MPPT Solar and Lithium Question

[wulfraat]

Originally Posted by wulfraat

Daleyocum - curious how you got your shunt to show up as the DC source on the Venus? I don’t see a differentiation between multiplus inverter DC load vs other DC loads in the trailer - l like the visibility you have in that you can distinguish between the two - I only see the total leaving the battery.

Were there special settings you did? It looks like your shunt is the only thing before the batteries which is how mine is setup.... so I’m wondering if perhaps I need to change a setting in the multiplus or perhaps update the shunt firmware....

ah - I believe you set "Has DC system" = YES in the Venus setup menu. I looked in the manual can you confirm?

[fran&frank]

Very cool daleyocum! I'm about ready to pull the trigger on a Venus GX. Can anyone tell me, if I connect to the Venus GX via wifi from my laptop will I be able to control or change settings on my Multiplus (connected to Venus via ve.bus) and mppt charger (connected to Venus via ve.direct)? Will I be able to update firmware on the Multiplus and mppt charger via my wifi connection to to the Venus? -- Frank

[wulfraat]

Originally Posted by fran&frank

Very cool daleyocum! I'm about ready to pull the trigger on a Venus GX. Can anyone tell me, if I connect to the Venus GX via wifi from my laptop will I be able to control or change settings on my Multiplus (connected to Venus via ve.bus) and mppt charger (connected to Venus via ve.direct)? Will I be able to update firmware on the Multiplus and mppt charger via my wifi connection to to the Venus? -- Frank

Unfortunately not. You still need to run VEConfigure application on a PC to change MultiPlus settings and flash to new firmware (v424 is the most current firmware for the MultiPlus 12/3000/120-50).

I was bummed when I figured that out - I’m a Mac user so I don’t even have a machine capable of connecting! (Mine was pre-programmed using settings from am solar)

I do hear that am solar are writing software to support a Mac interface to the multiplus though.....

[SilverHouseDreams]

Originally Posted by wulfraat

Unfortunately not. You still need to run VEConfigure application on a PC to change MultiPlus settings and flash to new firmware (v424 is the most current firmware for the MultiPlus 12/3000/120-50).

I was bummed when I figured that out - I’m a Mac user so I don’t even have a machine capable of connecting! (Mine was pre-programmed using settings from am solar)

I do hear that am solar are writing software to support a Mac interface to the multiplus though.....

I’m also a Mac user, you should be able connect the USB device to a virtual machine that has windows on it using VMware Fusion or Parallels. You could probably even use an unlicensed unactivated copy of Windows 8/10 for it....and it’s a one time thing, you can use a trial copy of Fusion or Parallels.

[wulfraat]

Good point... I even had VMware running Windows on my last Mac. Didn’t think of that... [emoji4]

[daleyocum]

Originally Posted by uncle_bob

Hi

If you are going "pure Victron" with the central control, why not put in a battery protect?

https://www.victronenergy.com/upload...--220-A-EN.pdf

If you take a look at the Battle Born spec sheet, it has a mighty wide range on the BMS low voltage cutoff. With all the smarts enabled, you can do a much better job with the BP-220. For storage, just rig a toggle switch in the control wire ... Switch is open = BP is open ...

Bob

I was just concerned about two different things trying to protect the batteries, since the Battleborns have it built in. Also I already had a Bluesea switch from another project so this saved $100.

[daleyocum]

Originally Posted by fran&frank

Very cool daleyocum! I'm about ready to pull the trigger on a Venus GX. Can anyone tell me, if I connect to the Venus GX via wifi from my laptop will I be able to control or change settings on my Multiplus (connected to Venus via ve.bus) and mppt charger (connected to Venus via ve.direct)? Will I be able to update firmware on the Multiplus and mppt charger via my wifi connection to to the Venus? -- Frank

As others have said, you’ll need a PC to flash the Multiplus. Just get some old PC at the Goodwill if nothing else. I used a 10 year old laptop running Windows 7.

