Renogy DC DC Charger w/ MPPT

Can you use this with a Nissan NV 2500 cargo van that has a 120 amp battery in it?

It seems like running a 400W 12v system with the DCC50S is fairly trivial using Will's awesome diagram/being within the MC-4 amp cutoff, but can anyone provide a little detail on how one could 'max out' the DCC50S with say 660W of panels? Do you run 24 max voc panels? 12v parallel with a combiner box? Looking to do a skoolie rooftop build with this controller, but it seems extra tricky with that annoying 25V max cutoff.....

Newbee here. I have a 2019 sprinter which I have install 3 Renogy solar panels on running trough my DCC50s. My sprinter came with the additional AGM AUX batter under the passengers that I would like to be able to use with my setup which is currently running off of an Renogy 100ah lithium. So my questions are.

Can I charge both off of solar some how?
Could I use both some how? I'm not sure I should mix them, but maybe there is a safe way to do it.

Thanks

First off, thank you to everybody on this thread. I bought the DCS 50A because of you guys as it fits my needs. So far the install has been fine except I don't know where on the alternator the IGN wire is supposed to attach. Where my one finger is or where my teeth fingers are. Any help?

*two fingers

Oops, forgot the pics

@WillyG Hey, were you able to get your ignition wire setup? I think Renogy doesn't supply much info around that because it would take a massive book to cover all that info, plus the liability...

Basically, you're looking for the ignition wire for your vehicle, typically found under the driver dash, in the driver kick, or at the steering column. If you've ever installed a car alarm, you know what I'm talking about. Best option for you is to hit up your local car stereo shop that has a Direct Tech account with Directed where they can print out the wire locations/colors for your exact vehicle. I have a 2013 Highlander, it was a PITA to get to it, but its actually on the fuse box under the driver dash on the back side of it.

To test, you'll want a test light (preferably a multimeter). The wire should read 0 volts when the ignition is off and around 12-12.5 volts when the ignition is on ( to the position that you'd be in when the car is running, not just accessory).

Way easier that trying to find the wire at the alternator, which is may not be anyway.

I've got the DCC50 + the BT2.

DCC50 has been good so far, but I totally drained my battleborn and drove 4 hours already and its still not charged back up... Need to look into it.

The BT2 is finicky, but once working, has stayed working. The renogy app is pretty garbage. Renogy still hasn't responded to my questions from like 6 weeks ago... Luckily I found the info I needed from you wonderful people to get it started in Aug.

I'll post some pics of the build as soon as I figure out where I'm supposed to in the forum lol...

Happy Thursday!

BagheeraTheLion said:

Best option for you is to hit up your local car stereo shop that has a Direct Tech account with Directed where they can print out the wire locations/colors for your exact vehicle.

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I'm like to diy, but I would gladly pay $100.00USD for someone else to run that cable.
Excellent idea.
I do want to know where it terminates though just in case I have to replace a fuse.

@smoothJoey I agree, if you're not familiar with ignition systems/vehicle electronics paying a legit shop or person to do it might be best. And yea, I put a fuse on there as well, just in case. 3 amp I think. Also, I trimmed the insolation of the wire back a bit and soldered it, did not cut the vehicle wire.

BagheeraTheLion said:

@smoothJoey I agree, if you're not familiar with ignition systems/vehicle electronics paying a legit shop or person to do it might be best. And yea, I put a fuse on there as well, just in case. 3 amp I think. Also, I trimmed the insolation of the wire back a bit and soldered it, did not cut the vehicle wire.

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I can read a wiring diagram but I'm too old for the crawling around holding a penlight in my teeth.
If I was going to do that it would have to be a much bigger prize.

@smoothJoey hahaha.. I hear you. I'm def not in my 20's anymore (when I was working at a shop) but this time round reminded me of one of the reasons I don't do it anymore regularly. The bigger prize for me in this situation was having my rig up and running. Not sure I'd want to do this on someone else's car at this point lol

smoothJoey said:

I can read a wiring diagram but I'm too old for the crawling around holding a penlight in my teeth.
If I was going to do that it would have to be a much bigger prize.

