|
Post by blade3609 on Oct 29, 2018 17:55:32 GMT
Hello,
I have a Rover 40A mppt 2x strings of "2x100 watt in series" connected in parallel. The voltage is around 29-30V when optimally charging and 35V when not the battery is full or not optimally charging. Charging a 12V battery 200AH Inverter is connected, and devices are using about 40watts
Ive noticed since 2 days now that everyday at 9AM the panel voltage drops from 35V to 15volts for about 10 minutes and goes back to 29 volts, this expected behavior for the rover? I have not checked the voltage coming in with a meter yet. But since this is everyday at 9AM, it looks like the MPPT controller.
Any thoughts?
|
|
|
Post by tattoo on Oct 29, 2018 20:11:34 GMT
What kind of device do you have attached to the inverter? Does it run all the time?
That could be normal depending the draw....
How old is your system?
|
|
|
Post by blade3609 on Oct 29, 2018 20:56:08 GMT
Its currently just a switch with cameras and an NVR.
Im drawing 24/7 40 watts, at start of day the batteries are drained to about 12.3-12.2 volts. At around 1 PM i see the system charged the battery completely and it changes to FLOAT charge
my system is 2 months old.
|
|
|
Post by tattoo on Oct 29, 2018 21:13:26 GMT
I think your battery is getting a little old but that's normal.... Since it's first thing in the AM when the battery is only at 12.2 it's lowest and since it's floating in the afternoon.... I would keep an eye on it but I wouldn't worry over it....
|
|
|
Post by blade3609 on Oct 29, 2018 21:55:54 GMT
A little old? The battery is barely 2 months old .
At exactly 9AM the panel voltage drops from 35V to 15volts for about 10 minutes and goes back to 29 volts. How does the battery influence that ? It looks maybe like a rover test ?
the battery is holding its charge quite well over night. From <5 PM - 7.30 AM , with a draw of 40 watts / 12.~ = 3+ A , lets say with losses 4+ amps
12.3 is about 65 % .. 0.65 x 200AH = 130 AH, that means about 70 AH used in 14.5 hours.
|
|
|
Post by tattoo on Oct 29, 2018 23:09:20 GMT
A little old? The battery is barely 2 months old . LOL I'm sorry I read it was 2 years old... LOL
|
|
|
Post by tattoo on Oct 29, 2018 23:16:24 GMT
A little old? The battery is barely 2 months old .
At exactly 9AM the panel voltage drops from 35V to 15volts for about 10 minutes and goes back to 29 volts. How does the battery influence that ? It looks maybe like a rover test ?
the battery is holding its charge quite well over night. From <5 PM - 7.30 AM , with a draw of 40 watts / 12.~ = 3+ A , lets say with losses 4+ amps
12.3 is about 65 % .. 0.65 x 200AH = 130 AH, that means about 70 AH used in 14.5 hours.
Yes I agree your battery is holding voltage very well... And is sized just right for your usage... You don't want to let your battery get below 50% draw down....
You could be right about your rover test.. But I haven't run across that happening on either of my systems....
|
|
|
Post by tattoo on Oct 29, 2018 23:19:42 GMT
I just thought of something.... Do you have a tree or something shading your panels at 9am? And then the Sun is above it letting full Sun again?
|
|
|
Post by blade3609 on Oct 30, 2018 1:33:52 GMT
There are no trees nearby.
I find it very odd too, I haven't noticed this drop before.
During the voltage drop the charge current is 5 -6 A, after the drop it jumps all the way to 14 A.
Do you think it could be a bad panel? or just the MPPT calibrating itself to start charging higher currents?
|
|
|
Post by blade3609 on Oct 30, 2018 1:43:01 GMT
Here is a graph i compiled of the charge current. (on the left its x10 to get Amps)
|
|
|
Post by tattoo on Oct 30, 2018 2:56:32 GMT
Here is a graph i compiled of the charge current. (on the left its x10 to get Amps)
What is the angle of your panels? The graph looks like what my panels do... That looks normal for this time of year, the time of day and the angle of the sun...
|
|
|
Post by blade3609 on Oct 30, 2018 3:24:12 GMT
My panels are facing north, but are pretty flat almost horizontal.
This is the voltage drop from today
This is the voltage drop from yesterday
|
|
|
Post by Admin on Oct 30, 2018 8:57:08 GMT
Hello, I have a Rover 40A mppt 2x strings of "2x100 watt in series" connected in parallel. The voltage is around 29-30V when optimally charging and 35V when not the battery is full or not optimally charging. Charging a 12V battery 200AH Inverter is connected, and devices are using about 40watts
Ive noticed since 2 days now that everyday at 9AM the panel voltage drops from 35V to 15volts for about 10 minutes and goes back to 29 volts, this expected behavior for the rover? I have not checked the voltage coming in with a meter yet. But since this is everyday at 9AM, it looks like the MPPT controller.
Any thoughts?
Hello, Based on your responses, we have gathered that there are no trees nearby and that the drop seems to happen around the same time for both of your graphs. During this time, do you have a load that could be "activated" at this time period? It does seem peculiar that it happens round the exact same time. Also, what is your general location? -Renogy Team
|
|
|
Post by blade3609 on Oct 30, 2018 11:44:37 GMT
There is no extra load that is activated at that time. Just a constant 40 watt usage from the switch and NVR.
Im located in Curacao, which is in the Caribbean.
|
|
|
Post by bupkis on Oct 30, 2018 12:22:13 GMT
hi blade3609, sure looks like a controller glitch! controller is tracking Vmp up to ~36v while the sun is rising. Controller then decides Vmp of 15v is appropriate, why, that is the question. Then it keeps using that low Vmp for some period of time, odd.
When reported panel V drops from ~36 to 15 I'd expect the currest to take a similar drop, it does not. Current does stay low as the sun rises then jumps when 30v Vmp is acquired.
|
|