf alternator to charge both batts at a time. 2. get a beffier one, or 3, get a second one.
    #12 in the 4ghz core 2 duo club baby! - 52 inches of CRYSIS! - Black Belt Ubercloxx0r -- Heatware
    Main -- Lian Li V2000b -- i7 2700k -- MSI Z68A-GD80 -- 12gb 1600 -- GTX560Ti --Adata 128gb S510 & 2x500gb -- Seasonic S12 600w -- Dell 2209WA
    HTPC -- Silverstone GD05B -- E7200 @ 3.2ghz -- G41-M7 -- 4GB 800mhz -- g210 passive -- 320gb 2.5in WD -- Antec EA 430w -- 52inch Samsung LCD
    Server -- Antec NSK4480B -- E3300 @ 2.5ghz -- ECS G33T-M2 -- 3gb 667mhz -- Onboard Vid -- 500Gb + 1TB hatachi + 1tb WD -- Zalman 400w
    Netbook - Dell Mini 9 - Atom 1.6ghz - 8GB ssd - 2GB pc6400 - WIN 7 PRO!
    Need 4 Speed - BH

  13. #13
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Quote Originally Posted by Archer0915 View Post
    A van? Are you having trouble with the DC to AC kicking off?


    Quote Originally Posted by nd4spdbh2 View Post
    if its a camper type van i could see the use in a second 12v deep cycle batt that you use when your parked camping for a coupla days. thers no harm in using the alternator to charge it , but like stated make sure you have either 1. a beefy nuf alternator to charge both batts at a time. 2. get a beffier one, or 3, get a second one.
    With any luck I'll find out what's in it this weekend or monday. I'm pretty sure it's a 78 amp though.
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  14. #14
    "The Expert" Archer0915's Avatar
    Join Date
    Nov 2008
    Location
    East Carolina University Grad School
    Posts
    4,792
    Quote Originally Posted by KonaKona View Post
    My inverter kicks off when the sound on the mobile theater is kicked up while watching a DVD, both ACs are kicking and I hit the brakes. I have been thinking of adding a batterey above the cab.

    People that buy OEM systems think Linux was a Charlie Brown character, a registry is something you see at target to buy shower gifts, RAM is a Dodge truck and a hard drive is DC at rush hour.
    Current Active Fleet:
    Daily Driver i7 3740QM T530
    Work Rig/networked backup - i7 4770K@4.4, 24GB Ram, 7850 GFX Bedroom PC - i7 870 @ 3.4, 16GB Ram, 6670 GFX
    Home School PC (kids) SB Celery @1.6, 4GB Ram, On Chip GFX Living Room HTPC - E-450@1.9 GHz, 4GB Ram
    Game Rig (kids)- 3570K@4.7, 12GB Ram, 465GTX + 9800GT (PhysX) using intel SRT
    Test Bed - In flux

  15. #15
    Trashcan Man Member
    KonaKona's Avatar
    Join Date
    Nov 2008
    Location
    College radio?
    Posts
    2,943
    Oh, I haven't tested it yet but I don't think it'll draw more than the inverter can handle. I don't see why the inverter is kicking off because of the power input though, have you ran a voltmeter to the inverter connection to see if it's actually dropping the volts too much? It might just be the inverter itself, we had one that would cut out way before it's rated voltage.
    LTC: LbVSSv4Phj1NWvxBw76zmhV8K1P63xhYJ9

    Member of the MOAR VOLTS™ club.

  16. #16
    Member with Some Fancy Text Under His Name CompuTamer's Avatar
    Join Date
    Jan 2009
    Location
    Brandon Mississippi
    Posts
    2,705
    Quote Originally Posted by Archer0915 View Post
    My inverter kicks off when the sound on the mobile theater is kicked up while watching a DVD, both ACs are kicking and I hit the brakes. I have been thinking of adding a batterey above the cab.

    Ha, break lights = straw that broke the camel's back?

    Our car has issues with running the AC, the Bright lights, the breaklights, and the radio at the same time. It has a 120amp alternator on a 136HP engine Turning the bright lights on actually bogs the engine down. As does turning the blower up to max.




    PS: Can i have your van? Pretty please? That thing looks awesome
    Intel Core i7 C0 @ 4.01GHz with 1.388 vCore ..........................................Intel i7 4500U
    Intel DX58SO Motherboard IOH + QPI @ 1.250 Volts..............................Lenovo Yoga 2 Pro
    Sony Optiarc Blu-Ray Drive.................................................. ...............802.11AC
    8 GB G-Skill Sniper DDR3 1600 @ 1.65 Volts ...........................................8GB DDR3 1600Mhz RAM
    60GB OCZ Solid 3 + 320GB WD Blue+ 1TB WD Green...............................Samsung 250GB SSD
    Antec 900.................................................. .......................................All Metal Body
    BFG GS-650.................................................. .....................................Lenovo Power Brick + 54Whr Battery
    XFX Radeon HD 4850 (660/1060 53C Idle 62C Load) @ 1.31 vCore............Intel HD4400
    Dual Dell E2311H LED 1920x1080.................................................. .......13.6" 3200x1800 Touchscreen
    Windows 7 Ultimate.................................................. ..........................Windows 8.1
    Those specs up there? They're silent. Silence is good. Very good.
    Your Core 2 Quad is based off of the Pentium pro in a few ways.

