Thanks @RandyP , but the question is why this panel push more than 24.1V and the other question is how can I lower this to 24V?
Renogy DC DC Charger w/ MPPT
- Thread starter Will Prowse
- Start date
I tried the DCC30S in my trailer and it was awful. So much so that I am returning it and replacing it with a Victron Energy SmartSolar 75/15 and Orion Smart Tr 18.
I wired in the 100W panel on the trailer and pulled up the 12V wire from the 7-pin connector to feed into the DCC30S. First problem is that it did not seem to charge me battery effectively off the solar. I suspect the problem is that the MPPT SCC would be more effective if I could wire a pair of 100W panels in series to boost the voltage, but that is not possible because the DCC30S is, for some inexplicable reason, only rated for a PV voltage of 25V.
The second problem was that the bluetooth app for monitoring/controlling the unit is utterly useless. It reports solar voltage, current and watts - except that the numbers do not match (W = VI, unless one is using a Renogy). It also does not report what is going on with the battery charging - meaning it does not report what phase of the charge cycle we are in, and again the volts, current and watts numbers do not line up. In terms of the DC-DC charger, it doesn't even have a section for reporting on that. Instead it has a "Load" section - but that only applies to SCC's that have PV, battery and load ports. I do get numbers showing up in the "Load" section when I connect my TV, but they make no sense. Possibly it is reporting how much current the DCC30S is trying to drive to my car's battery, but that is certainly not the information I would be looking for there (I would want to know how much power is going from my car to the trailer's battery).
Fortunately, I bought this from Lowes and they will accept returns, so it is going back as soon as I replace it with the Victron Energy units.
I wired in the 100W panel on the trailer and pulled up the 12V wire from the 7-pin connector to feed into the DCC30S. First problem is that it did not seem to charge me battery effectively off the solar. I suspect the problem is that the MPPT SCC would be more effective if I could wire a pair of 100W panels in series to boost the voltage, but that is not possible because the DCC30S is, for some inexplicable reason, only rated for a PV voltage of 25V.
The second problem was that the bluetooth app for monitoring/controlling the unit is utterly useless. It reports solar voltage, current and watts - except that the numbers do not match (W = VI, unless one is using a Renogy). It also does not report what is going on with the battery charging - meaning it does not report what phase of the charge cycle we are in, and again the volts, current and watts numbers do not line up. In terms of the DC-DC charger, it doesn't even have a section for reporting on that. Instead it has a "Load" section - but that only applies to SCC's that have PV, battery and load ports. I do get numbers showing up in the "Load" section when I connect my TV, but they make no sense. Possibly it is reporting how much current the DCC30S is trying to drive to my car's battery, but that is certainly not the information I would be looking for there (I would want to know how much power is going from my car to the trailer's battery).
Fortunately, I bought this from Lowes and they will accept returns, so it is going back as soon as I replace it with the Victron Energy units.
Thanks @ekarlson . I have the DCC50S witch this review is about and it work well by managing my main battery and the 50ah lifo, secondly.
Yoûre right about the Renogy BT app, it is terrible and hard to understand for a beginner like me and their customers service is sooo slow/bad/non existing!!!
To get back at my problem, do you have any ideas why the pv input voltage would be over the 24.1v (bad panel?) or how to lower it for the DCC50S to manage it?
thanks
mkaye
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not sure what battery you are talking about
it will only charge your engine battery from the PV connection when the house battery is considered fully charged
if you mean the house battery, then it should charge based on the profile selected
it's an MPPT controller, which means it has a built-in DC-DC converter - it will boost the incoming voltage to what is required by the profile
you say you have 100W solar on the trailer, but are playing with the 12V on the 7-pin connector - not sure why you think they are related
the 12V pin should be coming from your vehicle alternator and you would connect it to the ALT terminal (if you wanted the DCC30S battery profile and wanted to limit current from the alternator)
solar connected to PV
the DCC30S can only report what current is flowing through it i.e. from PV/ALT connections to battery
it has no idea how much total current is flowing in or out of the battery, since there may be other charging devices and discharging
if you bought it for that, then you bought the wrong device i.e. you need a shunt and monitor to know what is happening at the battery
@mkaye Regarding charging the TV's battery, yes, that is what the Renogy docs say, but the bluetooth app is terrible and it is impossible to verify what is actually happening. I do know that the trailer's battery did not seem to be charging properly while I was towing this weekend so it should not have been trying to charge my TV's battery at all.
