BCDC Battery Charger?

RyanAndLulu

I am a bit OCD about my battery dying as I rarely camp where there are hookups. I have an early model T@B 400 (2018) with the AGM battery and factory installed solar panels which lasts ~3 days in cloudy weather. I also recently moved my trailer to a storage facility instead of parking at my house which means I no longer have a power source to charge the battery before or after a trip (besides a noisy/smelly generator). Has anyone installed a Redarc battery charger? Wondering if this will prolong my battery usage. Thanks!

p.s. I am a software engineer, not an electrical engineer... I am pretty klueless on anything electrical!

https://www.etrailer.com/dept-pg-Battery_Chargers-sf-Battery_Charger-sz-Vehicle_Battery_to_Auxiliary_Battery-pm-Redarc.aspx?utm_source=iContact&utm_medium=email&utm_campaign=etrailer&utm_content=190408-T-RV-SR-V-BCDC-ManufSP-B

Sharon_is_SAM

Does your solar not charge your battery while camping?

MuttonChops

Not sure why you want this additional charger.  With factory installed solar panels you already have a solar-2-battery charger.  You should also have (or can add) a TV +12V Battery line to your 7-pin which will also charge the T@B battery while driving.

Is your "storage unit" indoors or outside?  I store my T@B outside and have a small solar panel that does a great job keeping the battery topped off between travel adventure.

jkjenn

RyanAndLulu said:

I am a bit OCD about my battery running low as I rarely camp where there are hookups. I have an early model T@B 400 (2018) with the AGM battery and factory installed solar panels. I also recently moved my trailer to a storage facility instead of parking at my house which means I no longer have a power source to charge the battery (besides a noisy/smelly generator). Has anyone installed a Redarc battery charger? 

Ah, so you got the email from eTrailer, too?

I thought this looked like a very interesting solution. 
The benefits, as I read them were:
Faster charging 
Outsmart alternators
Charge from solar and the alternator, with the built in MPPT charger
Can charge luthium.

RyanAndLulu

@jkjenn
Ha!!! Yes!!! I was hoping someone in this forum was smarter than me and could explain what it 'really' does!

RyanAndLulu

Sharon_is_SAM said:

Does your solar not charge your battery while camping?

It does when I am parked directly in the sun... up here in the Pacific Northwest... that doesn't happen all that often :( I was camping in Oregon for 8 days last November and was fortunate enough to use a generator mid trip to charge the battery, but it was pretty low for most of the trip which didn't include using the Alde heat.

RyanAndLulu

MuttonChops said:

Not sure why you want this additional charger.  With factory installed solar panels you already have a solar-2-battery charger.  You should also have (or can add) a TV +12V Battery line to your 7-pin which will also charge the T@B battery while driving.

Is your "storage unit" indoors or outside?  I store my T@B outside and have a small solar panel that does a great job keeping the battery topped off between travel adventure.

Thanks for the input!! I store my trailer outside also which fortunately the solar does keep it topped off... but I live in the Pacific Northwest where it rains half of the year and it doesn't get the full charge that I am looking for. 

Sharon_is_SAM

Understood.  So, if you deplete your battery the night before you break camp, you don’t get a full charge before you need to store it.  

MuttonChops

RyanAndLulu said:

Thanks for the input!! I store my trailer outside also which fortunately the solar does keep it topped off... but I live in the Pacific Northwest where it rains half of the year and it doesn't get the full charge that I am looking for. 

I'm on the Bothell/Kirkland boundary line.

Lucky for me my storage spot (panel) has a South West exposure.

Sharon_is_SAM

I wonder how this compares to simply using a smaller gauge wire for the charge line and 7 pin ground?  How high of a current would 8 gauge allow? 

RyanAndLulu

Sharon_is_SAM said:

I wonder how this compares to simply using a smaller gauge wire for the charge line and 7 pin ground?  How high of a current would 8 gauge allow? 

You are no longer speaking my language #me-no-speak-electrical-talk

jkjenn

Sharon_is_SAM said:

I wonder how this compares to simply using a smaller gauge wire for the charge line and 7 pin ground?  How high of a current would 8 gauge allow? 

Essentially, the thicker the wire (smaller gauge) from your alternator to the plug on your TV that the trailer plugs into, the less juice that is lost. Increasing the thickness if your power wire used to be the easiest way to improve power output to the trailer.

It will depend on your TV. The gauge of wire won't make a difference of you have a smart alternator, which is becoming more common to reduce emissions.

Sharon_is_SAM

@jkjenn, how is this device not married to the same alternator output?

jkjenn

Sharon_is_SAM said:

@jkjenn, how is this device not married to the same alternator output?

This explains it better than I could:

https://youtu.be/ITamN84IiAo

N7SHG_Ham

I see how that works, something else to buy! You get the correct voltage out for battery profile selected despite fluctuating and/or low voltage dribbling out end of wire from the charge line. Didn't know these existed for campers, but commonly used in the ham radio world.

pthomas745

I was camping in Oregon for 8 days last November and was fortunate enough to use a generator mid trip to charge the battery, but it was pretty low for most of the trip which didn't include using the Alde heat.

The Alde hardly uses any power on propane.  Also, "pretty low for most of the trip" is sort of vague.  How are you monitoring  your battery?  Can you give us specific numbers on "pretty low?"  If you were trying to get a reading on your battery and the battery wasn't "at rest", then it will always read "low".

Sharon_is_SAM

Is this the same thing offered by Renogy?  DC to DC charger
Is this the answer to folks running their 3 way frig on battery while towing?

jkjenn

Sharon_is_SAM said:

Is this the same thing offered by Renogy?  DC to DC charger
Is this the answer to folks running their 3 way frig on battery while towing?

