Inexpensive charge controller that works with AGM batteries

bratan
bratan Solar Expert Posts: 32 ✭
in Solar Beginners Corner #1
I got a cheap 30 A controller for my 100W panel and 125Ah Vmaxtanks AGM battery of eBay. It doesn't mention anywhere in the manual if it supports sealed batteries (i.e. AGM) and in floating mode it seems to output too much voltage (14.2V). In fact manual says something about "gassifying electrolyte in floating mode". No way to disable floating mode or change it's voltage, so I'm looking for another charge controller.
Can someone recommend me a PWM CC under $100 that will 100% support AGM? I'd really like to have LCD screen on it as well :)
· Share on Twitter

Comments

  • IYAPYSNF
    IYAPYSNF Registered Users Posts: 8 ✭
    #2
    Re: Inexpensive charge controller that works with AGM batteries

    Most PWM controllers that I have come across will work fine with AGM batteries. AGM's are still flooded correct?
    · Share on Twitter
  • bratan
    bratan Solar Expert Posts: 32 ✭
    #3
    Re: Inexpensive charge controller that works with AGM batteries
    IYAPYSNF wrote: »
    Most PWM controllers that I have come across will work fine with AGM batteries. AGM's are still flooded correct?
    I'm not 100% sure, but I think they are not flooded. They have Absorbed Glass Matt that soaked with acid. These are sealed batteries, meaning they do not vent hydrogen under normal conditions. But if they are overcharged they will vent it via safety valve, damaging battery as you can't add water to them...
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,660 admin
    #4
    Re: Inexpensive charge controller that works with AGM batteries

    Look at MorningStar's line:

    http://www.solar-electric.com/inverters-controllers-accessories/chco/mochco/stpwmchco.html

    Stecca is a good brand... PCM a bit more but lots of programmable options, includes meter/display:

    http://www.solar-electric.com/inverters-controllers-accessories/chco/stchcoforsoe/stpr10sochco.html

    There are lots of Chinese imports out there--Some with lots of settings. If you want to give one a try--A few people here can probably give you some units they have had good luck with.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #5
    Re: Inexpensive charge controller that works with AGM batteries
    bratan wrote: »
    I'm not 100% sure, but I think they are not flooded.

    AGM and Gel lead acid batteries are NOT flooded. --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
    · Share on Twitter
  • mtdoc
    mtdoc Solar Expert Posts: 600 ✭✭
    #6
    Re: Inexpensive charge controller that works with AGM batteries

    Yeah, I can recommend the Stecca that BIll linked. I have one on a small shed system and it's great. The LCD gives lots of useful info including battery voltage, charge/discharge amps and a decent SOC estimate. It's a bit over your budget but I don't think you'll find a quality CC with an LCD for less than $100. It does have a Gel/AGM setting.
    · Share on Twitter
  • Photowhit
    Photowhit Solar Expert Posts: 6,016 ✭✭✭✭✭
    #7
    Re: Inexpensive charge controller that works with AGM batteries
    bratan wrote: »
    I got a cheap 30 A controller for my 100W panel and 125Ah Vmaxtanks AGM battery of eBay. It doesn't mention anywhere in the manual if it supports sealed batteries (i.e. AGM) and in floating mode it seems to output too much voltage (14.2V). In fact manual says something about "gassifying electrolyte in floating mode". No way to disable floating mode or change it's voltage, so I'm looking for another charge controller.
    Can someone recommend me a PWM CC under $100 that will 100% support AGM? I'd really like to have LCD screen on it as well :)

    I'd suggest checking out the battery manufacturer's site, which states;

    2- Fully recharge your batteries. A float charge of 48-96 hours at room temperature is highly recommended (13.5-13.7V for 12V or 6.7-6.85V for 6V batteries). Or you can fast charge your batteries (14.5V for 12V or 7.2V for 6V batteries) for 12-24 hours.

    This would suggest your 14.3 is within specs, I haven't read it all, but it might suggest they are sold with out a charge...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
    · Share on Twitter
  • bratan
    bratan Solar Expert Posts: 32 ✭
    #8
    Re: Inexpensive charge controller that works with AGM batteries
    Photowhit wrote: »
    I'd suggest checking out the battery manufacturer's site, which states;

    2- Fully recharge your batteries. A float charge of 48-96 hours at room temperature is highly recommended (13.5-13.7V for 12V or 6.7-6.85V for 6V batteries). Or you can fast charge your batteries (14.5V for 12V or 7.2V for 6V batteries) for 12-24 hours.

