Renogy DC to DC MPPT Charger Install

I'm trying to locate the ING (D+) signal wire from the (smart) Alt. on my 2015 Tacoma 2x4 Access Cab. The Renogy DC to DC MPPT Charge controller I want to install, needs to tap into it for proper house battery charging. Thanks for any technical help.

 

Did you ever get the charger installed?

 

No, I have not purchased the unit yet. But I did find the D+ wire and why it is necessary for a modern Alt. install.

 

What did you find out? I was under the impression that the Tacomas "smart" alternators weren't technically considered smart

 

If the Alt. output voltage drops to low, around 12.5 volts, the Renogy unit will stop charging the "house" battery. That seems to happen regularly on newer alts., so you need the signal wire attached to the D+ wire of the alt. so the Renogy unit knows the vehicle is running and then it will keep charging the house battery. Or so I believe. Its hard to get answers out of Renogy about this from there web site.

 

From my research you take that signal wire and attach it to any 12v source that is turned on by the ignition. From what I have seen that source is usually the fuse that is for the ignition. My thought process is to use a fuse jumper and link it to the 15a ignition fuse (if that makes sense). From what I can gather, this will tell the dc-dc charger to turn on as soon as the ignition is turned on and leave it on until it is turned off. I may run a switch in that ignition wire so that #1. I can turn it off when I dont have my fridge or anything like that in the truck. #2. I dont think i want that dc-dc charger turned on as soon as the ignition is turned on ALL THE TIME. What i mean is, what if i just want to blast some tunes at camp? I dont want that charger on, I want the batterys isolated. Also if its super cold out or something like that, I dont think i want that charger to start charging until the motor and alternator are warmed up. just a simple CH4x4 switch would do the trick, i believe.

I am in no way shape of form a 12v expert or even anything close. But i think that will work. Ill except any lashings hahahaha

 

I should aslo say, i have only been researching dual battery systems since i got my truck fridge (3 days ago). I am going to but one soon. The redarc is what i want, but i dont want to dump $381 at this moment. I have a 5-6 day trip coming up and i want to be able to run my fridge without any issues. We will be doing a lot of driving during the days and camping from around 4pm till 8 or 9 am.
Im a little list on the amps part, as in do i want the 20 40 or 60 amp unit. I think the 40 amp is what i want to go with.
Any input is appreciated!!

 

I used the CTEK DC charger. It’s not water-proof but I talking under the passenger seat has worked out.

https://www.tacomaworld.com/threads/2nd-gen-dual-battery-with-on-board-charger.636037/

 

Im in the middle of hooking up the 20A version of charger. For the time being I have the D+ on a switch. What are you guys thoughts of connecting it to the inverter switch as the power on/off?

 

Anyone find a good solution for where to connect the IGN d+ signal wire? I've ordered the 30A MPPT DCDC charger from Renogy, but am still digging around through forums to find a way to connect that wire.

 

Has anyone found a solution for this and/or can share a wiring diagram?

 

I installed the DCDC charger w/ MPPT and right off the bat found that it would charge whether the ignition wire was connected or not. I got the BT2 module (not super useful, but that's another thread) which does give me a volt reading at the charger while the engine is in, and it seems to stick around the 14+ V range, which, per Renogys guides (Google around for some of their suggestions on how to diagnose traditional vs smart- the DCDC manual doesn't really go into that subject) suggests that Tacoma's have a traditional alternators. I have a 2020 SR- not sure if there is a difference in alternators in other models. So, since I already ran the wire, I do have the ignition wire connected to the 10A A/C fuse in the engine bay (hot when engine is on, not when engine is off, doesn't seem to activate the charger when the mysterious emissions pumps kick on at night), but I don't think it's necessary for the charger to function. I've been using it daily for over two months now and it all seems to work as intended.

 

Thanks for the reply! What kind of second battery are you using, and are you finding that the MPPT charger in this unit is adequate from your solar panels? I'm not sure what your solar panel setup is like but i'm concerned about the low voltage max (25A). I'm running a Lithium battery at 100ah w/ 2 100W panels but i'm running them further away from the truck and concerned about adequate power transfer.

 

I haven't added any solar panels yet- I've just been relying on the alternator to charge periodically, which has been working for my fridge and lights set up thus far (at least during the cooler months). I have a single 125Ah AGM battery

 

Here's a rough video showing a bit of my install: https://youtu.be/SVAedNREYRk

 

Hey KJR. IIRC there is a grommet hole that goes in from the back of the cab by the bed. I think it would be prudent to run your wiring into the cab from there instead of the door jam.

I am planning on getting the same MPPT charger, thanks for showing us your layout. It looks like I will be setting mine up in the bed of the truck too now. I was hoping to put it under the hood but after reading the instruction manual it looks like it should be a little more protected from heat and dust.

I am sure I will have a few more questions in the near future. Cheers!
-M

 

PilotMM, thanks for the tip. If you happen to do any wiring into the cab through that grommet, I would be interested in seeing some pics. I agree, the charger isn't really weatherized, so the engine bay may not be the best location for it. I think the manual says that it can be mounted there, but then immediately goes on to say that it must be in a location free from water, dust, excessive heat, etc.

 

Over a year later... I'm installing a Renogy DC-DC 40A charger in a 2007 Taco and I had the same question as OP. The DC-DC charger/ isolater has the same D+ wire as the MPPT charge controller with DC-DC function. I originally looked at this thread before I stuck my head under the hood. Looks like Kjr241 got it to work connected to the 10 amp A/C fuse and that's awesome. I've just spent some time under the hood checking fuses/ circuits with a multimeter and I found that the 10 amp A/C only puts out 12V when the A/C is turned on.

The D+ signal wire should be connected to a circuit that puts out roughly 12V after the vehicle is running -- and not before the vehicle has been started or after it has been turned off. There are a bunch of circuits that actively output 12V when the key is turned to "ACC" or "On" before the engine is started. To avoid potentially killing your battery if the key is left in the ACC or On/Run position (with the engine turned off), these should be avoided.

Reference the photo below. This picture was taken from the driver's side of the vehicle, looking down on the large fuse box in the engine compartment. I've marked a gray wire that I tested with my voltmeter, and it outputs the required voltage only after the vehicle has been started, and it discontinues voltage output when the vehicle is turned off. This is the wire I'm going to splice into for connecting the D+ signal wire. I'll let you know how it goes (waiting on parts).

I had previously installed a voltage sensitive regulator (battery isolater) on this vehicle and I had been using it to charge a 100Ah AGM battery before purchasing the Renogy DC-DC charger. The VSR worked okay but it wasn't providing the ideal charge conditions (voltage and current) for the AGM battery, which resulted in the battery failing prematurely. The Renogy DC-DC charger can be used to control the absorption and float charge voltages as well as the charge current going to the auxiliary battery. In my case, the D+ signal wire can also be connected to the auxiliary battery side of the VSR since it also outputs the required voltage only while the vehicle is running and is isolated from the cranking battery after the vehicle is turned off. If I do this, the VSR will no longer be connected to the auxiliary battery, it will only be used to connect the D+ signal wire and the auxiliary battery will only be charged with the newly-installed Renogy DC-DC charger input side connected directly to the cranking battery.

 

i never cared fir the Renogy products, interface wasn’t intuitive.

Check out the VictronConnect mppt charge controllers. Many have built in Bluetooth connectivity that works with iPhone and android. I’ve installed several units in boats, sprinters and my own trucks. Good stuff.