Problem With Inverter - Panel/Battery Setup

TrioxinTrioxin Registered Users Posts: 1
I'm just starting out with solar, trying to get something working before I scale up. Currently, I have 2 100w panels (Just 1 hooked up at the moment). I have a 1500w continuous inverter (12v) and a car battery hooked to it. I also have a controller. The battery is fully charged and has a charger hooked up to it as well as the panel. The readout on the inverter is showing 12.6v (I was expecting it to show more while battery is being charged). As soon as I turn on my mini-heater that's plugged into the inverter, I get OCP error. The manual says that's an overheating error but it doesn't seem to be hot and I don't think the fans were going. It happens as soon as I plug in a device. I've tried two different heaters. The one that draws the most power draws 400w max. It's a new inverter. What I'm using...

cobra cpi 1575 (Manual:
thunderbolt solar magnum 12v charge controller
12v battery (As a car battery)



  • dennis461dennis461 Registered Users Posts: 108 ✭✭✭
    Check the DC input voltage at the inverter under your fault conditions.  If it is lower than the rated input voltage (10.4vdc in manual) then perhaps the  alarm board is not functioning properly.

    Try using a small 50 watt load rather than a heater, to verify the inverter is not defective from the factory.
    Camden County, NJ, USA
    19 SW285 panels
    SE5000 inverter
    grid tied
  • BB.BB. Super Moderators, Administrators Posts: 28,320 admin
    edited January 2017 #3
    A car battery may support a few hundred Watt load reliably.

    If you are using jumper cable/alligator clips, they will not work.

    The connection to the inverter needs heavy cable and bolted connections.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 3,128 ✭✭✭✭✭
    +1 on what Bill and Dennis said. Also, you're right that a fully charged battery on a charger should be higher than 12.6v. It should be around 12.8v resting at full charge. More like 14ish connected to charger (assuming charger has power).
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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