Good Sam Club Open Roads Forum: Renogy DC-DC Charger UPDATE 2 Test
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Renogy DC-DC Charger UPDATE 2 Test

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next
KJINTF

West

Senior Member

Joined: 09/04/2010

View Profile



Posted: 02/28/21 06:54am Link  |  Quote  |  Print  |  Notify Moderator

Not sure about the wiring of the Renogy but would assume it is similar to my Victron 12-12 Orion-Tr 30amp. The "-" connection to the source and load are isolated on the device, however can be connected together and do get connected together when the source and load share a common "-" ground.

Question for you guys
Anyone find a way to adjust the output/load current of a DC-DC converter?
Temporarily lowering the charge voltage does the job but is not as "clean" as desired.
The Bluetooth app does not offer any current adjustment that I can find only a custom voltage charge profile.

I charge a 200amp LiFe four cell prismatic home brew battery which will easily take the full 30amp from the DC-DC charger thus consuming 40+ amps from the source. My desire is to throttle back the charge current at times when the solar is not doing enough to keep up. The solar charges a 200amp PB battery bank. Don't care if it takes longer to charge the Li. I do not want to see my Pb bank get discharged while charging the Li bank. Yes I understand I could set the source cut off voltage high enough to eliminate the possibility of too much discharge but again it is not a "clean" solution and would cause the cycling on/off issue.

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 02/28/21 07:06am Link  |  Quote  |  Print  |  Notify Moderator

The Renogy one has a current-limiting feature that cuts the current to half. Don't know about other ones.

"The DC-DC battery chargers feature 50% current limiting from the rated specification when connecting the LC Terminal to a 12V source. Current Limiting is instant and recommended to be connected to the same location as the D+ ignition cable. Alternatively, you can toggle
current limiting to your liking by connecting the LC terminal to starter battery positive terminal. In this fashion, current limiting will always take until removing the LC wire from the battery terminal to revert to the normal amp rating. Use 18-16AWG copper cable for the LC terminal
and you may need to splice your own connections for the other cable end depending on your connection point. "

I am not clear on the issue in the above post with the Victron or what other reason you would want to limit the current. It could be like other chargers, if it does more than the battery spec allows, such as more than 30% on an AGM. I had to not use my 55 amp converter on a single 100AH batt for that reason, but it was ok with two 100s in parallel.

* This post was edited 02/28/21 07:15am by BFL13 *


1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.

KJINTF

West

Senior Member

Joined: 09/04/2010

View Profile



Posted: 02/28/21 07:11am Link  |  Quote  |  Print  |  Notify Moderator

" The Renogy one has a current-limiting feature that cuts the current to half. Don't know about other ones.

How exactly is this accomplished? Thanks! for your edit

I was hoping to get a fully programmable current limiting output. My Victron when "on" goes full throttle no way to limit the current, as far as I can tell without a voltage adjustment.

Been emaiing the folks at Victron so far it's been a one way conversation.

* This post was edited 02/28/21 07:22am by KJINTF *

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 02/28/21 07:24am Link  |  Quote  |  Print  |  Notify Moderator

KJINTF wrote:

" The Renogy one has a current-limiting feature that cuts the current to half. Don't know about other ones.

How exactly is this accomplished?


There is a connection for the LC wire on the output side of the unit. I don't know how "current limiting" is accomplished in converters and chargers, but I suppose this LC wire swaps to another component.

https://m.media-amazon.com/images/I/B13jMRZjsnS.pdf

KJINTF

West

Senior Member

Joined: 09/04/2010

View Profile



Posted: 02/28/21 08:53am Link  |  Quote  |  Print  |  Notify Moderator

BLF - Thanks for the response - sorry to have interrupted your thread

I received my answer from Victron
The Orion-TR Smart DC-DC converters - Do NOT have the ability to adjust output or input current. For my application this renders these converters useless.
I have to suggest folks stay away from Victron as a supplier of DC-DC chargers

StirCrazy

Kamloops, BC, Canada

Senior Member

Joined: 07/16/2003

View Profile



Posted: 02/28/21 09:17am Link  |  Quote  |  Print  |  Notify Moderator

BFL13 wrote:


With it finally working, with the truck running, I had 14.3 volts in the truck and 10.87 volts back in the camper at the DC inputs! (DC-DC will work down to 8 volts ISTR) That was using the 7-pin wires and no idea what the amps were on the input -maybe 25? Under 30 anyway since it was fused with 30a in Stud 1. Lots of voltage drop in those wires and connections.

