Hi all,I finally have the dc to DC 20 amp Renogy installed.It works, but not quite as I expected.It appears to not "like" solar much--cutting way back on amps, even though the dip switches are set to 14.7 volts output on the Renogy.I do have manual control of the solenoid that feeds the Renogy.It was distinctly NOT an easy install. The only place for it was under the passengers seat. I added some spacers under the unit as it appears there is an additional heat sink on the bottom of the unit.Installation was with #8 wire.I did turn the Renogy on after a night of boondocking where the "house" bank got down to 12.3 volts. At idle, charging was about 10 amps. At highway speed that went up to about 19 amps. I did not have a long drive that day.I can still do a "poor man's" boost system should the starter battery ever be low.The Renogy did stop the energy drain from the Telcom "house" jars to the engine. On the other hand, I could have done that with the original upgrade which gave me a dual charging path to the "house" bank--with manually controlled solenoids.I think this may be the last "tech" upgrade I do.

pianotuna wrote:Hi all,I finally have the dc to DC 20 amp Renogy installed.It works, but not quite as I expected.It appears to not "like" solar much--cutting way back on amps, even though the dip switches are set to 14.7 volts output on the Renogy.I do have manual control of the solenoid that feeds the Renogy.It was distinctly NOT an easy install. The only place for it was under the passengers seat. I added some spacers under the unit as it appears there is an additional heat sink on the bottom of the unit.Installation was with #8 wire.I did turn the Renogy on after a night of boondocking where the "house" bank got down to 12.3 volts. At idle, charging was about 10 amps. At highway speed that went up to about 19 amps. I did not have a long drive that day.I can still do a "poor man's" boost system should the starter battery ever be low.The Renogy did stop the energy drain from the Telcom "house" jars to the engine. On the other hand, I could have done that with the original upgrade which gave me a dual charging path to the "house" bank--with manually controlled solenoids.I think this may be the last "tech" upgrade I do.19 amps driving that not bad at all from a 20 amp setup. I wonder if the tapering amprage is because your using LA batteries who taper off amps as they charge and since you have solar going the renogy is getting a higher voltage back and tapering off. everyone I have seen tht uses them so far is using them with LFP batteries. Steve

Why under passenger seat? It should be as close to batteries that it is charging as possible.

Slownsy wrote:Why under passenger seat? It should be as close to batteries that it is charging as possible.no room needs to be cool and dry.

The unit got a work out today as I stopped to use the microwave for lunch.The micro draws 176 amps.When I started to drive the dc to DC was charging at 19.5 amps. Therefore the location works.

pianotuna wrote:It appears to not "like" solar much--cutting way back on amps, even though the dip switches are set to 14.7 volts output on the Renogy.May need more panels to fully drive the solar. Have read something about not combining power inputs. Possibly more limits with solar. I would have recommended staying with the existing controller and just get the straight DC-DC.I like separate components over these all-in-one outfits.

dc to DC Renogy charger | Good Sam Community

12thgenusa
Explorer
Oct 16, 2022
Have you measured your input amps? I've read these take 30 amp input to produce 20 amps at the battery.

I'm thinking of installing one for my 5th wheel. Concerned about the extra 30 amp draw on the alternator, long run of large gage wire (at least 6 ga) and an additional disconnect on the tow vehicle.
pianotuna
Nomad III
Oct 15, 2022
time2roll,

The dc to DC charger is stand alone. I use a Blue Sky 30 amp charge controller. It is set at a lower output voltage than the Renogy.
StirCrazy
Moderator
Oct 15, 2022
pianotuna wrote:
The unit got a work out today as I stopped to use the microwave for lunch.

The micro draws 176 amps.

When I started to drive the dc to DC was charging at 19.5 amps. Therefore the location works.

what was the voltage it was putting out?
time2roll
Nomad
Oct 15, 2022
pianotuna wrote:
It appears to not "like" solar much--cutting way back on amps, even though the dip switches are set to 14.7 volts output on the Renogy.
May need more panels to fully drive the solar. Have read something about not combining power inputs. Possibly more limits with solar. I would have recommended staying with the existing controller and just get the straight DC-DC.

I like separate components over these all-in-one outfits.
pianotuna
Nomad III
Oct 15, 2022
The unit got a work out today as I stopped to use the microwave for lunch.

The micro draws 176 amps.

When I started to drive the dc to DC was charging at 19.5 amps. Therefore the location works.
pianotuna
Nomad III
Oct 15, 2022
Slownsy wrote:
Why under passenger seat? It should be as close to batteries that it is charging as possible.

no room needs to be cool and dry.
Slownsy
Explorer
Oct 14, 2022
Why under passenger seat? It should be as close to batteries that it is charging as possible.
StirCrazy
Moderator
Oct 13, 2022
pianotuna wrote:
Hi all,

I finally have the dc to DC 20 amp Renogy installed.

It works, but not quite as I expected.

It appears to not "like" solar much--cutting way back on amps, even though the dip switches are set to 14.7 volts output on the Renogy.

I do have manual control of the solenoid that feeds the Renogy.

It was distinctly NOT an easy install. The only place for it was under the passengers seat. I added some spacers under the unit as it appears there is an additional heat sink on the bottom of the unit.

Installation was with #8 wire.

I did turn the Renogy on after a night of boondocking where the "house" bank got down to 12.3 volts. At idle, charging was about 10 amps. At highway speed that went up to about 19 amps. I did not have a long drive that day.

I can still do a "poor man's" boost system should the starter battery ever be low.

The Renogy did stop the energy drain from the Telcom "house" jars to the engine. On the other hand, I could have done that with the original upgrade which gave me a dual charging path to the "house" bank--with manually controlled solenoids.

I think this may be the last "tech" upgrade I do.

19 amps driving that not bad at all from a 20 amp setup. I wonder if the tapering amprage is because your using LA batteries who taper off amps as they charge and since you have solar going the renogy is getting a higher voltage back and tapering off. everyone I have seen tht uses them so far is using them with LFP batteries.

Steve

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