Some of the things, like the solar charge controller and Battery Monitor, you can talk to via Bluetooth and your phone with a very nice interface. The Venus, sadly, wants to have you connect via WiFi to its hotspot and then you suffer through a emulation of what things would look like on the CCGX. It works and you have control over most things but it’s clunky. I am glad I have the Multicontrol panel to turn the inverter on and off and set its max shore current. It would be a pain to do on the Venus.

Victron has a lot of different products all developed at different times by different teams. Right now there are, in my opinion, too many communication protocols and too many interfaces/access methods. Once it’s set up it’s fine but doing so was a pain and I’m a pretty technical guy.

[daleyocum]

Originally Posted by wulfraat

ah - I believe you set "Has DC system" = YES in the Venus setup menu. I looked in the manual can you confirm?

Yep, that’s all it takes!

[fran&frank]

OK so to update firmware on my multiplus and mppt it sounds like I still need to connect directly from my PC to them using a ve.bus to usb cable and ve.direct to usb cable or bluetooth dongle, respectively. Was hoping if I connected to the Venus via WIFI I could do this thru the Venus without investing in the dedicated usb cables or blue tooth dongle. I know I need a ve.bus and ve dierct cable to connect them to the Venus. Thanks--Frank

[steverino]

Several years ago, I installed an AMSolar kit consisting of 300W of panel, MorningStar MPPT controller, and group 27 AGM batteries on my 27FB. I was super happy with the performance of the system, as it would usually be in float mode by early afternoon. If I added load during the day, ie fans, furnace, inverter, etc, the solar controller would flip back to MPPT mode and supply the current, as indicated by nearly zero amps flowing in/out of the batteries.

Thus, I'd reach sundown with 100% in the batteries. Fantastic.

Now, I'm planning the solar and battery upgrade on my new 30 Classic.

I've read in various threads that once the batteries are floated, some solar controllers need to detect about 5v differential between battery and panel output to start supplying current again, such as in the case above where I start adding load while the sun is still up. With panel peak outputs of 17.7v to 18v, and lithium floats of 13.6v or so, coupled with lithium's flat discharge curve, it's unclear to me whether the solar controller will pick up the load.

What's the experience of the good users of this forum for this case?

(edit) Looking at the Victron MPPT spec, I see that "PV voltage must exceed Vbat+5v to start".

Perhaps "start" is the event where the controller boots up, not when the control switches from float mode to charge mode. If so, I would not have a concern.

[uncle_bob]

Originally Posted by daleyocum

I was just concerned about two different things trying to protect the batteries, since the Battleborns have it built in. Also I already had a Bluesea switch from another project so this saved $100.

Hi

The Battle Born low voltage cutout is spec'd as "9.0 to 10.5V". There then is a note about "many converters need to see over 10V to charge". I take that to mean that they really may not cut out until 9V. That is taking each cell bank down to 2.25V.

They did some discharge runs against 12V batteries and there really isn't much capacity left at 12V. ( = you loose nothing with a 12V cutout)

https://battlebornbatteries.com/comp...teries-series/

Most published data suggests that 2.5V is the "may damage" point for these cells. At 12V you are well above that, at 9V ... not so much.

To me the $100 is pretty cheap compared to damaging a battery .... Yes, I have had things go flat. One of the repair guys left a switch on. I also camp a lot in the shade..

Indeed this *is* the flip side of the "max charge voltage" question. That still is ( at least to me ) an open issue.

Link to their video endorsing 14.6V all the time chargers:

https://battlebornbatteries.com/prog...tery-chargers/

Link to their video endorsing setting up for *not* 14.6V all the time:

https://battlebornbatteries.com/powe...po4-batteries/

( = that charger can run either in fixed output or multi-stage mode ).

So yes, just as on the "high voltage end" you can go several ways, there are ( at least to me ) multiple choices on the "low voltage end".

Bob

[daleyocum]

Originally Posted by fran&frank

OK so to update firmware on my multiplus and mppt it sounds like I still need to connect directly from my PC to them using a ve.bus to usb cable and ve.direct to usb cable or bluetooth dongle, respectively. Was hoping if I connected to the Venus via WIFI I could do this thru the Venus without investing in the dedicated usb cables or blue tooth dongle. I know I need a ve.bus and ve dierct cable to connect them to the Venus. Thanks--Frank

You are correct on the Multiplus needing the ve.bus to usb adapter. I found that device really fussy until I updated it’s firmware. Also one ve.bus port on the Multiplus seemed to work with it and one didn’t. Try and buy it from somewhere that has fresh stock to get the latest version of firmware on the adapter.