In terms of MPPT, the PV's voltage has to exceed the battery's voltage before it engages (at least, that is the documented behavior for the Victron SmartSolar MPPT - harder to tell with the Renogy because the documentation is rather lacking in details).
In terms of the 12V from the 7-pin, that is the alternator input to the DCC30S. They are "related" because the DCC30S is supposed to favor the solar input and only draw from the alternator input when the solar input is insufficient. There is also then a relationship because according to the Renogy docs, if the trailer's battery is full, then the PV input ends up directing power back down the alternator input to charge the TV's battery.
In terms of monitoring, yes, I know that the DCC30S can only report energy flowing through it. What I am saying is that, at least via the bluetooth app, one cannot tell what energy is flowing through the Renogy unit.
In terms of MPPT, the PV's voltage has to exceed the battery's voltage before it engages (at least, that is the documented behavior for the Victron SmartSolar MPPT - harder to tell with the Renogy because the documentation is rather lacking in details).
In terms of the 12V from the 7-pin, that is the alternator input to the DCC30S. They are "related" because the DCC30S is supposed to favor the solar input and only draw from the alternator input when the solar input is insufficient. There is also then a relationship because according to the Renogy docs, if the trailer's battery is full, then the PV input ends up directing power back down the alternator input to charge the TV's battery.
In terms of monitoring, yes, I know that the DCC30S can only report energy flowing through it. What I am saying is that, at least via the bluetooth app, one cannot tell what energy is flowing through the Renogy unit.
mkaye
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since there is no ALT ON signal (unless a smart alternator), the Renogy uses the voltage at the PV terminal to know when the engine is running i.e. > 13.2V
it has no bearing on the DC-DC converter and the voltage sent to your battery - the profile decides that
i have the Renogy unit in my RV, installed last Friday
i tested everything out and it works as advertised
i.e. i had my 200W solar suitcase connected to PV and was getting ~14A - max for this time of year
i fired up the RV and got 29A - the full 15A (max allowed) from the alternator + the 14A from solar
if i had more than 15A from solar, i still would only get 30A max when the alternator was supplying current
i couldn't check if i could get more than 14A from solar w/o the alternator as i don't have enough solar
should be able to get the full 30A from solar in that case
the BT2 app worked fine showing me actual current flowing from both sources & voltage of each battery
once my LFP battery was full i got 7-8A flowing back to my engine battery (RV off)
it was weird tho, when charging the engine battery from solar, it was showing current flowing from the alternator, instead of the other way around, but it was charging my engine battery & it would charge the battery for few minutes and then quit for a minute & start charging again
i ignore any of the other numbers because i have a Chargery BMS & Bogart monitor that tell me SOC
@mkaye I was *not* talking about voltage going to the trailer battery. I was talking about required *input* voltage from the PV to engage the MPPT charging cycle. In the Victron docs, it states "The controller will operate only if the PV voltage exceeds battery voltage (Vbat). PV voltage must exceed Vbat + 5V for the controller to start. Thereafter minimum PV voltage is Vbat + 1V." So the MPPT, at least for the Victron MPPT, does not even turn on until the PV voltage has exceeded the Vbat by 5V. I know - that is weird and is not at all how I understood MPPT to operate, but that is what the Victron docs state. I do not know whether the Renogy unit has the same logic as the Renogy documentation is lacking on technical details.
As for the Renogy BT app, it doesn't even have a panel for monitoring the alternator *INPUT*. It has a panel for "LOAD". I can only assume that what is reported there is *OUTPUT* from the Renogy to the TV's battery, which really is not that useful. Also, as you noted, even interpretting those numbers as OUTPUT from the Renogy to the car's battery, the numbers did not really make sense. But my main point is that what it does *not* report is *INPUT* from the alternator - I cannot tell how much current it is drawing from the car to charge the trailer's battery.
