Renogy DC/DC install

[RJ Howell]

Having a bit of a time getting it to run.. I bought the 20a unit and ran the wiring yesterday from the battery and the 12v sensor to the tail lights for a 12v signal. No joy.. I do have 12V power in the line to the unit (tested).

Today I figured I'd run that sensor wire to the Battery + and ensure it has a signal of 12v power... No Joy... Power on that line, tested.

I'm setting up for Lithium so S1 off, S2, S3, S4 on and S5 off. That should be a 14.4v constant. From the manual, off is towards the printed numbers and on is away from. The manual is not shall we say, user friendly... It's a bit confusing.

I will call service tomorrow and work through this, yet if you know, please talk to me..

What is the proper DIP positions for Lithium? Which way is really on? Suggestions on what I've missed in wiring this thing???

I was not expecting this to be an issue...

[featherliteCT1]

This guy also has Lithium batteries and the Renogy DC to DC Charger.

Go to about time stamp 2:20 for dip switch photo.

Maybe this will help. Hope so!


https://www.youtube.com/watch?v=ww_4yhQPGwY

[bdosborn]

I ran into the same problem; the Renogy manual is garbage, support sucks (visit our forum!) and it seemed like there was a different setting for LiFePO4 at every website I visited. This is my current settings, I hope its right. This is the first and last Renogy product I buy.



Victron just came out with a smart DC-DC charger, I'm kinda hoping the Renogy craps soon out so I can put a better charger in.

Bruce

P.S. I used my driving lights to turn on the charger. PV charges during the day and the Renogy charges at night.

[John61CT]

Do not let it run while there is no charge source active.

Full user-custom adjustability of the charge profile is IMO a must-have in caring for LFP.

13.8 - 14V depending on C-rate, and a BMS that lets you adjust the balancing parameters.

[RJ Howell]

I ran into the same problem; the Renogy manual is garbage, support sucks (visit our forum!) and it seemed like there was a different setting for LiFePO4 at every website I visited. This is my current settings, I hope its right. This is the first and last Renogy product I buy.



Victron just came out with a smart DC-DC charger, I'm kinda hoping the Renogy craps soon out so I can put a better charger in.

Bruce

P.S. I used my driving lights to turn on the charger. PV charges during the day and the Renogy charges at night.

My DIP's are in the same positions as yours. That should be the 14.4 constant (best I can figure). Does your green light come on when it's running? I've yet to see a light, red or green.. I was wired to my running lights as well to engage the charger, then went direct to the battery to just prove it works.. Nada.. I think there's a issue with the unit.

[troubleScottie]

Having a bit of a time getting it to run.. I bought the 20a unit and ran the wiring yesterday from the battery and the 12v sensor to the tail lights for a 12v signal. No joy.. I do have 12V power in the line to the unit (tested).

Today I figured I'd run that sensor wire to the Battery + and ensure it has a signal of 12v power... No Joy... Power on that line, tested.

Not sure how you are wiring the device. You state "the battery". I am assuming there are 2 batteries -- the towing vehicle(TV) and the trailer (TD).

The typical trailer light wiring is not designed to deliver a 20A current flow. This would include the running lights and the positive DC wire of a 7 pin connector.

Optimally you are running separate wire (8awg or 6 awg) from the TV battery thru a fuse/breaker thru an isolation switch to the rear of the tow vehicle. Plus running a separate ground wire of similar gauge. This wire and a ground would have its own (Anderson ?) connector. These two wire (with similar gauge) would be routed from the connector across the trailer to the DC-to-DC device as input. The 12V sensor wire would also be connected to this 12V positive wire.

Have you checked that the ground does connect back to the TV battery?

Have you attempted to confirm that Renogy device to a spare battery (as the DC source) to confirm it is no dead on arrival (DOA) -- light go on, etc I am not sure if this is kosher eg the charging battery and battery to be charger might have to present for confirming.

[bdosborn]

Just checked mine, I have a relay in the trailer to turn on the running lights from the trailer battery. No green light when power is on the control terminals and the truck is *not* connected. I know mine works as I've measured the current flow with the Victron Battery Monitor when the truck was connected and running. I've never checked the green light when it was connected to the truck. I seem to remember that it didn't wake up till it was connected to the truck and power was available on the input and the control terminals.

Bruce

[RJ Howell]

Just checked mine, I have a relay in the trailer to turn on the running lights from the trailer battery. No green light when power is on the control terminals and the truck is *not* connected. I know mine works as I've measured the current flow with the Victron Battery Monitor when the truck was connected and running. I've never checked the green light when it was connected to the truck. I seem to remember that it didn't wake up till it was connected to the truck and power was available on the input and the control terminals.