The Venus claims to be able to auto update over WiFi if you have a WiFi dongle plugged into its USB port. I didn’t happen to have one so I just put the firmware on a flash drive and plugged it into it’s USB port.

I didn’t need to update my MPPT controller so I haven’t figured that one out yet.

[daleyocum]

Originally Posted by uncle_bob

Hi

The Battle Born low voltage cutout is spec'd as "9.0 to 10.5V". There then is a note about "many converters need to see over 10V to charge". I take that to mean that they really may not cut out until 9V. That is taking each cell bank down to 2.25V.

They did some discharge runs against 12V batteries and there really isn't much capacity left at 12V. ( = you loose nothing with a 12V cutout)

https://battlebornbatteries.com/comp...teries-series/

Most published data suggests that 2.5V is the "may damage" point for these cells. At 12V you are well above that, at 9V ... not so much.

To me the $100 is pretty cheap compared to damaging a battery .... Yes, I have had things go flat. One of the repair guys left a switch on. I also camp a lot in the shade..

Indeed this *is* the flip side of the "max charge voltage" question. That still is ( at least to me ) an open issue.

Link to their video endorsing 14.6V all the time chargers:

https://battlebornbatteries.com/prog...tery-chargers/

Link to their video endorsing setting up for *not* 14.6V all the time:

https://battlebornbatteries.com/powe...po4-batteries/

( = that charger can run either in fixed output or multi-stage mode ).

So yes, just as on the "high voltage end" you can go several ways, there are ( at least to me ) multiple choices on the "low voltage end".

Bob

Good points about a dealer leaving the batteries on by mistake. I have alarms set at 12v so I doubt we’ll run the batteries down to their cutoff voltage while WE’RE using the trailer. The multiplus inverter is set to turn off at 12 volts so it would have to be a 12v load that the 500w of solar can’t keep up with.

I do want to keep to the 14.5v charge voltage Battleborn recommends until I hear otherwise.

[fran&frank]

daleyocum how did you get the firmware files you needed? I'm guessing if I don't have a bluetooth dongle or ve.direct to usb cable I can't verify what version firmware is on my MPPT 100/50? -- Frank

[daleyocum]

Originally Posted by fran&frank

daleyocum how did you get the firmware files you needed? I'm guessing if I don't have a bluetooth dongle or ve.direct to usb cable I can't verify what version firmware is on my MPPT 100/50? -- Frank

The files are on the Victron Professional site. You just make a free account.

My MPPT victron solar controller is the new SmartSolar version with built in bluetooth so I got the version info there. If you don’t have that but are plugging into the Venus with a ve.direct cable you should be able to get version info through that interface. I don’t think the non-bluetooth versions can handle a BT dongle AND a ve.direct connection at the same time easily.

[wulfraat]

If your Venus or CCGX is configured to send data to VRM Portal via your trailer's internet connection, you can also get device information via your account on vrm.victronenergy.com in the device section once you have selected your "site".

Example attached... handy!

[daleyocum]

Originally Posted by steverino

Several years ago, I installed an AMSolar kit consisting of 300W of panel, MorningStar MPPT controller, and group 27 AGM batteries on my 27FB. I was super happy with the performance of the system, as it would usually be in float mode by early afternoon. If I added load during the day, ie fans, furnace, inverter, etc, the solar controller would flip back to MPPT mode and supply the current, as indicated by nearly zero amps flowing in/out of the batteries.

Thus, I'd reach sundown with 100% in the batteries. Fantastic.

Now, I'm planning the solar and battery upgrade on my new 30 Classic.

I've read in various threads that once the batteries are floated, some solar controllers need to detect about 5v differential between battery and panel output to start supplying current again, such as in the case above where I start adding load while the sun is still up. With panel peak outputs of 17.7v to 18v, and lithium floats of 13.6v or so, coupled with lithium's flat discharge curve, it's unclear to me whether the solar controller will pick up the load.

