Solar panel and IBS battery monitor query

[wuntenn]

Another update - Beat Wyss the founder and owner of IBs sent me this:

Hi John,
you definitely need a single battery solar regulator. If charge voltage on aux has reached 13.3V (if enough charge is available) IBS links automatically to main battery, hence both batteries receive now charge at same time. If solar charge drops off sometimes when batteries drop to 12.9V IBS is splitting the batteries again.
IBS is not a battery charger and not regulating any charge. If enough charge is there it links, if no charge is available anymore it separates. The solar regulator or the alternator regulator are regulating the available charge.

You need a solar cell (maybe around 80W) and a Solar regulator with single output with at least 6A feeding into aux battery.

Please let me know if I can be of any assistance.
best regards
Beat

So that's the bottom line.

 

[wuntenn]

Quick query from an electrical novice - I'm now at the preparation for installation of the various bits for my solar panel set up in my 110.

The Morningstar controller has a set of outputs for 'LOAD' and I need some confirmation that I'm correct in assuming I may connect my Engel fridge to them. The instruction book is not entirely helpful, making the assumption the reader has some knowledge of the various connection methods, and the device itself shows a bulb icon on the LOAD terminals.

The controller data sheet states a 30amp load current, which I'm sure the fridge will not exceed (?).

Or is there any advantage to connecting the fridge to the battery?

The charge controller has a Low Voltage Disconnect, and I'm thinking that it's probably better to connect via the controller so the fridge can be disconnected automatically should the battery get below the LVD threshold (11.4V).

Am I right in this?

 

[unseenone]

Good question, one I asked myself when I went to install. I am actually going to start putting together some kits I think, with all the bits necessary. You do not HAVE to connect to the load side, you can also run it directly from the battery. The up side of connecting on the load side, is that you will be able to see how much you are drawing at any given side if you wire to the load connector. Here's a picture of how I envision it being set up ideally.

http://www.disco3.co.uk/gallery/displayimage.php?album=35750&pos=4

Note the "load" side powers the power pole. In the power pole is the low voltage disconnect, which I am using on an APRS (ham) tracker. You can use something like that for a fridge as well. I haven't quite worked on a slick panel/mount, so no special pictures of that yet. You will note on this installation, the two marine outlets are wired directly to the battery and fused on both positive and negative at the battery, as with the supply for the solar connector. The solar controller is also connected direct to the battery and the load side to the power pole, which charges the aux battery as well.

My small Engel draws 2.5 amps. I think it is best to do a large enough run to avoid voltage drop as much as possible. I would consider a 30-40amp run, then you don't have to change wire later if something changes. Your solar panel may put out 5amps or more, so total so far, let's say 3+ your anticipated solar amp current. As a general rule, if you are putting in a 30amp charger, it would be good to run wire rated for 30-40 amps. How long will the run be to the battery? Controller to outlets?

 

[wuntenn]

Ok thanks that's useful, there's more to this than simply sticking in some wires and pressing the GO button!

So if I understand your setup the LVD is external to the Prostar controller. Presumably to allow you more flexibility in cut-off voltage levels.

My battery to Prostar cable run is 6 feet and panel to controller is around 10 feet. I'm having to site the panel at the rear of the lifting roof because of other considerations - the location of roof boxes and carrying of other stuff which would be problematic if I had the panel on the front of the roof a couple of feet nearer the controller.

I think kits would be a good idea, certainly helpful for the novice installer.

 

[unseenone]

OK... Do not worry about the controller to the panel wire length, you could easily have a 25' cable for that and have no trouble. 6' is very short run, depending on what your max amperage you settle on, 30-40 you can use AWG 8 or AWG 6. I really like marine flat cable for these projects because it has an additional protective cover, and is very flexible. Here is the distance size chart. You can order this on Amazon, marine sales outfits, etc. in longer lengths, or I could cut a piece off of the rolls I buy and sell it to you. http://www.marinco.com/en/resources/wire-data/three-percent-voltage-drop

Yes, the switch is programmable for cut off voltages, in my case, it only switches on when the vehicle is running, but you can program it for the cut off voltage you want. Here is a link to the switch. It is important to note that Anderson connectors are used. I can make you're Anderson cables if you want, I have all the crimpers. You can also order custom cables with the ends and wire the size you want online, but it won't be marine flat cable. Still it will be good cable and well made.

