Renogy DCC50S charging issue

[ScottRoz]

This is helpful! Thank you. I will check out Will's videos as well.

I have the battery type set to SLA at the moment and it seems to be working, but I can try removing the temp sensor from the charger and setting it back to Lithium to make sure it's set up appropriately.

I think that the Lithium charging will use a higher voltage than the setting for SLA, so it will be good to get that resolved. Otherwise you may not reach the full capacity of your batteries.

 

[John Frum]

I think that the Lithium charging will use a higher voltage than the setting for SLA, so it will be good to get that resolved. Otherwise you may not reach the full capacity of your batteries.

https://www.renogy.com/content/RBC50D1S-G1/RBC50D1S-Manual.pdf
page 22.
SLA charge profile has higher cc/cv voltage

 

[ScottRoz]

The temperature sensor on the charger is for lead acid batteries.

Some lithium batteries also do not have temperature sensors and I think it will damage the battery if you try to charge it when it is too cold.

 

[John Frum]

Some lithium batteries also do not have temperature sensors and I think it will damage the battery if you try to charge it when it is too cold.

Charging below at or below 0 celcius will definitely harm a lifepo4 battery.
@ScottRoz the temperature sensor on the dc2dc charger is for lead acid batteries to adjust the charge current down if the battery is hot.
Nothing to do with lifepo4 low temperature cutoff.

 

[Arbee]

I've been looking at this charger for our van build as well, so am following. I've also watched many of the Will Prowse videos and remember some cases where if the Lithium batteries have their own internal temperature sensors, the BMS will usually handle temperature range protection. This means that you don't need to (or perhaps should not) use the temperature sensor input on the charger.
It looks like you may be using that input. If your environment is within normal charging temperatures for the battery at minimum you could test by disconnecting that sensor in case it is not working correctly. That may explain why it seems to charge on SLA, but not Lithium. I think the temperature sensor only comes into play for Lithium, so likely the charger ignores it when set to SLA. If you have not watched, I would check out the Will Prowse review of that unit and perhaps the one where he opens up the Renogy battery to show how it works.

Scott, I like where your thinking is but I think it needs a bit of redirection towards how I believe the DCC50S (or 30S) operates.

According to page 9 of the product's manual there is no temperature compensation when setting the battery type of the product to the lithium battery setting.

https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf

So ironically, the temperature sensor, I reason, only comes into play when setting the product for non-Lithium type batteries, rather than vice versa as you stated.

Another interesting point, and maybe the one useful to the OP is that on page 17 of the manual it states:

"If the service battery type is set to lithium, the DCDC will stop charging the service battery when its temperature (I have to believe here the product, not the battery) is lower than 1℃, and recover to charge when it’s higher than 3℃."

Maybe the SLA battery type setting is working and the Lithium type is not because the OP is experiencing freezing temperatures(??).

I run this setup with a Relion LT 20 amp LiFePO4 battery. Aside from this battery having a BMS (battery monitoring system) that prevents it from accepting charge at freezing temperatures (which if not substantially reduced in power at such temperatures I understand can permanently damage of LiFEPO4 battery) the battery will use the charge current initially to heat the battery (the "LT" aspect of the product) if required, before using that current for battery charging.

Although nobody wants to throw more $ than they already have at their solar solution, if this explanation is the correct one, there may be a way of "having your cake and eating it too here," by acquiring Renogy's BT-2 (not BT-1!!!) bluetooth module. It plugs into the DCC50S (or 30) and allows you to select a battery type called "User" (not available from pressing the battery type button) from a IOS or Android phone app, where you can plug in the same charging parameters for your battery as are by default assigned by the DCC50S (or 30S) to a Lithium battery, but because it is configured as a "other" type battery, not a Lithium battery, may not be subject to charge current being deprived to the battery during the day, just because the ambient temperature is below freezing.

The battery type indicated button (1 or 4) on the extreme front right of the product turns white in color for "user selected" battery type.

 

[mikefitz]

Charging below at or below 0 celcius will definitely harm a lifepo4 battery.
@ScottRoz the temperature sensor on the dc2dc charger is for lead acid batteries to adjust the charge current down if the battery is hot.
Nothing to do with lifepo4 low temperature cutoff.

 

[mikefitz]

The charger will not function on the lithium setting unless the temperature sensor is fitted and connected.

Mike

 

[John Frum]

The charger will not function on the lithium setting unless the temperature sensor is fitted and connected.

