I need more power Scotty!

Another somewhat simple question for those of you with a 700/702 and Victron MPPT. Do you generally wire the battery side of the MPPT directly to the battery or do you wire the negative to the shunt and the positive to the battery?

Nevermind, I was able to answer my own question. I wired the negative from MPPT to the shunt and 700 is now displaying incoming current. I got my Bluetooth dongle in today and tested out the whole system with my cheap Allpowers 100W panel and was getting between 3.5-4a consistently. Should fit my needs perfectly! Thanks for all of the assistance!

badtoytrd said:

I got my Bluetooth dongle in today and tested out the whole system with my cheap Allpowers 100W panel and was getting between 3.5-4a consistently.

Click to expand...

Got mine all set up too. Ridiculously easy and the app is awesome! I was getting nearly 9a in the afternoon parked under a large tree (that hasn't leafed out yet)!

Short update.

The system has been working super well, so didn't have much to say here. I decided to "test" the system by disconnecting the solar panels yesterday at noon, and turn the fridge on "cold" and the fan on high, to see what the drain was like.

After 13 hours on two hot days -- 30*C in Calgary -- the batteries are at 64%, having consumed 103 of 220AH capacity.



Note also the battery voltage is below 12 V even though 12.2 V is considered "50%".




The battery status is 64%. Why the discrepancy?

This is because there is draw/load on the batteries. Take that away and let it "settle" and it will pop up to over 12.2v. This is why you can't just use a volt meter to tell what condition your batteries are in... you need a battery monitor that can track AH consumed.

Next picture: - Notice the difference in time remaining and current draw? One shows 6.4A draw and the other only 2.6A. 2.6 is just the Fridge. The overhead fan adds another 3.8A (I think i got that the right way around!).



Time remaining changes radically based on draw too.

Last picture is 90 minutes later, charging off the 265W panel on the roof, parked a slight angle away from the sun. Fan is off, but fridge is running.



I'll check at sundown to see how we did after 6 hours of charging in fading (smoke filled) daylight.

That Victron looks pretty cool. Do you have to use an MPPT with it or can you use a PWM?

either

Adding to this. The skies were very smoky this afternoon by 3 pm from fires in the Banff and further west into BC. However, we had hit 76% SOC after just 3 hours of charging, but now the panels were down to 1 Amp, not so good.



So I fired up the truck and connected the batteries together.



43.7A going over the shunt in my engine bay to the 2g wire leading to the camper batteries, truck engine is idling. (13.36*43.7 = 583.8W)

I've got some gauges and controls in the truck cab too, so this shot is of the battery Voltage output (14.13V) from the alternator, (switch facing down) and the current flow.



This one is of the battery voltage at the camper batteries after going 20' over 2g wire (13.48V)




Voltage drop at 50A is about 0.65 V

This corresponds pretty good to the voltage drop calculated here - but note I ignored the "one way" suggested length and made it a loop distance of 40', as I believe Rando has insisted is needed elsewhere on this forum. Thanks Rando!

Vic,

Here is the question I sent you via PM. I will let you paste your reply in so others can see it.


Vic,

I am a little confused about the VIctron contoller and Battery monitor and hoping you can help clarify things for me.

I now have an MPPT 75/15 controller and a BVM-702 battery monitor in my camper.

I want to be able to monitor both the Solar Controller (panels) and the batteries via bluetooth. I assume that I need to buy and connect a ve direct smart dongle to the MPPT 75/15 and another dongle to the BVM-702 in order to read both of them from my iphone.

The 75/15 controller and the BVM-702 monitor each have only one ve direct port. If I use a bluetooth dongle on either or both devices they cannot communicate/share information with each other.

Question 1) Do I need two dongles to do this or can I use one (without switching it from device to device)

Question 2) Will the Victron application on my iphone connect and provide information from both dongles or do I have to disconnect and connect for each dongle?

Question 3) Do I lose any functionality by not connecting the 75/15 to the BVM-702 via the ve direct cable?

Thanks,

Craig

I overlooked the MPPT display and did not buy one but if I go with a dongle, as I understand it, I could not use it anyway as the dongle will occupy the only ve direct connection port on the MPPT 75/15.

I ordered a second dongle today.