As for the monitoring in the "SOLAR" panel of the app, it reports volts, amps and watts - except that the numbers do not line up. I was monitoring it the other day and it was reporting 18.1V, 0.63A and 41W from the solar panel. Now, unless I've forgotten how to multiple, those numbers do not make sense.
Regarding ALT ON, I tried it both ways - (1) letting the Renogy decide that the car was on by monitoring the voltage and (2) wiring a signal to the ALT ON to tell the Renogy that the car was on. In neither case was there any way to monitor from the bluetooth app whether the Renogy was *DRAWING* power from the car or not. As I said, the app only has a "LOAD" panel and the only way the numbers reported there made any sense was if they were reporting OUTPUT from the Renogy to the car - INPUT from the car to the Renogy was not reported anywhere.
As for the Renogy BT app, it doesn't even have a panel for monitoring the alternator *INPUT*. It has a panel for "LOAD". I can only assume that what is reported there is *OUTPUT* from the Renogy to the TV's battery, which really is not that useful. Also, as you noted, even interpretting those numbers as OUTPUT from the Renogy to the car's battery, the numbers did not really make sense. But my main point is that what it does *not* report is *INPUT* from the alternator - I cannot tell how much current it is drawing from the car to charge the trailer's battery.
As for the monitoring in the "SOLAR" panel of the app, it reports volts, amps and watts - except that the numbers do not line up. I was monitoring it the other day and it was reporting 18.1V, 0.63A and 41W from the solar panel. Now, unless I've forgotten how to multiple, those numbers do not make sense.
Regarding ALT ON, I tried it both ways - (1) letting the Renogy decide that the car was on by monitoring the voltage and (2) wiring a signal to the ALT ON to tell the Renogy that the car was on. In neither case was there any way to monitor from the bluetooth app whether the Renogy was *DRAWING* power from the car or not. As I said, the app only has a "LOAD" panel and the only way the numbers reported there made any sense was if they were reporting OUTPUT from the Renogy to the car - INPUT from the car to the Renogy was not reported anywhere.
@mkaye Ah, just heard back from the Victron people - the trick is that when the MPPT is not engaged, the PV sees this as an "open circuit" and so the panel's Voc applies (which is generally north of 20V). So as long as the PV's Voc > Vbat+5V, then the MPPT will engage.
Also note - MPPT does *not* boost voltage. I went back to check the places I had seen references to this and it seems that those discussions assumed a DC-DC converter interposed between the panels and the MPPT. The MPPT by itself does not boost voltage.
Again, no idea whether this is how the Renogy works due to the lack of technical specifics in the docs. Since the DCC30S does have a DC-DC converter for the alternator input it is unclear whether that DC-DC converter is also used for the PV input.
Also note - MPPT does *not* boost voltage. I went back to check the places I had seen references to this and it seems that those discussions assumed a DC-DC converter interposed between the panels and the MPPT. The MPPT by itself does not boost voltage.
Again, no idea whether this is how the Renogy works due to the lack of technical specifics in the docs. Since the DCC30S does have a DC-DC converter for the alternator input it is unclear whether that DC-DC converter is also used for the PV input.
Renogy DC Home is some sort of "community" app - seems to require a login to a cloud service so I'm not certain how one would use this with a non-internet connected system. For monitoring/controlling the unit in an RV what Renogy directed me to was the Renogy BT app, which is what I am (trying) to use for my setup. Connects to the Renogy via bluetooth and kinda, sorta reports status and allows some degree of configuration.
Both apps have fairly horrible reviews in the Android store (2/5 for the Renogy BT and 1.7/5 for the DC Home). Renogy BT seems to be the more widely used app (10K downloads vs 1K).
Both apps have fairly horrible reviews in the Android store (2/5 for the Renogy BT and 1.7/5 for the DC Home). Renogy BT seems to be the more widely used app (10K downloads vs 1K).
RandyP
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Unfortunately Renogy BT app is no longer supported by Renogy.
The DC Home app does not recognize my DCC50S skew number as a DC-DC controller, so It does not work to provide 'user' setpoints on the device. Renogy SNAFU if you ask me.