It is similar. Does not appear to give you an option to use solar, but it is also much cheaper. It might be a good solution!

Cbusguy

Not sure why you would want to use it for solar.   It is intended to isolate and manage a second battery from the primary.   This allows it to be of a different type from the primary, example lead acid tow vehicle starting battery, lithium trailer battery.

Your solar charge controller should be able to manage your trailer batterys.   

ScottG

Those are pretty slick. In simplest terms they seem like the reverse of an MPPT solar controller--where the MPPT controller can step down extra voltage to increase charge current from your panel, this device can use extra current to step up the charging voltage from your vehicle.

Not sure I need it enough to justify the cost, but still slick.  :-)

ScottG

In fact, upon closer inspection, it appears this is an MPPT solar controller as well.

jkjenn

Cbusguy said:

Not sure why you would want to use it for solar.   It is intended to isolate and manage a second battery from the primary.   This allows it to be of a different type from the primary, example lead acid tow vehicle starting battery, lithium trailer battery.

Your solar charge controller should be able to manage your trailer batterys.   

If you have solar mounted on your TV will the BCDC will draw from your solar before your TV (assuming in transit.) It would save extra where and tear on your TV battery and as also keep th in gs go il ng when parked but still connected to your TV. I am hoping my factory solar will help, but this is also a possible solution.

ChanW

Ok, I'm confused re simultaneously tow-vehicle charging the Tab battery while the roof top solar is connected.

How does the Victron MPPT controller behave when there's a second source of charge being applied to the battery? For example, if connected to the seven pin of the TV while simultaneously connected to your solar system? 

Isn't the TV alternator's charge rate going to confuse the controller as to what stage it's in?

jkjenn said:

If you have solar mounted on your TV will the BCDC will draw from your solar before your TV (assuming in transit.) It would save extra where and tear on your TV battery and as also keep th in gs go il ng when parked but still connected to your TV. I am hoping my factory solar will help, but this is also a possible solution.

jkjenn

ChanW said:

Ok, I'm confused re simultaneously tow-vehicle charging the Tab battery while the roof top solar is connected.

How does the Victron MPPT controller behave when there's a second source of charge being applied to the battery? For example, if connected to the seven pin of the TV while simultaneously connected to your solar system? 

Isn't the TV alternator's charge rate going to confuse the controller as to what stage it's in?

jkjenn said:

If you have solar mounted on your TV will the BCDC will draw from your solar before your TV (assuming in transit.) It would save extra where and tear on your TV battery and as also keep th in gs go il ng when parked but still connected to your TV. I am hoping my factory solar will help, but this is also a possible solution.

It's a good question and I don't know, yet. The MPPPT reacts to the voltage, so theoretically, the MPPT would see the battery voltage and only send what is needed to reach optimal charge.

Cbusguy

The solar controller only really cares about voltage.   So charging from first is what ever is the highest voltage.

I imagine the new box would be the same way.  As long as the source battery alternator combo has a higher voltage than the second battery or the voltage set point it will charge it.

With out testing I imagine both boxes will charge the battery till it hits their various charge points bulk float and absorption


The biggest job of this box is isolating the tow vehicle battery from the trailer battery.    

Cbusguy

@N7SHG_Ham. They are very common on fire trucks and squads.     It wouldn't do not being able to start your truck after leaving your lights flashing during the call

N7SHG_Ham

@Cbusguy isolators yes, this is way more than that and while it does isolate the trailer battery, the more interesting thing is being able to get a higher voltage for proper battery charging despite lines losses from the TV.

As far as emergency vehicles, I have never seen anyone shut vehicle off while on a call, but I get the importance of an isolation device. I have LED strobes on my work truck and can leave those on for hours with no issue, I think today with almost all emergency response vehicles using LED it is less of an issue.

Cbusguy

@N7SHG_Ham the principle is like an isolator with mppt controller.     The million dollar question is it addressing a problem that doesn't exist?

I would like an isolator, the renogy is close enough to that price I am sure it is possible.  The other thing to keep in mind is renogy is just a remarketer.    I am hoping the same thing happens that has happened with the solar controllers.  Rich solar introduced a solar controller identical to the renogy for 40 percent less.   We will see

N7SHG_Ham

I think it does address the issue of poor charging from the TV. I have a separate MPPT solar controller so not as interested in that unless it solves some issue of using a separate controller in conjunction with the unit. Being able to provide proper charging to the trailer battery is key and I think this unit will help in that regard. Am I buying one tomorrow? No, but I am going to learn more about this device and what benefit it brings. I know from past experience with older trailers with flooded batteries that the TV charging always seemed problematic and it may/may not be a concern with new 400 with solar on roof which may help to overcome those issues.

ChanW

Here's an interesting and pretty complete discussion on multiple-source charging and how a solar controller might behave. Not sure that it can help us with our simple Tab converter and our basic TV alternator, but our Victron controller is smart enough, and maybe has enough options to vary, with some trial and error and research.

https://roadslesstraveled.us/charging-rv-marine-batteries-solar-power-shore-power/

jkjenn said:

ChanW said:

Ok, I'm confused re simultaneously tow-vehicle charging the Tab battery while the roof top solar is connected.

How does the Victron MPPT controller behave when there's a second source of charge being applied to the battery? For example, if connected to the seven pin of the TV while simultaneously connected to your solar system? 

Isn't the TV alternator's charge rate going to confuse the controller as to what stage it's in?

It's a good question and I don't know, yet. The MPPPT reacts to the voltage, so theoretically, the MPPT would see the battery voltage and only send what is needed to reach optimal charge.