RV.Net Open Roads Forum: Renogy 20/40 amp DC to DC battery charger (UPDATE)

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

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 20/40 amp DC to DC battery charger (UPDATE)

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Sponsored By:
grizzzman

salt lake city, Utah

Senior Member

Joined: 12/07/2014

View Profile


Offline
Posted: 04/14/19 11:06am Link  |  Quote  |  Print  |  Notify Moderator

I just pulled the plug on a 40 amp unit. There Is a coupon for 20% off by giving them your email (the code is WELCOME10) At 179.99 for the 40 amp unit I could not pass it up! Look here
I will be using it as a backup charging source. With my solar, I have not needed an alternate source as of yet, but I believe the day will come.

I set this unit up
as a super jumper? I had an old set of 4 AWG 20-foot real copper leads. I installed new parrot beak clamps and cut them at a 6' mark. I installed the charger. I used a fuse as the on/off switch. I hooked it up to a sulfated battery (voltage was 12.34 and had been set in the garage for 6 months) The "smart" charger went from 14.7 to 13.8 (float) in less than five minutes. So much for the "smart" charger eh? Then I hooked it up to one that was charged a few months ago. (Its voltage was 12.50) ind it worked like it should.
The nice thing is it has Lithium settings. You can set a single voltage from 12.6 to 14.6 (see the manual) It can also be used as a power supply. The unit has dual cooling fans (bad if you are in dusty conditions as I am while camping) So keep that in mind. It is now in a pelican case under the dinette. Oh, there is an error in the manual about setting up some of the Li settings. they are working on correcting. For the price at least for me was worth it.

* This post was last edited 05/26/19 09:12am by grizzzman *   View edit history


2013 Ford F150 EcoBoost SuperCrew BFG KO2 10 Ply
2016 Rockwood Mini Lite 2504S. TM2030. SC2030 , Grape solar BT 40 Amp PWM
640 Watts Solar. Costco CG2 208 AH and Group 31 192 AH Batteries
400 Watt and 2000 Watt Inverter's hard wired.
Boondocking is my Deal

2oldman

New Mexico

Senior Member

Joined: 04/15/2001

View Profile


Offline
Posted: 04/14/19 11:08am Link  |  Quote  |  Print  |  Notify Moderator

Your link isn't working because you've included 'have a look' at the front of the url.

Have a look

landyacht318

Near a large body of salty water

Senior Member

Joined: 07/11/2007

View Profile



Posted: 04/14/19 02:56pm Link  |  Quote  |  Print  |  Notify Moderator

Seems like a good solution to vehicles that only allow mid to high 13v when the house batteries are still depleted. I don't really like the 40 amp limit but 40 amps seeking mid 14's is better than a vehicles voltage regulator saying 13.7v is fine and dandy for those depleted batteries.

grizzzman

salt lake city, Utah

Senior Member

Joined: 12/07/2014

View Profile


Offline
Posted: 04/14/19 04:57pm Link  |  Quote  |  Print  |  Notify Moderator

2oldman wrote:

Your link isn't working because you've included 'have a look' at the front of the url.

Have a look


Thanks!

landyacht318

Near a large body of salty water

Senior Member

Joined: 07/11/2007

View Profile



Posted: 04/15/19 12:36am Link  |  Quote  |  Print  |  Notify Moderator

The Illustrated wiring diagram shows they want to pull both + and - from engine battery, instead of takng the + right from the alternator.
The latter is usually a shorter circuit which bypasses the 'just thick enough' stock wiring from alternator to engine battery and without a DC to DC device in the middle, will deliver more voltage and thus more amperage to depleted house batteries.

[image]

This 'just thick enough' stock wiring will now be asked to pass those 40 more amps when the renogy DC to DC charger is seeking 14.7v on a depleted house battery.

Might want to add more copper in parallel to the 'just thick enough' OEM wiring from alternator (+) stud to engine battery (+), properly fused of course. Also upgrading the ground wire from engine battery to engine block could be considered wise insurance.

Since it is taking whatever voltage the engine battery is at, and stepping it upto the 14.7, well the renogy unit will not generate as much heat stepping up 13.6 to 14.7 as it would stepping up 13.2 to 13.7v. it might add longevity to the unit to reduce the amount of voltage stepping it has to do by lessing voltage drop on the 'just thick enough' stock alternator to engine battery wiring that the beancounters insisted was adequate.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 

Open Roads Forum  >  Tech Issues

 > Renogy 20/40 amp DC to DC battery charger (UPDATE)
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:

© 2019 CWI, Inc. © 2019 Good Sam Enterprises, LLC. All Rights Reserved. | Terms of Use | PRIVACY POLICY | YOUR PRIVACY RIGHTS