If the Renogy BT app is unsupported (I cannot find anything one way or the other) and the DC Home app is the only choice, this only cements my decision to return the Renogy unit and go with Victron. The DC Home app seems to require some sort of login before one can do anything with it. Given that none of the campgrounds that I have been at over the last 2 years have had any cell phone reception that is a full-stop blocker (cannot login because no internet connection, meaning no ability to manage my unit that is sitting right in front of me when I am out on the road). Hopefully the place I bought this thing from will still accept the return...
RandyP
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A BT device app that can connect with Renogy social media, but not required to.
TopSpinQuark
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On paper the Renogy DCC30S looks exactly like the product I'm looking for, but a number of posts/threads here make me leery of ordering one.
Just to make sure I've got it all straight (as of April 2021):
1) When using the "LI" battery type setting it will never drop down to a float voltage. This can be "fixed" by using a BT-2 and selecting the "User" battery type and entering custom voltages. However, the "User" battery type setting allows for charging below freezing (the "LI" setting does not)?
2) The charging current can be limited using the BT-2. Normally the charging current can be (for the DCC30S) up to 30A solar, or up to 30A alternator, or up to 15A for either when both are supplying power. Has anyone tested to see if, when the charging current is software limited, the 50% limits when both inputs are active remain at 50% of the rated power, or change to 50% of the software limited power? ie: If I set the charge current limit of a DCC30S to 20A, can I still charge at 15A from the alternator if solar is supplying 5A? Or would I now be limited to 10A from each input when both are supplying power?
3) The PV input is limited to 25V. I noticed (just a few posts up) Plalonde is trying (unsuccessfully) to use the 40 cell Renogy 200W panel which has a rated open circuit voltage of 24.1 - looks like he is actually getting 26~27 volts and the charger is rejecting it? Has anyone been able to successfully use a 40 cell panel? Looks like people have had luck with 36 cell panels earlier in this thread.
4) The BT-2 and associated app(s) leave a lot to be desired. From what I read the hardware occasionally needs power cycling and the software is buggy and missing features. For my purposes I would only use the BT-2 to set/change parameters so as long as it worked reliably enough for that I wouldn't really care.
5) I think someone said on one of these threads they thought their DCC50S? slowly drained their starter battery. Has anyone else had any starter battery draining concerns?
Ultimately the DCC30S is still appealing because it is relatively cheap, combines two devices in one, and allows charge current limiting. I could live with the other limitations if I could just set it up and leave it in the corner for the next five years while it did its thing.
An alternative I am considering is a Victron Smart 12/12-18 DC-DC charger (and a separate MPPT controller), but I have a similar limitation to sunrise in this thread: https://diysolarforum.com/threads/dc-dc-charger-current-limiting.19885/ - if the Victron had a way to set an absolute (or any) current limit I'd probably just get one.
Other suggestions for similar devices that allow charge current limiting (at least from the alternator side) would be most welcome.
Just to make sure I've got it all straight (as of April 2021):
1) When using the "LI" battery type setting it will never drop down to a float voltage. This can be "fixed" by using a BT-2 and selecting the "User" battery type and entering custom voltages. However, the "User" battery type setting allows for charging below freezing (the "LI" setting does not)?
2) The charging current can be limited using the BT-2. Normally the charging current can be (for the DCC30S) up to 30A solar, or up to 30A alternator, or up to 15A for either when both are supplying power. Has anyone tested to see if, when the charging current is software limited, the 50% limits when both inputs are active remain at 50% of the rated power, or change to 50% of the software limited power? ie: If I set the charge current limit of a DCC30S to 20A, can I still charge at 15A from the alternator if solar is supplying 5A? Or would I now be limited to 10A from each input when both are supplying power?
3) The PV input is limited to 25V. I noticed (just a few posts up) Plalonde is trying (unsuccessfully) to use the 40 cell Renogy 200W panel which has a rated open circuit voltage of 24.1 - looks like he is actually getting 26~27 volts and the charger is rejecting it? Has anyone been able to successfully use a 40 cell panel? Looks like people have had luck with 36 cell panels earlier in this thread.
