Solar voltage help...

NinerBikes wrote:

BFL13 wrote:
Niner,

..." My unit at 120 watts is 3/4 the output that his is. I have seen, at most, 6.62 amps out of mine,on the charge/load side, measured by one of those RC battery charge meters with 4 readings on the screen."

When I had a 120w panel, its Isc was 7.6a and sure enough that's what I got at the batteries as seen on the Trimetric. You need to aim the panel at a high enough sun, disconnect the controller, and take the Voc and Isc on the panel's wires using a multimeter. It is under 10a so that will not fry the meter in amps setting.

You then hook it all back up and see what the amps is at the battery. If not close to the Isc you got, you have wiring issues

Your panels are poly crystalline, the OP's are mono crystalline. They are not as efficient.

my panel

Readings at 34.0 N in Late Oct 2013.

Seems I got 6.84 Amps/hr at peak, sometime during the charging regime, if only briefly with these pulse chargers. Isc is rated at 6.98, on the back of the panels. Perhaps I lost some being the sun was so low that late in the year.

5 feet from controller to battery of 12 gauge wire, rated at 20 amps, at under 7 amps, is not a loss issue. I kept everything as short as possible during these beginning trials, to minimize losses.

Are we talking about the same panels? According to this, you Imp is 6.98 You should be getting Isc.

http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2756/W-Solar-120-Watt-Foldable-12-Volt-Solar-Panel/product_info.html

Play with the sliders on here--You are just under the STC on 25 Oct at 34N

http://pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation

BFL13 wrote:
Niner,

..." My unit at 120 watts is 3/4 the output that his is. I have seen, at most, 6.62 amps out of mine,on the charge/load side, measured by one of those RC battery charge meters with 4 readings on the screen."

When I had a 120w panel, its Isc was 7.6a and sure enough that's what I got at the batteries as seen on the Trimetric. You need to aim the panel at a high enough sun, disconnect the controller, and take the Voc and Isc on the panel's wires using a multimeter. It is under 10a so that will not fry the meter in amps setting.

You then hook it all back up and see what the amps is at the battery. If not close to the Isc you got, you have wiring issues

Your panels are poly crystalline, the OP's are mono crystalline. They are not as efficient.

my panel

Readings at 34.0 N in Late Oct 2013.

Seems I got 6.84 Amps/hr at peak, sometime during the charging regime, if only briefly with these pulse chargers. Isc is rated at 6.98, on the back of the panels. Perhaps I lost some being the sun was so low that late in the year.

5 feet from controller to battery of 12 gauge wire, rated at 20 amps, at under 7 amps, is not a loss issue. I kept everything as short as possible during these beginning trials, to minimize losses.

OP said earlier he got 21v at input and output of controller when batts not connected, so Voc on panel wires into the controller was 21v. This means they are in parallel. In series it would be more like 42v.

If it is too difficult to get a replacement controller from the seller, it is simple to get another from ebay. While waiting for that to arrive you can still use the solar on panel-direct. Just unhook it during the day if batts get past 14.8v and also before dark (in case the diode is in the controller) then hook up again in the morning.

You only really need a controller for when you will be away from the rig when it is likely to go up past 14.8. If that happened when using panel direct after I fried a controller one time, I would shut it off and then reconnect after getting back such as when going swimming in the afternoon and voltage was getting up there. Ease of mind to unhook it before going away.

I'd pull the cover on the junction box on the right, and check the wiring inside, to see if some idiot wired it in series, instead of in parallel. Should be red to red and black to black for all 3 wires, for them to all be wired in parallel.

If they are all wired in parallel, then the controller is suspect.

I just keep thinking with the panel connected first the controller is in 24 volt mode.

Disconnect the panel. Connect controller to the battery. Reconnect the panel. Check battery voltage.

Does OP's controller have temperature compensation? If so, it would get pretty darn hot on the backside of the panel, wouldn't it?