  17. #17
    "The Expert" Archer0915's Avatar
    Join Date
    Nov 2008
    Location
    East Carolina University Grad School
    Posts
    4,792
    The inverter has a built in sensor that tells it that the batterey is not providing enough i. The sensor is way off though because my batterey powered a lot more than that using other inverters. Easiest thing I guess would be swap out the inverter but it would be useless if I removed it (I mounted and epoxyed it) because it would be destroyed in the process.
    People that buy OEM systems think Linux was a Charlie Brown character, a registry is something you see at target to buy shower gifts, RAM is a Dodge truck and a hard drive is DC at rush hour.
    Current Active Fleet:
    Daily Driver i7 3740QM T530
    Work Rig/networked backup - i7 4770K@4.4, 24GB Ram, 7850 GFX Bedroom PC - i7 870 @ 3.4, 16GB Ram, 6670 GFX
    Home School PC (kids) SB Celery @1.6, 4GB Ram, On Chip GFX Living Room HTPC - E-450@1.9 GHz, 4GB Ram
    Game Rig (kids)- 3570K@4.7, 12GB Ram, 465GTX + 9800GT (PhysX) using intel SRT
    Test Bed - In flux

  18. #18
    Member Wathnix's Avatar
    Join Date
    Feb 2004
    Location
    New Hamster
    Posts
    947
    I would recommend that you run your wiring from the Van's battery terminals to your deep cycle battery and have a 100 amp fuse between the two batteries, connected on the positive wire and physically locate the fuse as near to the van's battery terminals as you can. You should be able to buy the fuse and fuse holder cheap at an auto parts supplier.

    A deep cycle batter is the same as a regular car battery but it is made to lose more of it's charge without damaging the battery AS MUCH as a regular lead acid. If you totally discharge a brand new car battery and leave around for a few weeks it will be totally dead.

    I would also recommend you only start charging the deep cycle after you have been running the van for at least 10 minutes, give the alternator time to charge the van's battery before you throw more stress on it. Also keep in mind that you are putting alot more stress on your charging system. You can expect to replace your van's battery and alternator sooner or more often than usual.


    You may want to simply consider buying a small portable generator. I think some of them can also charge deep cycle batteries.
    "Beer is how we know God loves us and wants us to be happy" - Benjamin Franklin.
    Thermaltake Tsunami case, Q6600 CPU, XFX mobo, 500GB HDD, GTX 460 video card, Corsair 520HX PSU

  19. #19
    "The Expert" Archer0915's Avatar
    Join Date
    Nov 2008
    Location
    East Carolina University Grad School
    Posts
    4,792
    Quote Originally Posted by CompuTamer View Post
    PS: Can i have your van? Pretty please? That thing looks awesome
    Dude this thing rides better than a Caddy and still had acceleration at 100+ I could never part with it. If my wife and I are having a fight there is nutin better for fishing.
    People that buy OEM systems think Linux was a Charlie Brown character, a registry is something you see at target to buy shower gifts, RAM is a Dodge truck and a hard drive is DC at rush hour.
    Current Active Fleet:
    Daily Driver i7 3740QM T530
    Work Rig/networked backup - i7 4770K@4.4, 24GB Ram, 7850 GFX Bedroom PC - i7 870 @ 3.4, 16GB Ram, 6670 GFX
    Home School PC (kids) SB Celery @1.6, 4GB Ram, On Chip GFX Living Room HTPC - E-450@1.9 GHz, 4GB Ram
    Game Rig (kids)- 3570K@4.7, 12GB Ram, 465GTX + 9800GT (PhysX) using intel SRT
    Test Bed - In flux

  20. #20
    Member JCLW's Avatar
    Join Date
    Apr 2002
    Location
    Back in Toronto
    Posts
    3,758
    A flooded deep cycle battery has fewer, thicker plates that resist warping when deeply discharged.

    A flooded starting battery has lots of thin plates (more surface area) for higher cranking amps.

    Most car alternators are not rated continuous duty. However your van one might be.

    If you have a continuous duty alternator you want an automatic charging relay such as: http://bluesea.com/category/2/productline/overview/387

    If you have an intermittent duty alternator, or if you want to separately regulate the charging of your deep cycle bank you want a DC-DC charger such as:
    http://www.xantrex.com/power-product...y-charger.aspx
    ♫♪ ☺ ♫♪

Posting Permissions

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