Here is a decent battery side fuse harness, available with various ends, pictured is how I have it. http://www.powerwerx.com/fuses-circ...line-fuse-holder-ring-terminals-10-gauge.html

Here is the cut off switch you see pictured http://www.aprsworld.com/apo3/
The APO3 is designed for 12 volt vehicle electrical systems with negative ground. It can switch up to 20 amps and carry up to 30 amps. The shutdown voltage can be set to one of four pre-programmed voltages (11.8, 12.1, 12.7, 13.05 volts) using two DIP switches; the shutdown delay can be set to one of four pre-programmed times (0, 5, 10, 20 minutes). The device is housed in a sturdy ABS plastic case.

Here you can order custom made cables with Anderson connectors, etc. http://www.powerwerx.com/adapter-cables/design-build-your-own-custom-cable.asp

If it is possible, keep the ends on your MC4 cable. That way you can disconnect it. You can buy short ends to install in the charge controller, then if necessary you can disconnect easily with no loose cables floating around with voltages in them. It also would make it easier if you wanted to add more panels on occasion. As pictured, you see the cables, not the ends, they're about 8" long, with MC4's on them.

 

[wuntenn]

That's great information thank you. Appreciate the cable offer but it's likely to cost more for delivery across the Atlantic than the cable cost! I can source most of this stuff in the UK I'm sure. This is a great help thanks - doing electrical stuff is easy, but doing electrical stuff right is far from straightforwards!

 

[geordie4x4]

Hi wuntenn,
I have also been re-doing the wiring for my battery system and have come across many of the same issues discussed through this thread.

If the IBS unit that you have is one of the more recent models, then as their web page states, it is dual sensing (or as they say "bi directional"). i.e it is sensing the voltage at both batteries and will connect if charge is being applied to the starting battery from the alternator or charge to the auxillary battery from a solar pannel (older units did not do this, they only sensed the starting battery).

Regarding cable yes I can confirm that even with a 100W pannel and only 5.6 A, it is better to go with bigger cable than 6mm2 (I used 8 AWG or B&S = 8.4mm2) to reduce the voltage drop. I have also found it is beter to have the solar charge regulator closer to the battery. I have tried a Morningstar 12 which was mounted at the panels on the roof. But this dropped the voltage at the source then there was further voltage drop over the length of the cable to the battery. I have now changed to run the solar panel voltage of 17 to 18V all the way to the regulator near the battery and I get much higher charging voltage.

 

[wuntenn]

Hi wuntenn,
I have also been re-doing the wiring for my battery system and have come across many of the same issues discussed through this thread.

If the IBS unit that you have is one of the more recent models, then as their web page states, it is dual sensing (or as they say "bi directional"). i.e it is sensing the voltage at both batteries and will connect if charge is being applied to the starting battery from the alternator or charge to the auxillary battery from a solar pannel (older units did not do this, they only sensed the starting battery).

Regarding cable yes I can confirm that even with a 100W pannel and only 5.6 A, it is better to go with bigger cable than 6mm2 (I used 8 AWG or B&S = 8.4mm2) to reduce the voltage drop. I have also found it is beter to have the solar charge regulator closer to the battery. I have tried a Morningstar 12 which was mounted at the panels on the roof. But this dropped the voltage at the source then there was further voltage drop over the length of the cable to the battery. I have now changed to run the solar panel voltage of 17 to 18V all the way to the regulator near the battery and I get much higher charging voltage.

Hi Geordie - thanks for your input. I'm a bit confused over the IBS functions - mine is over ten years old, and the literature that came with it states:

"The monitor displays the stored energy of both batteries and the charge voltage when charging them with an alternator, a solarpanel or any other source. The batteries are automatically linked for charging and isolated when discharging."

....so I'm not sure if your observations re "older models" refers to my unit - do you have any idea if there are identifying model numbers or pre/post serial numbers or production dates to differentiate 'older' from 'more recent' ones?

My recent email to IBS elicited a response (quoted previously) that did not mention the solar linking function being particular to specific models.