Niner,

..." My unit at 120 watts is 3/4 the output that his is. I have seen, at most, 6.62 amps out of mine,on the charge/load side, measured by one of those RC battery charge meters with 4 readings on the screen."

When I had a 120w panel, its Isc was 7.6a and sure enough that's what I got at the batteries as seen on the Trimetric. You need to aim the panel at a high enough sun, disconnect the controller, and take the Voc and Isc on the panel's wires using a multimeter. It is under 10a so that will not fry the meter in amps setting.

You then hook it all back up and see what the amps is at the battery. If not close to the Isc you got, you have wiring issues

OregonTRX4 wrote:

Tom_M wrote:

OregonTRX4 wrote:
Measured at batteries. It is disconnected.

What is "It"? Was the voltage measured at the battery when everything was connected? It would be impossible for the battery to measure 16.55 if it is disconnected and very unlikely even when connected unless the battery is bad.

With everything connected it starts at 13.93 and ramps up to to 16.xx before I disconnect the solar from the batteries. Batteries measure 12.6 shortly after panels are removed. It is doing this on multiple batteries. The input to the controller and output to the batteries measure about the same at 21.xxV at the controller. So is it most likely the controller is bad? I tried connecting batteries to controller then controller to solar and it made no difference. This is what I have http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2754/W-Solar-160-Watt-Foldable-12-Volt-Solar-Panel/product_info.html

Sounds like you got a bum controller, send the controller back to Solar Blvd and have them send you another unit.

BFL13 wrote:

NinerBikes wrote:
..........

10 amps is plenty with that 160 watt set of panels. It starts out at 22V and gets down to 18V in the specs, and is capable of putting out 8.88 amps,max, if the battery will even allow that kind of charge take......
.

Niner the Isc on that is 9.46a which he should get with the panels pointed at a high sun. You are using the Imp figure which is meaningless with PWM.

10 amps on two 6s is 5 amps per battery, which is the acceptance rate for about 90% SOC at 14.5v. So there should be no trouble finding time from 50-90 SOC for the battery bank to accept the 9.46a

Also after 90% and amps taper, you can run things that take from the solar--any amps over what the battery is taking up to what the panel can do at the time.

Eg, good time to recharge/use the laptop late afternoon while the panel can still do 9a when pointed, batts taking 3 amps, inverter with laptop load taking 6 amps

http://www.solarblvd.com/Solar-Panels-&-Systems-12-Volt-Solar-Panels/c1_269/p2754/W-Solar-160-Watt-Foldable-12-Volt-Solar-Panel/product_info.html

Controller says 10 Max amps on the Load side, or the charge side. Controller cuts about 5% of the amps from the input side from the panels as losses. Output from the controller is 8.8 amps Max, for 160 watts. ON the load or charge side.., My unit at 120 watts is 3/4 the output that his is. I have seen, at most, 6.62 amps out of mine,on the charge/load side, measured by one of those RC battery charge meters with 4 readings on the screen.

So... 8.8 amps on the load or charge side is about all those panels will make, coming out of the charge controller. My guess is that they can make 9.2 to 9.3 amps coming in from the panel to the charge controllers, with the monocrystalline panels in this brand of solar panels/chargers.

OregonTRX4 wrote:

NinerBikes wrote:

OregonTRX4 wrote:
I just connected my solar kit (160w cmp12 controller)and the voltage while connected to the rv batteries reads 16.55v. Is this normal or too high? Sorry but im new to this.

Please take a picture of the wiring you are using at the back end of the panel, where the solar controller is located, and post it up here.

As requested.

Unscrew the charge controller and make a note if there is an amp rating of the controller either on the sides or underneath, if removed. There should be a tag somewhere stating the amp rating. Might be a 15 amp unit, or possibly a 10 amp unit, seeing as they are mono crystalline panels.

Provide the info to Solar Blvd on the charge controller, and have them send you another one out to replace yours, and be done with it.