What's the experience of the good users of this forum for this case?

(edit) Looking at the Victron MPPT spec, I see that "PV voltage must exceed Vbat+5v to start".

Perhaps "start" is the event where the controller boots up, not when the control switches from float mode to charge mode. If so, I would not have a concern.

It all seems to be fine with my five panels in parallel. Mine were pumping 25amps into the batteries on a random sunny NW afternoon. The Renogy panels seem to put out 19-20v consistently even on cloudy days. Victron would be in trouble if their chargers couldn’t charge Lithium batteries from a parallel arrangement!

[uncle_bob]

Originally Posted by daleyocum

Good points about a dealer leaving the batteries on by mistake. I have alarms set at 12v so I doubt we’ll run the batteries down to their cutoff voltage while WE’RE using the trailer. The multiplus inverter is set to turn off at 12 volts so it would have to be a 12v load that the 500w of solar can’t keep up with.

I do want to keep to the 14.5v charge voltage Battleborn recommends until I hear otherwise.

Hi

I switched my charger / converter over to multistage mode. It runs the way Battle Born recommends on one of the videos. When it drops down to 13.2V "float" voltage there is more than a bit of discharge from the batteries. I'll probably put it back to 14.4 ~ 14.6 at some point in the next few days.

The battery protect / disconnect can operate in an autonomous mode and cut out at any of a variety of voltages. It also can operate under command. The two are not mutually exclusive.

At this point I have two disconnects. One is the solid state gizmo that only takes out the battery bank. When it fires, the BMV and it are the only load on the battery. The other disconnect is a breaker that separates the (battery + solar + DC/DC ) from (converter + rest of trailer ). I've found both useful while (re)wiring this and that.

========

I also have no idea at all where the "must see 5V" thing comes from on the MPPT spec sheet. I routinely see 16V on the solar input to the device and 14.5 coming out of it. Unless my math is way off ... that ain't 5V . It *may* need to see a 5V delta to "wake up" at some point. If so I have yet to catch it sleeping ....

======

So has anybody checked the "usual entry points" to see how customizable the Venus is at the firmware level? It *should* all be standard Linux stuff .... Don't like that background color ... we can fix that ....

Bob

[steverino]

Originally Posted by uncle_bob

======

I also have no idea at all where the "must see 5V" thing comes from on the MPPT spec sheet. I routinely see 16V on the solar input to the device and 14.5 coming out of it. Unless my math is way off ... that ain't 5V . It *may* need to see a 5V delta to "wake up" at some point. If so I have yet to catch it sleeping ....

======

Bob

Bob, I'm not sure whether you are responding to my question about the 5v differential, but if so, it is mentioned at the bottom of the table on https://www.victronenergy.com/upload...-100-50-EN.pdf

It states "PV voltage must exceed Vbat + 5V for the controller to start. Thereafter, minimum PV voltage is Vbat +1V."

My initial assumption was that it needed to see PV > Vbat + 5v for it to transit to bulk/absorb mode from float. But it may be likely they are referring to initial start of the controller when PV voltage is first applied (like at daybreak). Indeed, when the system is up and running during the day, PV voltage will be > Vbat +1V, thus the transition from float to bulk/absorb should not be a problem.

So.... nevermind :-)

[uncle_bob]

Originally Posted by steverino

Bob, I'm not sure whether you are responding to my question about the 5v differential, but if so, it is mentioned at the bottom of the table on https://www.victronenergy.com/upload...-100-50-EN.pdf

It states "PV voltage must exceed Vbat + 5V for the controller to start. Thereafter, minimum PV voltage is Vbat +1V."

My initial assumption was that it needed to see PV > Vbat + 5v for it to transit to bulk/absorb mode from float. But it may be likely they are referring to initial start of the controller when PV voltage is first applied (like at daybreak). Indeed, when the system is up and running during the day, PV voltage will be > Vbat +1V, thus the transition from float to bulk/absorb should not be a problem.

So.... nevermind :-)

Hi

My observation is that the 5V applies the first time the device is powered up. Why it exists ... no idea. '

Bob