problem with controller/regulator

leaf · March 2012

I have a small solar system set up in an RV: 12V, two 6V batteries, a 120W panel, and a 10amp controller.

At the moment I am only running a laptop, car stereo and phone charger, as well as a water pump. The water pump is connected straight off the battery, the other wiring goes through the controller. I also have a monitor inside telling me the amps, voltage, draw etc.

The controller keeps cutting out randomly, so I have to keep pressing the reset button. I think it happens when I am using the water pump AND something else that is going through the controller, but it happens when the load is way below the 10amp max.

The controller came with the panel and is a cheap no-name brand but appears to be this one http://www.yoosmart.com/epip20-d-20a-solar-charge-controller-with-meter.html

I can replace the controller with something better if it is too sensitive, but I need to know if having the pump coming straight off the batteries is going to be a problem for any controller?

westbranch · March 2012

Re: problem with controller/regulator

can you do a test by rewiring it through the controller? I don't think that is the problem, is this while there is PV output?

Shadowcatcher · March 2012

Re: problem with controller/regulator

It would seem to me the better bet would be to bypass the controller for the load. It means giving up monitoring other than voltage from the panel to the battery but at least no cut off. One question do you know what the actual current load/amps are?

leaf · March 2012

Re: problem with controller/regulator

Having lived with a system that only monitors voltage and had no cutout, and having wrecked too many batteries, I'd rather buy a new controller than give up the ability to monitor load etc.

"can you do a test by rewiring it through the controller?"

Yes, but not easily.

"I don't think that is the problem, is this while there is PV output?"

It happens at night and during the day. The only pattern I can see is that there is some load going via the controller, even a really light load like a light on a 12V socket. If I have the mains switch off and use the pump (which is on a separate circuit), the controller doesn't cut out (I turn the mains back on and it's always good).

65DegN · March 2012

Re: problem with controller/regulator

I'm assuming that the 'mains switch' s a breaker of sorts. I would suggest disconnecting all loads except for the pump and reconnect them with only one load connected at a time, then operate the pump additionally and see what happens.

niel · March 2012

Re: problem with controller/regulator

in overview of what has been said it almost sounds as if the battery has been overdrawn of its capacity. 120w in pv is too low for the batteries that i can guess to be 220ah. now without knowing your specific daily load watthours you may be drawing far too much of that capacity with your loads without being able to keep up with a charge from solar.

leaf · March 2012

Re: problem with controller/regulator

"I would suggest disconnecting all loads except for the pump and reconnect them with only one load connected at a time, then operate the pump additionally and see what happens."

There is only one circuit on the house wiring at the moment. I run a double car type socket off that, and plug in either my laptop (6amps max I think), and/or my cell phone (.2 amps). Obviously if I use the pump (5amps) while the laptop is charging, the controller is going to cut out because it is more than 10amps. But I don't understand why it would cut out when only the cell phone is charging, or even nothing but the mains switch is on and there are some lights on the car socket (i.e. almost zero amp draw).

Also, using the pump doesn't cause the cut out immediately, I need to run it for a more than just a few seconds. Because the pump isn't via the controller I don't know what it's draw is at any given time, but the specs say 5amp max.

"120w in pv is too low for the batteries that i can guess to be 220ah. now without knowing your specific daily load watthours you may be drawing far too much of that capacity with your loads without being able to keep up with a charge from solar."

It's late summer here, and the batteries are showing fully charged every day. I'm not using much power, so I don't think this is the issue. Also, I'm pretty sure the problem started after I connected up the pump (several weeks after the house circuit went in)

vtmaps · March 2012

Re: problem with controller/regulator

To track this down you need some test equipment. A digital volt meter will tell you if you are hitting the low voltage cut off. The same meter can measure the amp draw of your pump, but you have to wire the meter in series with the pump. Better to have a clamp ammeter for that purpose. You can buy an adequate DVM for $25. A clamp ammeter can be had for about $60.
--vtMaps

BB. · March 2012

Re: problem with controller/regulator

Per Vtmaps suggestion--I suggest this Sears DC current clamp meter as a good entry level unit (I bought one too). It is "good enough" for most things needed here.

-Bill

leaf · March 2012

Re: problem with controller/regulator

I have a digital meter connected to the controller, and am pretty sure that the battery is not low on volts when this happens. I will test it though: wait until the battery is fully charged and then use the pump while the other circuit is in use with a low draw.

I'm confident that the amp draw of the pump is around 5 amps max, but will ask the installer to double check it.

problem with controller/regulator

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