Regards,

Craig

Vic Harder said:

This corresponds pretty good to the voltage drop calculated here - but note I ignored the "one way" suggested length and made it a loop distance of 40', as I believe Rando has insisted is needed elsewhere on this forum. Thanks Rando!

Click to expand...

Download the Blue Sea app CircuitWizard http://circuitwizard.bluesea.com/

It works a little differently as it is designed for wire size calculation. It asks for round trip length.

You will get incorrect results by not using the requested single or round trip length.
Btw, with CircuitWizard, and your current and length, it recommends 2 gauge wire (assuming I entered the values correctly

I, also have "Voltage Drop" by J J Fowler on the iPad. It asks for one way length.

Paul

I asked my questions of Victron and I got a prompt reply - from the Netherlands. Great support!

Craig,

To monitor both units at the same time you need a color control panel.
If you buy one dongle you can connect from one to the other to monitor both units.
If you don’t want that you have to indeed buy two Bluetooth dongles.
Once connected to a dongle with your i-phone it will recognize it.




With best regards,

[SIZE=10.5pt]Jan Klumpenaar[/SIZE]
[SIZE=10.5pt]Sales Manager[/SIZE]
[SIZE=10.5pt]Victron Energy BV[/SIZE]
[SIZE=10.5pt]Phone:+31365359700[/SIZE]
[SIZE=10.5pt]Fax :+31365359740[/SIZE]
[SIZE=10.5pt]Mobile:+31653115367[/SIZE]
[SIZE=10.5pt]Skype:janklumpenaarvictronenergy[/SIZE]
[SIZE=10.5pt]jklumpenaar@victronenergy.com[/SIZE]
[SIZE=10.5pt]www.victronenergy.com[/SIZE]



P.S. Using two dongles is far cheaper than buying the Color Control Panel. Dongles are about $50 ea and the Color Control Panel is about $500.

ckent323 said:

Question 1) Do I need two dongles to do this or can I use one (without switching it from device to device)

Question 2) Will the Victron application on my iphone connect and provide information from both dongles or do I have to disconnect and connect for each dongle?

Question 3) Do I lose any functionality by not connecting the 75/15 to the BVM-702 via the ve direct cable?

Thanks,

Craig

Click to expand...

Good questions Craig! You should ask them over on the "More power scotty" thread too. I will paste this reply in there if you do.
http://www.wanderthe...-scotty/page-23


3) Long answer short - you don't connect the two. While it would make INFINITE sense to do so.
2) I don't have two BT dongles, but yes, my understanding is that you can have two talking to one phone ( I think this is determined by how many devices your phone can pair with)
1) I only have the BT dongle on my BMV. All three can be programmed/monitored from the display units.... ah wait -
- did you buy the MPPT Control display for your MPPT 75/15?
- http://shop.pkys.com...rol_p_4356.html

Vic

Vic, et al,

It seems that I have made an error in my solar panel/controller panel connections but I am not seeing it.

Here is my installed configuration:

I have installed the MPPT 75/15 with a VE.direct dongle. I have also installed a BVM-702 with Temp sensor and VE.direct dongle.

My solar panels (two 100 Watt 18.9V 5.49 A panels connected in parallel) are connected to the PV in terminals of the [SIZE=12pt]The MPPT 75/15 controller[/SIZE][SIZE=12pt]. [/SIZE]

I checked the polarity at the terminal block (see attached picture) that is between the panels and my MPPT 75/15 and I believe the polarity is correct (I used red wires for + and black wires for -)

The red wire from the terminal block is connected to the MPPT 75/15 PV + and the black wire is connected to the MPPT 75/15 -.

The neg pole of my battery is connected to the "battery only" side of the shunt that came with the BVM-702. MPPT Batt - is connected to the other post of the shunt.

The MPPT Batt + is connected through a manual reset 40A circuit breaker and a BlueSea battery selector to the positive terminal of my battery (yes I am aware of the discussion around if this is needed or not but I don't think it is the root of the problem).

My battery comprises two 6V Deep Cycle AGM 200 Ah batteries connected in series for a 12 V, 220 Ah battery bank.

The shunt is also connected to the BVM-702 display using the cable supplied with the display.