Thanks for the cable info - always good to get 'real world' advice rather than theoretical. How "close to the battery" do you now have the controller?

Thanks.

 

[unseenone]

Simply put--

When the auxiliary battery gets below a certain voltage, the aux battery and the main battery are separated. When you charge your aux battery, and it goes above the separation voltage, it reconnects, charging both the aux battery, and the main battery. Keep in mind this is not a perfect system, but it is what it is. This is how most of the battery separators work.

 

[wuntenn]

Simply put--

When the auxiliary battery gets below a certain voltage, the aux battery and the main battery are separated. When you charge your aux battery, and it goes above the separation voltage, it reconnects, charging both the aux battery, and the main battery. Keep in mind this is not a perfect system, but it is what it is. This is how most of the battery separators work.

Thanks - I'm curious about Geordie's comments re the older/newer IBS units functions. If in fact there is some difference in the charging methods between recent models and 'original' ones. Hard to tell from the IBS literature what model iterations there are. Of course it may be that they ALL do the charging 'thing' pretty much the same, but that the later models are more accomplished. I guess I;ll find out when I wire it all up!

 

[geordie4x4]

To clarify my understanding of it, I had an IBS unit (branded TJM) in my previous vehicle (about ten years old now).
As far as I know, it only sensed the charge voltage from the main battery so would only connect both batteries when the main battery saw alternator voltage over 13.7 and with the ignition switched on, or accessory.
When I connected a battery charger or solar to the auxillary battery and with the ignition switched off, it did not connect and charge the main battery. It would only connect with the ignition on. So not sure if that was just the model or an issue with the way the unit was set up.

With my new vehicle, I have a USI-160 amp unit from Traxide-RV. It senses the voltage from both batteries which is what I also believe the new IBS units do. So this means when I have solar to the auxillary battery or the charger, it will also connect and charge the main battery.

 

[wuntenn]

Thanks Geordie - I'm still not sure at all - but I'm sure I'll find out when I wire it all up and can get a meter on the batteries. It's definitely NOT like plumbing, this electrickery!

 

[geordie4x4]

Have fun. I am a biologist not an electrician but have gradualy worked out a few things by trial an error and by reading good ideas on these forums.

With the charging and IBS you may only need to change which battery you connect the solar to.
The preference:
If it will connect when the solar charge is to the auxillary battery then that would be the preference as that is the battery you are running power from. That way when there auxillary battery is charged and if the fridge is not drawing more than the solar panel, then there is excess charge and the IBS will connect to the main battery and also be charging it too.
The less preferable option:
If (like my old unit was wired) it will not connect both batteries with the solar on the auxillary, then you can wire the solar to the main battery. That way it will always have the main battery completely charged and only be connecting to the auxillary when there is adequate incomming charge (voltage over the trigger point which I think was 13.7 from memory). But this way is less preferable as the bulk of the solar charge is not always going to the auxillary battery where you are drawing your power. This option will work if you have a lot of solar panels producing more power than your fridge etc are drawing. But not so good if you have minimal solar power, high power use and cloudy days.
So try it the first way and see if it is working.

 

[wuntenn]

Thanks Geordie. Well it's confusing.......the solar controller is a good one rather than a cheapo, it's a Morningstar ProStar 30. After reading up on all this stuff it became obvious that (like in many areas) you get what you pay for, and the Prostar got great reviews and I found it for 1/4 of RRP, so a good deal.

The plan is to connect the solar to the Aux battery. However as the Prostar has a 'LOAD' circuit my plan is to attach the Engel fridge directly to it, rather than to the battery, and the Prostar will run off solar/battery, and if the battery voltage goes below the LVD (Low Voltage Disconnect) level it will switch supply to the fridge off automatically. My understanding is that this coupled with the IBS functions to (potentially) charge both batteries (assuming sufficient juice) should give me the best charging scenario and a safety net.

 

[unseenone]

+1 on the Traxide +1 PS30 as well as the way you describe setting it up. It works well, even with a ham radio. I added a Powerpole to my setup, that adds USB charging.

I have a picture of that setup, the Traxide setup, etc. under solar and Traxide.