4) The BT-2 and associated app(s) leave a lot to be desired. From what I read the hardware occasionally needs power cycling and the software is buggy and missing features. For my purposes I would only use the BT-2 to set/change parameters so as long as it worked reliably enough for that I wouldn't really care.
5) I think someone said on one of these threads they thought their DCC50S? slowly drained their starter battery. Has anyone else had any starter battery draining concerns?
Ultimately the DCC30S is still appealing because it is relatively cheap, combines two devices in one, and allows charge current limiting. I could live with the other limitations if I could just set it up and leave it in the corner for the next five years while it did its thing.
An alternative I am considering is a Victron Smart 12/12-18 DC-DC charger (and a separate MPPT controller), but I have a similar limitation to sunrise in this thread: https://diysolarforum.com/threads/dc-dc-charger-current-limiting.19885/ - if the Victron had a way to set an absolute (or any) current limit I'd probably just get one.
Other suggestions for similar devices that allow charge current limiting (at least from the alternator side) would be most welcome.
You can download the Victron Connect app and use it in Demo mode. I haven't, but it's been suggested by others.
mkaye
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see my post above https://diysolarforum.com/threads/renogy-dc-dc-charger-w-mppt.1406/post-249864
i don't see anywhere in the app to limit the current
as far as i can tell the LI profile has no float voltage
i don't see anywhere in the app to limit the current
as far as i can tell the LI profile has no float voltage
TopSpinQuark
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There was some talk of it a few pages back, including a screenshot here: https://diysolarforum.com/threads/renogy-dc-dc-charger-w-mppt.1406/post-206712
Does the ignition need to be on ??Okay! Renogy called back. Here is a synopsis of the questions I ask and their answers.
Q1. Can a AGM or FLA battery be use as the starter battery and lithium as the house battery?
A1. Yes, no problem. Just don’t mix FLA, AGM and lithium together while on the same charger circuit.
Q2. How can I charge the house battery with shore or AC power?
A2. Connect house battery charger circuit to the +/- terminals on the starter battery. Get a inexpensive but quality battery charger and mount/connect it to the starter battery in the engine compartment. Plug it in, when the starter battery hits the correct voltage it will start charging the house battery via the Renogy DCC50S.
Q3. how do I tell if my alternator is a smart alternator or a regular alternator?
A3. Just hook it up without a smart alternator wire, if it works then you don’t have a Smart alternator. It will not harm anything. "Or use RandyP’s suggestion above."
Q3. In lieu of the worldwide "Beer Virus" should Renogy customers, after coming in contact with their products, sanitize or sterilize external extremities as well as their internals components with alcohol based liquid refresh... I mean... products?
A3. While the Renogy CS Rep apprised me that his was not a medical opinion the answer was . . . "Why not?” Beer was his preferred product as it hydrates while sanitizing.?
p.s. Recently Renogy has moved all of its workers to home-based work and their new phone system is not acting properly.
TopSpinQuark
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So I did get a DCC30S (& BT-2). Have not installed it yet but have been playing with the setup. I can confirm it does let you limit the charge current in the Renogy DC Home app.
The two Android Renogy apps (Renogy BT & Renogy DC Home) allow you to change different settings - Renogy BT seems to have more voltage settings, but only Renogy DC Home lets you adjust the charge current.
I had no problems connecting with either app, on multiple Android devices. I'm not planning to use the apps / BT-2 for anything but setup.
Renogy BT:
Renogy DC Home:
I'm not so sure the additional settings in the Renogy BT app actually do anything - they seem to be for a different product.
For some strange reason Renogy calls the absorption stage "boost" but I can live with it.
The two Android Renogy apps (Renogy BT & Renogy DC Home) allow you to change different settings - Renogy BT seems to have more voltage settings, but only Renogy DC Home lets you adjust the charge current.
I had no problems connecting with either app, on multiple Android devices. I'm not planning to use the apps / BT-2 for anything but setup.
Renogy BT:
Renogy DC Home:
I'm not so sure the additional settings in the Renogy BT app actually do anything - they seem to be for a different product.
For some strange reason Renogy calls the absorption stage "boost" but I can live with it.