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Same, but I have to add "too fat" for myself.

toverb said:

I really want to use this charger for my LFP bank keeping lead acid for the starter battery to secure the alternator. But I don't want to charge the LFP batteries to more than 13.8 V and stop charging when they reach that level. I don't want any float charging for the LFP's.
Can I do that with this charger?

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Hey sir, did you ever get an answer to this? I have (2) 100ah Renogy batteries connected to this DCC50s with (4) 100W solar panels. Wondering if you were able to get an answer from Renogy on this? Did you end up getting this to work out?

hi guys looking for advice on connecting dcdc50.
I am looking to install this to my ford transit van which has factory fitted dual 95 amp batteries under drivers seat { uk version } known as starter battery and aux battery. there is a battery isolator which cuts out all power if aux battery voltage drops conserving starter battery drain. all is working fine as this has tripped a few times if I have left van doors open with interior lights on and engine switched off. I just press reset switch to get electrics back on again. I wish to connect dcdc50 with two 110 amp leisure batteries for camper conversion.
which battery should i take the live input from.
Thanks in advance.
dave.

I'm a little nervous about warnings that I could overheat my conventional alternator (Ford E450, 155 amps) in trying to charge my LiFePO4 400ah battery. I have the 50 amp Renogy unit, btw. Other than installing an inline, battery-type on/off switch on the battery cable before the Renogy DC-DC unit (to manually allow me to give the alternator an occasional break), does anyone know of a way of installing a remote switch using small wire somehow in conjunction with the ignition-sensing port, etc.? I've seen that on YouTube for the 20 amp unit (RV with Tito). BTW, I do not yet have PV panels installed, so the battery will be getting the full 50 amps from the alternator. Thanks!!

Will Prowse said:

Compact with a sturdy design, it was built tough for all conditions.

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That part i find confusing.
The manual states it will not tolerate dust,heat or even splashed water.
They then go on to advise you to mount it under the hood or on the chassis rail where it is likly to encounter all three.

mainebluedave said:

hi guys looking for advice on connecting dcdc50.
I am looking to install this to my ford transit van which has factory fitted dual 95 amp batteries under drivers seat { uk version } known as starter battery and aux battery. there is a battery isolator which cuts out all power if aux battery voltage drops conserving starter battery drain. all is working fine as this has tripped a few times if I have left van doors open with interior lights on and engine switched off. I just press reset switch to get electrics back on again. I wish to connect dcdc50 with two 110 amp leisure batteries for camper conversion.
which battery should i take the live input from.
Thanks in advance.
dave.

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will go for the trial and error approach....

mainebluedave said:

will go for the trial and error approach....

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I would connect to the starter battery.

The DC to DC charger provides the battery isolation function, and should be connected to the starter batteries.

I would get rid of the battery isolator and connect the Aux battery in parallel to the starter battery (assuming they are the same battery). If they are different battery types/specs then I would replace the aux battery with a duplicate of the starter battery. This will reduce the likely hood of having a dead starter battery.

When I bought my Ford E350 diesel I was surprised to find the starter batteries were 6 years old. Typical battery life here in Phoenix AZ is 2 to 3 years due to the brutal summer heat. Part of this is probably due to their location (not in the engine compartment), but part is also due to having 2 starter batteries. It takes a lot of current to start a diesel so double batteries is the way to go.

Has anyone tried using a larger solar panel around 38-41 Open Circuit Voltage with the DCC50?

I'm looking at some ~350W ones which are way over voltage for the 25V max specified but wondering if I could put a cheap mttp in between to lower it to 24V. Would that work and would it be worth it? The reason wouldn't just connect that other mttp to the batteries is that they are lithiums so I need the low temp shutoff that the DCC50 provides. I may also just get the Victron 100/30 which has that but is a lot of extra money for a very small difference, or just accept the limitation and get a 200W panel.

Unfortunately I only really have space on my van roof for a single panel and this can be a big 350W one or a 200W one.. Weirdly the 350W ones are way cheaper so you see my dilemma!

Also was considering putting either manual shutoffs or some kind of relay system to switch between solar and alternator inputs so I can get full 50a from the solar when not driving, but guessing the 25V limit would still apply?