Mike

Works without temperature sensor in this video.

 

[John Frum]

from the manual
"The proper battery charging voltage is important for optimum battery performance and longevity. This Remote Temperature Sensor measures temperature at the battery, allowing the DC-DC charger to use this data for accurate temperature compensation and charge voltage adjustment.NOTENo temperature compensation when charging lithium battery." -- https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf

Not sure why @mikefitz is getting different results.

 

[Arbee]

The charger will not function on the lithium setting unless the temperature sensor is fitted and connected.

Mike

I'm sorry Mike, I'm with @smoothJoey on this. Your above statement, I'm sure unintentionally, is pretty much the antithesis of product guidance. Simply put, the temperature sensor should not be fitted or connected if the owner sets the (house) battery type on the device to "Lithium."

https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf

I find this guidance on the top of page 9 where the manual discusses the Battery Temperature Sensor, at the end of this statement.

...a tiny detail easily missed: no doubt.

Some more color commentary: this "Lithium" type house battery setting will prevent the DCC50/30S from charging when temperatures are at or below freezing--despite what is likely a second line of defense in most LiFePO4 BMS' in not accepting charge at such temperatures. And clearly, for most situations, this is a good thing when dealing with LiFePO4 batteries.

But, as I run a Relion LT (low temperature) series LiFePO4 battery, which uses initial charge current to heat the battery, need be, before accepting that current for charging purposes, I deliberate went out and purchased Renogy's BT-2 product, that along with Renogy's smart phone BT app, allows the owner to custom set a (house) battery type of "User," along with customizing the various charging voltages--which I've made similar to the ones pre-programed for Lithium type house batteries.

I set the battery type to "User" precisely to get current to flow from the DCC50/30S at all temperatures, not only knowing the battery's BMS won't accept the charge if harmful to the battery, but more importantly, to allow this sub-freezing current to flow to the battery's heating components.

 

[Arbee]

I think that the Lithium charging will use a higher voltage than the setting for SLA, so it will be good to get that resolved. Otherwise you may not reach the full capacity of your batteries.

Hi Scott:

The last page of the product's manual https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf highlights the different voltages programmed into the device for each of its house battery type settings the owner may select.

The "User" setting shown is only configurable, along with the voltages the owner assigns to this custom house battery type, by purchasing the Renogy BT-2 product, and downloading to a smart phone (and using) the Renogy BT app.

 

[Arbee]

Sorry if this post is in the wrong place. Just installed a new DCC50s in my van. Currently have x2 Renogy LiFePo batteries, connection from my solar panels, and connection from the starter battery/alternator. The batteries aren't charging when I set the DCC50s to LI battery type, but seem to charge when I set it to SLA/Default. What am I doing wrong?

When you discovered this lack of charge, was the ambient temperature around the DCC50S at or around freezing? I ask because the product will not charge, when the house battery type is set to Lithium, if such cold temperatures are present.

 

[MisterSandals]

Simply put, the temperature sensor should not be fitted or connected if the owner sets the (house) battery type on the device to "Lithium."

When you discovered this lack of charge, was the ambient temperature around the DCC50S at or around freezing? I ask because the product will not charge, when the house battery type is set to Lithium, if such cold temperatures are present.

I am playing the home game and following along because i may be helping a friend with her DCC50.

I am wondering how the DCC50 could detect a freezing temperature if the temp sensor “should not be fitted or connected... Lithium”.

Are you implying the DCC50 has an internal sensor?

 

[Arbee]

I am playing the home game and following along because i may be helping a friend with her DCC50.

I am wondering how the DCC50 could detect a freezing temperature if the temp sensor “should not be fitted or connected... Lithium”.

Are you implying the DCC50 has an internal sensor?

Correct sir....and "implying" is the perfect word to describe my advice/sentiments.

Nothing I've found to date expressly confirms or denies the presence or absence of such an internal sensor. I'm forced to conclude its presence from the two remarks in the manual about how the external temperature sensor is contraindicated for house battery types of the "Lithium" setting variety, and how the DCC50/30S won't charge when ambient temperatures are at or around freezing when such a user selected "Lithium" battery type is chosen.

 

[Arbee]

I am playing the home game and following along because i may be helping a friend with her DCC50.

I am wondering how the DCC50 could detect a freezing temperature if the temp sensor “should not be fitted or connected... Lithium”.

Are you implying the DCC50 has an internal sensor?

