Charge controller stops when i turn on my inverter

[halfhourearly]

i have my 20A 12V charge controller working fine to charge my battery but when i turn on my inverter the CC seems to stop charging. They are both connected to the correct battery terminals and the inverter displays 13.2V. Before i switch on the inverter the CC 12V output was 17.2V which is as i expected. once the inverter is on i read flickering V values from 0 - 3V all over the place.

Please help. Thanks

[inetdog]

i have my 20A 12V charge controller working fine to charge my battery but when i turn on my inverter the CC seems to stop charging. They are both connected to the correct battery terminals and the inverter displays 13.2V. Before i switch on the inverter the CC 12V output was 17.2V which is as i expected. once the inverter is on i read flickering V values from 0 - 3V all over the place.

Please help. Thanks

Tell us more about the model of CC you are using.
I would not expect the output of any CC to be 17.2 volts when set up for a 12V battery. Was that a typo? AHA! I see now that you have corrected it to 13.2. Much more reasonable.

If you are leaving the solar PV input connected and disconnecting and reconnecting the CC to the battery you are probably never getting it initialized properly.
Most (although not all) CCs specify that you MUST connect to battery first and then to PV.

If that is not your problem, then I suspect that you have something miswired.

[PNjunction]

Also, what is your battery, inverter, and what are you trying to power from it?

[halfhourearly]

You were right on. I needed to turn on the inverter first. Does this mean that when a load change on my invert causes my battery V to drop that my inverter would lose the connection (I will try). Also, i have a 1000W Motomaster pure sine wave inverter with remote. The remote is not much use if i have to go rest the invert each time anyway.

3 - 48W home built panels
Approximately 6.6V each in series
20A MPPT Charge controller
1 New Deep Cycle 12V Battery
Motpmaster 1000W pure sine wave inverter
Testing with 100W 120V Flood light

Thanks for all the help and suggestions you can offer

[inetdog]

You were right on. I needed to turn on the inverter first. Does this mean that when a load change on my invert causes my battery V to drop that my inverter would lose the connection (I will try). Also, i have a 1000W Motomaster pure sine wave inverter with remote. The remote is not much use if i have to go rest the invert each time anyway.

3 - 48W home built panels
Approximately 6.6V each in series
20A MPPT Charge controller
1 New Deep Cycle 12V Battery
Motpmaster 1000W pure sine wave inverter
Testing with 100W 120V Flood light

Thanks for all the help and suggestions you can offer

If your CC (not inverter, right?) goes crazy each time you turn on the inverter one of two things is happening:

1. You have a very bad, high resistance, connection to the battery, or
2. Your battery is just not big enough to work properly with this inverter. You will have the same problem of excess voltage drop when you put a large load on the inverter.

In general a 12V system is not suitable for anything larger than a 600W inverter. 300W would be even better.

[PNjunction]

1 New Deep Cycle 12V Battery

* What is the manufacturer / model and ah capacity rating?
* Is it truly new and has it ever seen a full charge yet, say from an ac charger? Hint: you'll want a charger eventually.
* Note that "new" from some dealers merely means new-old-stock that may have been sitting around self-discharging and sulfating for a few years. Seeing if the battery will truly charge from a stable source will help weed out any issues before you start.

Testing with 100W 120V Flood light

With the inverter inefficiency thrown in, you are pulling more than 10A continuous from the battery - or at least trying to before the inverter shuts down with the voltage crashing.

If you are just testing lighting, then definitely go for a CFL or perhaps an LED flood from GE or Sylvania for a 100w "equivalent". That usually means about a 1/3 to 1/4 the wattage for the same amount of light. Nearly any home-improvement store should have a wide selection - even my local grocery store stocks the GE LED's amongst all the CFL's.

Right now without even thinking about your solar array, we may have a big mismatch between your battery's capacity rating, and the load you are trying to pull. Also throw in a possible "deficit charge" scenario, pulling out more than you can put back in and never reaching a full charge....