The camper load from the IOTA distribution panel is connected to the battery + and - posts (the camper already had an FWC installed IOTA DLS-30 30 Amp , 12 v Power Converter/Charge Controller along with an IOTA DLS-IDP-30 30 Amp AC/DC Distribution/Fuse panel - to which the camper loads are connected e.g. refrigerator, lights, etc).

The system from the battery to the camper load was working just fine before the addition of the solar charger and panels so I do not think there is any issue on that side of the circuit.

The temp sensor is connected to the shunt and appears to be connected correctly as I am able to see the temp on the VE connect display on my iphone.

Problems:

Using the VE connect ap only volts are displayed for the MPPT 75/15 (both watts and amps are zero) and only volts and temperature are displayed for the BVM-702 amps are zero).

The LEDs on the MPPT are both on. The blue LEDs on both dongles are blinking. The BVM-702 display shows volts and temperature but 0 for amps



By the way I did turn on lights and fans but saw no current draw in the VE.Connect display screens only voltages.







This should be easy but I am not seeing the problem.


Request/Question:

I would appreciate it if you would look at the attached images and advise any problems you see.


Regards,

Craig

You haven't connected the shunt correctly. The ONLY thing connected to your battery negative should be the shunt. Everything else (charge and loads) connects to the other side of the shunt from the battery.

rando,

Thanks for catching that. I moved the camper negative from the battery neg terminal to the shunt and the BVM-702 is now reading the loads through the shunt. It shows the battery at 12.67 V.

However, the MPPT controller is still showing 0 watts and 0 amps. It is displaying 0 watts 20.7 V for the panels and displays 13.6 V but 0 amps for the battery. It also says it is in float mode.

I do not understand why even when I have loads on and the BVM-702 shows a couple of amps the MPPT is not reading any current or power.

It seems that the battery is not actually being charged. I am now wondering if the switch is the problem.

While I wait for your reply I will bypass the MPPT positive line around the switch and circuit breaker and go direct to the battery to see if that does the trick.
yed on my iphone


Addendum: I checked the voltage at the MPPT controller "PV in" connections with a voltmeter and it is as displayed on my iphone - solar panels = 19.77V but it shows zero watts.

I checked the output from the controller at the "BATT +/- terminals and that is also as displayed on my iphone Battery = 13.67 V but amps are zero.

I checked the voltage from the shunt "battery only" side to the battery positive terminal and it is 12.66 V. I checked the voltage from the other side of the shunt to the battery positive terminal and it is 12.66 V.

I checked each battery - one is 6.31 V rthe other is 6.35 V = 12.66 V.

The controller shows float mode and also shows the batteries at 100%.

I am expecting that when I turn on a 2 amp draw on the batteries that I would see current flow from the solar panels to the batteries when monitoring the MPPT controller. But it shows zero amps and zero watts all the time.

I do see current flow displayed on the BVM-702 when the load is applied so I know what the load is.

I am now wondering if the shunt in the MPPT controller only works for the load output and I cannot see if current is flowing to the batteries if the load is not connected directly to the MPPT controller. I need to read the manual again I guess.


Regards,

Craig

Craig,

1) The MPPT can only show a load if you have the load connected to the load terminals.

2) I don't understand the purpose of that switch.

3) Are the solar panels in the sun?

4) If your batteries are at 100%, there is no need for the charger to apply power to the batteries. I've had my camper in full sun and watched the gauges as I turn the fan off and on. With no draw and the batteries at 100%, the PV output reading will be essentially zero. Turn on a heavy draw and the PV output pops up in order to meet the demand.

5) You won't see anything load related on the MPPT until you connect the load there - see #1

6) Good!

7) Bingo!

8) It takes a bit of getting used to indeed!

ckent323 said:

1) I do not understand why even when I have loads on and the BVM-702 shows a couple of amps the MPPT is not reading any current or power.

2) It seems that the battery is not actually being charged. I am now wondering if the switch is the problem.

3) I checked the voltage at the MPPT controller "PV in" connections with a voltmeter and it is as displayed on my iphone - solar panels = 19.77V but it shows zero watts.

4) The controller shows float mode and also shows the batteries at 100%.

5) I am expecting that when I turn on a 2 amp draw on the batteries that I would see current flow from the solar panels to the batteries when monitoring the MPPT controller. But it shows zero amps and zero watts all the time.

6) I do see current flow displayed on the BVM-702 when the load is applied so I know what the load is.