I just sent this question to Renogy:

The manual for the above products (DCC50/30s) says that both the Battery Temperature Sensor is effectively ignored when the owner sets the house/service battery type to "Lithium" (page 9) and that under this battery type selection, the product, or at least the DCDC portion of it, will stop charging the the house/service battery 'at or near freezing temperatures' (page 17).

How does the DCC50/30S know the temperature without the sensor and exactly which of the two current inputs, solar, alternator or both are stopped under freezing temperatures? I'd think that "DCDC," as stated in the manual, implies the alternator's current only, if available, is blocked at freezing temperatures but please elaborate.

 

[MisterSandals]

Nothing I've found to date expressly confirms or denies the presence or absence of such an internal sensor.

I hope for the product’s sake that the charge controller temp is not used for the decision that should involve the battery’s temp.
I can see quite a few scenarios where the batteries could be located outside a temp controlled area while the charge controller is warm and cozy.
I have to believe an engineer would have known better...

EDIT: “i would like to believe”

 

[John Frum]

I just sent this question to Renogy:

The manual for the above products (DCC50/30s) says that both the Battery Temperature Sensor is effectively ignored when the owner sets the house/service battery type to "Lithium" (page 9) and that under this battery type selection, the product, or at least the DCDC portion of it, will stop charging the the house/service battery 'at or near freezing temperatures' (page 17).

How does the DCC50/30S know the temperature without the sensor and exactly which of the two current inputs, solar, alternator or both are stopped under freezing temperatures? I'd think that "DCDC," as stated in the manual, implies the alternator's current only, if available, is blocked at freezing temperatures but please elaborate.

Did you get a response from Renogy?

 

[Arbee]

Joey, sigh:

One does not get a written "answer" from Renogy so much as a recitation of that already in the owner's manual and that conscientious owners like you and I already read, and because of this wording, question Renogy on.

It's one big viscous cycle. I've called them on this. Their reply is that their sorry that can't be of more help.

That said, and to answer your question as well as justify my sentiments:

Thank you for contacting Renogy.

The DCDC will lower the output power when its internal temperature is in the range from 65℃ to 80℃. It will stop charging when the temperature is higher than 80℃, and recover to charge when the temperature is lower than 60℃.

If the service battery type is set to lead-acid, the DCDC will stop charging the service battery when its temperature is lower than -36℃, and recover to charge when it’s higher than -34℃

If the service battery type is set to lithium, the DCDC will stop charging the service battery when its temperature is lower than 1℃, and recover to charge when it’s higher than 3℃

No temperature compensation when charging a lithium battery.

We are basing all this information on the manual. Because that's the best recommendation we can give you.

Really: why is that the best recommendation you can give me? We can't you contact product engineers to determine exactly how the product works? Is that because since its initial implementation that so many things have been tweaked and Lord only knows which features ended up in the overseas build you got your hands on?

 

[Arbee]

Sorry if this post is in the wrong place. Just installed a new DCC50s in my van. Currently have x2 Renogy LiFePo batteries, connection from my solar panels, and connection from the starter battery/alternator. The batteries aren't charging when I set the DCC50s to LI battery type, but seem to charge when I set it to SLA/Default. What am I doing wrong?

As I review this thread and don't see this question addressed, is the location of your Renogy LiFePO4 batteries when were freezing or near freezing temperatures can happen?

Clearly, a decent LiFePO4 battery's BMS is going to reduce charging current near such temperatures to prevent damage to the battery: a fact that is independent of what battery type you set your Renogy DCC50S house battery at, but none the less, I was wondering about this.

 

[Grant S]

I am thinking of buying the DCC50S as a first time user and I came across this thread and the discussion of the temperature sensor's action with a lithium battery.

I read the manual and IMHO it is saying that:-

• you DO need to connect the temperature sensor to a lithium battery;
• the charger WILL use that sensor to turn off the charging when temp drops to 1C and turn it back on when it rises to 3C; and
• unlike the non-lithium batteries, the charger will NOT be shaping the voltage with a Temp. Compensation Coefficient of -3mV/°C/2V. It will simply apply the standard lithium charging program as soon as temp is over 3C. What the battery's BMS does with that voltage is up to the battery manufacturer.

I hope that clarifies the confusion.

And, as a newbie, can anyone help inform me if they see any special danger or battery harm from the above behaviour, when using a LiFePO4 battery?

cheers,
Grant