Battery charger and regulator failure

System
System Posts: 2,511 admin
in General Solar Power Topics #1
New here, please be gentle with your replies :-)

Our hunting camp has a small 12v system in place so that we don't have to run the generator all the time. My question is: can a battery charger connected to the batteries to charge them when the generator is running, damage the solar charge regulator? Mine failed after less than a year and maybe 20 days of generator usage. I'm on a very slim budget for the cabin and don't want to toss a new regulator on only to have it fail again.

The system looks like this:
Harbor Freight 45w solar system: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599
Two Walmart 105ah deep-cycle batteries (yes, I know this isn't the optimum battery - again $ was the issue)
Schumacher 12A automatic battery charger with deep-cycle mode.
AIMS 300w pure sine inverter: http://www.invertersrus.com/inv300ps.html

We run a car stereo and a couple lights off the 12v and added the inverter mainly (but not the only reason) to be able to run the ceiling fans on winter mornings to circulate heat without having to go out and start the generator. Everything was working well until I noticed the charge indicator wasn't on on the regulator. A quick check with a voltmeter showed it was no longer passing voltage from the panels. Is this just a coincidental failure, or can the charger damage the regulator when the generator is running?

Thanks for your help!
aj
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Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: Battery charger and regulator failure

    it is possible, but even i can't be 100% sure. i am unfamiliar with the regulation in their controller. if it shunts to ground excess power then yes power from the battery charger along with the power from the pvs could've overloaded it. controllers like those by morningstar in the sunsaver series and many others open up the circuit rather than shorting to ground and are far less likely to blow out. without knowing the full circumstances it's hard for me to say that nothing else had caused this to happen. an ac ground loop could pass high voltage ac currents into it as well. be very sure the battery charger hasn't any problems as i had one of that make internally short sending ac power to my sunsaver 10 that immediately blew out due to full 110vac being imposed upon it. i do recommend getting a higher quality charger as that type is not good for your batteries on a regular basis anyway due to no regulation or protections. feeding the cheap charger as i did into a controller like the sunsaver works, but as i said it has its risks too. the iota chargers are good, but cost more and do watch the water levels on those batteries with the cheapo chargers as they could boil out all of their electrolyte.
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  • kc8adu
    kc8adu Solar Expert Posts: 50 ✭✭✭
    #3
    Re: Battery charger and regulator failure

    remember that much of what harbor freight sells is CHEAP and often LOW QUALITY.
    get a entry level charge controller from a name brand and enjoy your system.
    a good one wont care if you charge from another source.it will just shut off when its setpoint is reached.
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  • System2
    System2 Posts: 6,290 admin
    #4
    Re: Battery charger and regulator failure

    Thanks for the replies. I plan to get a small PWM regulator to replace the (obviously) cheap one that came with the system. The battery charger is a new-style fully-automatic with a deep cycle mode so I think it's fine for the task. As I mentioned, we only use the cabin 20-25 days a year so the batteries are mostly just sitting there happily topped off by the array.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Battery charger and regulator failure

    If the charger does not have a remote battery temperature probe... Probably try to install the charger next to the battery bank. Batteries that are charged according to their actual temperature should last much longer (especially if the batteries/controller are not in a temperature controlled environment like a home).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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