    This would suggest your 14.3 is within specs, I haven't read it all, but it might suggest they are sold with out a charge...
    I might be wrong, but that sounds like float charge is not same as fast charge? To me it sounded like float charge = 13.5-13.7V, regular = 14.5V. So it seems float voltage was above recommended.
    Anyway, thank you all for your recommendations! I almost went for Stecca, and then I stumbled upon Morningstar ProStar PS-30M for $135 on ebay (without package) so I went ahead and ordered it! :) A little over budget, but still great deal.
    · Share on Twitter
  • Photowhit
    Photowhit Solar Expert Posts: 6,016 ✭✭✭✭✭
    #9
    Re: Inexpensive charge controller that works with AGM batteries

    If the batteries can withstand 14.5 for 12-24 hours with out venting... your good.

    Charging with solar you will have a finite time in which to charge. There is a typical progression in charging batteries, bulk until the voltage 'runs away' typically @80%, the charge controller limits the 'run away' at a voltage level called absorb, once batteries are fully charged the voltage is reduce to a level called float.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
    · Share on Twitter
  • bratan
    bratan Solar Expert Posts: 32 ✭
    #10
    Re: Inexpensive charge controller that works with AGM batteries
    Photowhit wrote: »
    If the batteries can withstand 14.5 for 12-24 hours with out venting... your good.

    Charging with solar you will have a finite time in which to charge. There is a typical progression in charging batteries, bulk until the voltage 'runs away' typically @80%, the charge controller limits the 'run away' at a voltage level called absorb, once batteries are fully charged the voltage is reduce to a level called float.

    Thank you! That makes sense! :)
    · Share on Twitter
  • Plowman
    Plowman Solar Expert Posts: 203 ✭✭✭✭✭
    #11
    Re: Inexpensive charge controller that works with AGM batteries

    No experience with Morningstar's ProStar controllers, but my Tristar 45 charging voltage is easily programmable with DIP switches. Fairly wide range.

    Mine doesn't have a LCD screen, just blinking LEDs. The meter is extra, not worth the money, IMHO, since it doesn't measure the battery input/output via a shunt like the Trimetric and similar meters.
    · Share on Twitter
  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
    #12
    Re: Inexpensive charge controller that works with AGM batteries
    bratan wrote: »
    I might be wrong, but that sounds like float charge is not same as fast charge? To me it sounded like float charge = 13.5-13.7V, regular = 14.5V. So it seems float voltage was above recommended.
    Anyway, thank you all for your recommendations! I almost went for Stecca, and then I stumbled upon Morningstar ProStar PS-30M for $135 on ebay (without package) so I went ahead and ordered it! :) A little over budget, but still great deal.

    This should make you feel better. The first controller I purchased here (Cambodia) locally, was a MorningStar ProStar 30m. I paid $250 USD for it!
    Paul
    · Share on Twitter
  • Alaska Man
    Alaska Man Solar Expert Posts: 252 ✭✭
    #13
    Re: Inexpensive charge controller that works with AGM batteries

    I've had mine up to 14.8 and regularly to 14.6. I've read that AGM's are happier with a higher float voltage. I sure wouldn't sweat 14.2
    · Share on Twitter
  • bratan
    bratan Solar Expert Posts: 32 ✭
    #14
    Re: Inexpensive charge controller that works with AGM batteries
    Alaska Man wrote: »
    I've had mine up to 14.8 and regularly to 14.6. I've read that AGM's are happier with a higher float voltage. I sure wouldn't sweat 14.2
    Thanks for the info! I guess they can tolerate this, I just didn't want to take any chances with $280 battery :)
    ILFE wrote: »
    This should make you feel better. The first controller I purchased here (Cambodia) locally, was a MorningStar ProStar 30m. I paid $250 USD for it!
    Yikes! Yeah I guess I got a great deal, just hope it works :)
    · Share on Twitter

Categories