Output was 14.1 and house batts 13.8ish, which would be going up over time to 14.7 (at the charger) with amps steady at 18ish in the Tri (so a 2a load +18= 20)

So it works and no amps tapering like with regular 7-pin. (down to 4.6 amps five minutes after starting the truck)


wow, thats quite the loss. where were you measuring the amps, at the truck battery or the camper battery? I m realy surprised with that much voltage drop your not getting a pretty hot wire.

Steve


2014 F350 6.7 Platinum
2016 Cougar 330RBK

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 02/28/21 09:18am Link  |  Quote  |  Print  |  Notify Moderator

No worries, thread is open ended. But the Renogy only cuts the current in half, and what if that is not the right amps? The dial a current add on would work with Victron or any fixed current charger.

Mex is the guy for such things--he uses light bulbs in the line. A dimmer switch isn't it? Not sure how they work. you want the same voltage but adjustable current. Portable chargers have current settings like 4/10/20/40 you can choose, but you want a dial any amps.

------------

I will be looking at the input side when I do the proper installation--I didn't feel for hot spots at the time. I want to use the 7-pin for the signal lights etc, but by-pass the connections through the pin# 4s. That would mean another quick-connect for that one wire for when you slide off the camper. The ground wire would still be through the 7-pin (for the signal lights etc), but reducing R of just the pos wire would help the circuit's total R.

I didn't leave it running long enough to know if the house battery would reach the Vabs set at 14.7v. Have to tidy up all that mess I did just to see it working. Solve all that in good time now I know what works.

* This post was edited 02/28/21 09:30am by BFL13 *

BFL13

Victoria, BC

Senior Member

Joined: 02/15/2006

View Profile



Posted: 02/28/21 01:31pm Link  |  Quote  |  Print  |  Notify Moderator

Update--cleaned up the installation, and tested it again--works a little better now. Batts full but ran MW on inverter to bring voltage down so the charger would see the need to do Bulk stage. Turned on truck engine idling, and turned on charger:

(Before test--DC input on, not connected to house batts, output voltage showed 14.7 briefly, then 13.5)

Input- truck 14.6v, input DC 11.7v
Output- DC 12.5v, Trimetric on batts 12.3-12.4v, 20 amps

after 10 minutes-
Turned off MW, letting charger bring up battery voltage-

Input- truck 14.3v, input DC 10.9v (getting warmer?)
Output- DC 14.63v, Trimetric 14.5v, 20 amps

went into Absorption Stage

Input- truck 14.22v, input 12.09v
Output- DC 14.64v, Trimetric 14.6v, 10.5 amps tapering.

I used a household light switch on the "ignition wire"--very handy to be able to switch the unit off and on. Unit is mounted on the inside of the closet on a side wall (house batts below the closet floor) so the output side is facing out and you can see the green light (and red light-hope not) Solar controller also in there on a wall. If it gets too warm, will leave closet door ajar.

On the input, I by-passed the 7-pin connectors for the charge wire and it did help with the voltage but only a little. It works so no need to do more AFAIK.

* This post was edited 02/28/21 01:45pm by BFL13 *

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 02/28/21 04:15pm Link  |  Quote  |  Print  |  Notify Moderator

BFL13,

I hope the switch is DC rated with arc fault protection.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

bdosborn

Colorado

Senior Member

Joined: 03/26/2006

View Profile


Offline
Posted: 02/28/21 05:06pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

BFL13,

I hope the switch is DC rated with arc fault protection.


Got a link?


2010 6.5'X11' TTT - Boxcar
Custom Frame, Poptop, AC, Espar Diesel Furnace, HW Heater, Sink, Shower, 12V-120V, LED Lights, TV and XM Radio, DVD Player, 300W PV Panels, PD 9140 Charger, Tongue Box, Filon Exterior, 1000W Generator, Patient Wife
Boxcar Build


Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > Renogy DC-DC Charger UPDATE 2 Test
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.