Bruce

Hmm.. Sounds like how it's supposed to work. All connected, supply running, draw required (battery below startup). Green light is supposed to be on. Now writing that, I'm curious about what the startup voltage needs to be at? Or does it? Constant 14.4 says to me, it's on when below 14.4... Hmm...

[tony.latham]

support sucks (visit our forum!)

Sheeeesh.

Tony

[RJ Howell]

Having a bit of a time getting it to run.. I bought the 20a unit and ran the wiring yesterday from the battery and the 12v sensor to the tail lights for a 12v signal. No joy.. I do have 12V power in the line to the unit (tested).

Today I figured I'd run that sensor wire to the Battery + and ensure it has a signal of 12v power... No Joy... Power on that line, tested.

Not sure how you are wiring the device. You state "the battery". I am assuming there are 2 batteries -- the towing vehicle(TV) and the trailer (TD).

The typical trailer light wiring is not designed to deliver a 20A current flow. This would include the running lights and the positive DC wire of a 7 pin connector.

Optimally you are running separate wire (8awg or 6 awg) from the TV battery thru a fuse/breaker thru an isolation switch to the rear of the tow vehicle. Plus running a separate ground wire of similar gauge. This wire and a ground would have its own (Anderson ?) connector. These two wire (with similar gauge) would be routed from the connector across the trailer to the DC-to-DC device as input. The 12V sensor wire would also be connected to this 12V positive wire.

Have you checked that the ground does connect back to the TV battery?

Have you attempted to confirm that Renogy device to a spare battery (as the DC source) to confirm it is no dead on arrival (DOA) -- light go on, etc I am not sure if this is kosher eg the charging battery and battery to be charger might have to present for confirming.

Let's see if I can clarify. Wired from truck battery +/- to the device input (thru a working fuse). Wire tested with Meter. Signal wire is back on the running lights (ignition), but did run the signal wire back to the battery positive (truck) as a test. Output is on my LiFePo battery run down to 13.16 as I run my refrigerator off it. I am metering only on the output side right now, so only if the voltage increases on the battery will I know if the unit is working. The green light is supposed to come on is running (doesn't) and red light if a fault (nope).

Difference for me is that I'm running to the truck camper, not a trailer. Same principles in play though..

[bdosborn]

My LiFePO4 runs about 13.7V when charging, it doesn't rise to over 14V until it's almost charged. Here' a graph of the voltage versus current for my main charger, the Renogy should be similar.


The Renogy should be charging with your LiFePO4 at 13.2V, or at least mine would be.
Bruce

[John61CT]

At rest isolated the bank should not be allowed to get much below 12V unless the last 10-20% SoC% is needed for an emergency, will reduce longevity.

Discharging at a high C-rate maybe, below 12V is OK for a short time, you want to see V bounce back above 12V after isolated from load.

As I said 100% Full will be 13.3-13.4V again resting and isolated.

Charging voltage can go to 13.8V I would not go over 14V unless unadjustable BMS required that for balancing (bad purchase).

Assuming getting maximum longevity is a priority that is, the latter factor is less critical than the former.

[RJ Howell]

My LiFePO4 runs about 13.7V when charging, it doesn't rise to over 14V until it's almost charged. Here' a graph of the voltage versus current for my main charger, the Renogy should be similar.


The Renogy should be charging with your LiFePO4 at 13.2V, or at least mine would be.
Bruce

That's where I'm at with this. It should be charging now, just can't prove it yet ( green light or fan running would be nice). I leave in the morning for a trial run in the new camper and will have the system online. I can meter usage and have a good idea of what to expect voltage wise. Intent is to be metered on both in and out like I did with my solar setup, just. not there right now and wanting (Jonesing) to get out there! I do believe this unit is DOA... hoping not.

[RJ Howell]

At rest isolated the bank should not be allowed to get much below 12V unless the last 10-20% SoC% is needed for an emergency, will reduce longevity.

Discharging at a high C-rate maybe, below 12V is OK for a short time, you want to see V bounce back above 12V after isolated from load.

As I said 100% Full will be 13.3-13.4V again resting and isolated.

Charging voltage can go to 13.8V I would not go over 14V unless unadjustable BMS required that for balancing (bad purchase).

Assuming getting maximum longevity is a priority that is, the latter factor is less critical than the former.

John, please, confine yourself to others posts. Going below, even close to 12v, on any battery we use is bad. I do not wish to argue with you or have you polute a thread I have begun. I Kindly ask you ignore my posts, please. You wish to take this up with me, PM me and relive the group from further disruptions.

[John61CT]

Actually you are 100% correct, there is no disagreement between us on that point.

It will not "damage" the battery in a sense that can be determined in the short term.

But it will reduce longevity by a lot, as I clearly stated.

You may get 7000 or even 10000 cycles from an LFP bank if you on average only discharge to say 50% DoD

but get less than 3000 going down to 90% average.