This is my first build so pretty noob!

I've been using my Renogy DCDC MPPT 50A controller successfully in my rig setup for six months now with 4x 100ah LiPo4 batteries and a lead acid starter battery with 400watts of solar.

I recently upgraded to an electric water heater and wanted to experiment what would happen if I drained my lithium batteries to ensure my starter battery was actually isolated so I wouldn't be stranded anywhere.... Two days later lithium batteries drain to 12.5v and I go to start my rig to charge with alternator and the starter battery is dead! (11 volts!)

How is this possible with battery isolating I asked?

I've double checked all my wiring, and ensured it is hooked up correctly (six months no problem).

Called Renogy and they said if you drain your lithium batteries far enough your starter battery will try and charge your Lithium batteries WHAT??!? This completely negates the entire purpose of having battery isolation in my opinion!

I've run this experiment several more times with the same result; when my lithium batteries drop below 12.6 my starter battery is completely dead.

This doesn't seem right, can I install another isolator between my starter battery and the DCDC MPPT controller in order to avoid this unnecessary draining? Hopefully the starter battery still gets a top off from solar when voltage is over 13.2.

Has anyone else had this issue?

bodiepetro said:

I've been using my Renogy DCDC MPPT 50A controller successfully in my rig setup for six months now with 4x 100ah LiPo4 batteries and a lead acid starter battery with 400watts of solar.

I recently upgraded to an electric water heater and wanted to experiment what would happen if I drained my lithium batteries to ensure my starter battery was actually isolated so I wouldn't be stranded anywhere.... Two days later lithium batteries drain to 12.5v and I go to start my rig to charge with alternator and the starter battery is dead! (11 volts!)

How is this possible with battery isolating I asked?

I've double checked all my wiring, and ensured it is hooked up correctly (six months no problem).

Called Renogy and they said if you drain your lithium batteries far enough your starter battery will try and charge your Lithium batteries WHAT??!? This completely negates the entire purpose of having battery isolation in my opinion!

I've run this experiment several more times with the same result; when my lithium batteries drop below 12.6 my starter battery is completely dead.

This doesn't seem right, can I install another isolator between my starter battery and the DCDC MPPT controller in order to avoid this unnecessary draining? Hopefully the starter battery still gets a top off from solar when voltage is over 13.2.

Has anyone else had this issue?

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unfortunately your story confirms that I'm not that strange as I never rely on the insulation capabilities - especially as the manual states that the DCDC "will charge the starter battery if there is surplus solar power". Good old VSR or Ignition relay is what I use...

BTW well done to get a response out of Renogy Customer Service!

samb said:

Has anyone tried using a larger solar panel around 38-41 Open Circuit Voltage with the DCC50?

I'm looking at some ~350W ones which are way over voltage for the 25V max specified but wondering if I could put a cheap mttp in between to lower it to 24V. Would that work and would it be worth it? The reason wouldn't just connect that other mttp to the batteries is that they are lithiums so I need the low temp shutoff that the DCC50 provides. I may also just get the Victron 100/30 which has that but is a lot of extra money for a very small difference, or just accept the limitation and get a 200W panel.

Unfortunately I only really have space on my van roof for a single panel and this can be a big 350W one or a 200W one.. Weirdly the 350W ones are way cheaper so you see my dilemma!

Also was considering putting either manual shutoffs or some kind of relay system to switch between solar and alternator inputs so I can get full 50a from the solar when not driving, but guessing the 25V limit would still apply?

This is my first build so pretty noob!

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You won't see 50A from a 350w panel, also if you aren't driving then why would you need to shut off the alternator inputs?

Reed Cole said:

You won't see 50A from a 350w panel, also if you aren't driving then why would you need to shut off the alternator inputs?

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Ah very good point on not needing to shut off the alternator input! Yea I'd be expecting ~30a max from the solar I guess. Starting to think I may just use it as a 50a b2b and hook up a separate mttp.

samb said:

Ah very good point on not needing to shut off the alternator input! Yea I'd be expecting ~30a max from the solar I guess. Starting to think I may just use it as a 50a b2b and hook up a separate mttp.

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It's probably worth it to be able to use a 350w panel.