Panels producing 14a but only showing charging as 8a

Joined
Oct 30, 2016
Posts
1,710
Likes collected
3,565
Location
Colchester
Funster No
45,854
MH
Hymer BMC t780
Exp
On 4th van so not a total newbie....
We now have 2x 160w zamp panels, and the original 130w that was on the van, so a total of 450, the zamp controller shows we are producing about 14a, which seems about right, about 200w, but the read out in the van shows the battery is charging at about 8a, so it looks like we are losing about 6a, am I missing something here? Why is the full 14a not going into the battery?
 
I'm no expert but I think if the batteries are charged the amps reduce and go to zero when fully charged ?
Mine seem to anyway
 
Are your batteries getting to fully charged, there will be nowhere for the amps to go if they are full.

Martin
 
Currently showing about 85%, dies it still use the onboard charger, could that be limited to 8/9a?
 
We now have 2x 160w zamp panels, and the original 130w that was on the van, so a total of 450, the zamp controller shows we are producing about 14a, which seems about right, about 200w, but the read out in the van shows the battery is charging at about 8a, so it looks like we are losing about 6a, am I missing something here? Why is the full 14a not going into the battery?
What else is turned on? you can only ever really rely on a dedicated shunt based battery computer to get an accurate assessment of what is actually happening

In this instance my take would be 14 from the solar, using 6, battery getting 8!

This may not be the case as van read outs are notoriously inaccurate, as we don't know the state of charge etc, but it would explain things

This is one of the reasons that we don't sell solar regulators with readout displays, the information is misleading

Subscribers  do not see these advertisements

 
This seems to be answered now but are you sure you are not mixing amps and volts, as in full sun mine always reads 14 volts but only 4 amps ,one 100w panel.
Feel free to knock be back if I am wrong.
 
Previously I just had the 130w panel, I then seemed to be "losing" up to 1a drain, now with nothing else on the drain seems to have gone to about 6a? Satellite/humax turned off, so just the usual systems monitoring drain.
 
The solar controller will use power to run even if it’s charged your batteries, it might go to standby when it’s dark and use less.
Is the controller mppt or pwm.
Good controllers also limit the current depending on the temperature and state of charge as said by others
 
Unfortunately it's a pwm controller, but should the charge as shown by the van be about 6a less at 85%? I need to see what it does at lower state of charge, but the weather has been so good here, it is charging to 100% by mid afternoon quite easily despite only putting in 8a.
 
Presume your panels are in series.
If they are the amps will be the same but the voltage will add together.
Parallel will add the amps but keep the voltage the same.

Both have their advantages depends on your setup.
Have a look at the alt-e store channel on YouTube they explain the whole solar thing very well in an easy to understand way.

A PWM controller will pull the panels down to the voltage of the battery bank I.e. 12 volt nominal so you don’t get the full power from them.
Every system will have losses due to cable size, connections, resistance etc.
A MPPT controller will run the panels at their max amps and volts and convert the extra voltage to amps.

For example when I acquired my panel a couple of years ago a 30.7 volt 255 watt 8.45 amp from memory at best conditions open circuit, I actually got about this when I tested it even on a crisp sunny day at 10am in March.
I didn’t believe a door size chunk of silicone and glass could produce power from just sunlight.
My Votronic 350 mppt controller converts the voltage down to what ever the battery needs (depending on charge state) and ups the amps so the batteries get the max from the system.
I’ve had over 10amps when experimenting running the fridge on battery/solar.

Most mornings both hab and starter Batteries (both lead acid) are recharged by 11am even in winter, although all my lights are led and our power use is what I would say is minimal.
My hab battery has a sticker on it 2014 so it could be coming to the end of its life but it’s still going strong.

Subscribers  do not see these advertisements

 
Sounds totally incorrect to me. Both should read the same current regardless of regulator type or length of wiring unless there is a draw of 6A by van equipment . So either one is grossly inaccurate or is faulty. The only way to be certain is to measure the current with a meter of known accuracy. The only possibilities (other than inacccuracy) are that you are misreading controller volts as amps or that something in the van is using the difference in amps.
 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Back
Top