7) I am now wondering if the shunt in the MPPT controller only works for the load output and I cannot see if current is flowing to the batteries if the load is not connected directly to the MPPT controller.

8) I need to read the manual again I guess.


Regards,

Craig

Click to expand...

Vic and rando - Thanks for your comments.


I plugged my camper into shore power last night to get the refrigerator cooled down I used the switch to disconnect my solar charger from the batteries as a precaution.

As soon as I pulled out the red master switch on the camper (OEM with the IOTA equipment) I saw that the BVM-702 shunt was reading +25 Amps and 13.6 V or so. That made me wonder if the solar panels and controller are actually working. I watched and did see the current slowly roll down to 18 A so maybe the IOTA charger with IQ-4 is using a different charge profile?

However, I thought about the multi stage charging and and I wonder if the IOTA DLS-30 even with the IQ-4 is charging the batteries correctly. I do not understand why the Solar controller shows the batteries 100% charged and in float at 12,66 V and then when I plug into shore power the IOTA starts putting 25 amps in the batteries at around 13.6 V


Sanity check - As I wrote above my camper has an OEM IOTA DLS-30 30 Amp, 12 v Power Converter/Charge Controller along with an IOTA IDP-30 30 Amp AC/DC Distribution/Fuse panel.

That system was connected to a battery bank comprising two 6 V FLA deep cycle batteries connected in series. There were only two cables connected to the battery bank from the IOTA setup. A positive wire and a negative wire.

I simply added my solar setup replaced the old FLA batteries with two new lifeline 6v AGM 220 Ah batteries and connected to the AGM batteries as shown in my wiring diagram.

Now I am wondering about connecting the loads to the MPPT controller so I can convince myself the Solar charger is doing what it is supposed to be doing.

It is my belief that in order to connect my loads to the MPPT controller that I would have to add another set of wires and reconfigure the IOTA distribution panel wiring so that one pair of wires connects only the loads to the MPPT controller and another set of wires come from the IOTA power converter/charger directly to the batteries. That would prevent the load input of the MPPT controller from ever seeing the output of the Power converter/Charge controller (I think this is why rando decided not to connect to the load side of the MPPT controller).

Anyway does it make sense that the IOTA charger is puting much more current into the batteries as compared to the Victron Solar Charger?


Regards,
Craig

The fact that your solar controller thinks thats 13.66V at the battery terminals, but your battery bank is 12.66V is worrying. I am going to guess your problem is with that combiner switch - which I don't see the purpose of, and may cause you problems. Have you disconnected the charge controller from the batteries with solar panels attached? This would likely not be good for the charge controller as it won't be able to detect the system voltage and could possibly damage it. Like Vic, I would suggest removing the switch. Then reset the whole system by disconnecting the solar panels, connect the controller back to the batteries and reconnecting the solar panels.

rando,

You and Vic have convinced me that the switch is unnecessary at a minimum and I am going to remove it and then follow your other suggestions. Hopefully I have not caused any permanent damage to the MPPT controller.

Thanks for commenting on this.

Regards,

Craig

ckent323 said:

rando,

You and Vic have convinced me that the switch is unnecessary at a minimum and I am going to remove it and then follow your other suggestions. Hopefully I have not caused any permanent damage to the MPPT controller.

Thanks for commenting on this.
Regards,
Craig

Click to expand...

Rereading your description - the fact that you see different voltages at the MPPT controller battery terminals and at the battery indicates that there is not a good connection between the two - which would explain what you are seeing. I noticed in your photo that the circuit breaker on the battery line is also switched off - I assume you switched that on for testing.

Craig,

Another thought: Have you configured the MPPT for your batteries? Set the right voltages, charging profile, etc? If you have not already found a data sheet for those particular batteries with the bulk/float/tail current settings, that makes a big diff in the lifetime of your batteries.

The IQ-4 uses a generic AGM charge profile. If you are reading that much current coming from the IOTA to your batteries, the are NOT charged up.

And 12.6V (without a load on them - fully settled) isn't fully charged anyway. Something is amiss.

I have a much smaller AC-DC charger (Genius 7200) and it is wired right to the batteries (negative does go through the shunt though) and have plugged it in at the same time as the solar is charging and the alternator is feeding the batteries. They don't conflict and the BMV-702 keeps track of the battery status.