Redarc BCDC1225D or Renogy DCDC?

[PhotogTX]

Initially, I set up a second battery in my '95 4WD Suburban with a Redarc BCDC 1225D unit. Due to space limitations, I was only able to squeeze in a 72Ah battery under the hood. Since then, my project has morphed (grown) and I plan to construct a battery/component box to mount where a second row seat currently is. Plan is to go with 2x100W panels and a 100Ah SOK battery. Since I already have the Redarc, would it better to just stick with that or swap it out for the Renogy DCDC? How does a DCDC device (Redarc or Renogy) perform when it comes to functioning as an MPPT versus a standalone MPPT?

 

[HRTKD]

I would stick with the Redarc. An MPPT optimizes towards achieving the maximum power from the PV. A DC-DC charger does not.

Use a DC-DC for battery to battery charging, MPPT for PV to battery charging.

Here is a link to a more in-depth explanation.

Basics of Maximum Power Point Tracking (MPPT) Solar Charge Controller

Understanding Maximum Power Point Tracking solar charge controller - What is MPPT?, How MPPT works, How to choose MPPT charge controller for PV panels, How to set system configuration of MPPT charge controller

www.leonics.com

 

[fratermus]

would it better to just stick with that or swap it out for the Renogy DCDC?

If my Redarc were meeting needs (or projected to meet needs with the added solar) I would not pay money to swap it out. If you happen to have a Renogy DCC30/50 in the garage and want play with it I'd enjoy reading about the A/B testing with the units.

If you are looking to increase charging capacity we can talk about that, but IMO 25A is a pretty good charging rate for 100Ah of LFP.

How does a DCDC device (Redarc or Renogy) perform when it comes to functioning as an MPPT versus a standalone MPPT?

There is nothing about a combo unit that necessitates a weak MPPT algo. The only one I've read about having weak MPPT tracking was the Ctek D250-series. They were an early entrant to the field and solar wasn't their core competence.

I had hands on a Renogy DCC50 and the MPPT algo was robust. I've never heard anyone complain about Redarc's tracking, so I'd fire it up and see how she works. Report back for posterity.

 

[PhotogTX]

Thank you very much for the responses...I really appreciate the expert advice. Pretty sure I settled on going with a Victron MPPT, mainly due to its compact size since space is limited. I may use a NC relay linked to one of the Suburban's ignition sources to isolate the PV+ input so the Redarc handles the charging while driving and switching back to solar when the ignition is off. As I mentioned in the original post, my system is morphing and I keep getting different ideas in my head.

 

[dsb]

The redarc will do the job and is comparable to the Renogy, both can only use 12V panels as most 24V panels will exceed the max voltage of both units. this shouldn’t be an issue in your setup, as long as you use two 12V panels in parallel.

The main advantage of Renogy over Redarc is the Bluetooth, but the app is terrible.

Victron is great and has a really nice app but will only show data for solar input and loads not the charge coming from redarc, so unless you get a shunt it will only tell part of the story.

I don’t think you will notice much difference from an efficiency point of view between the three MPPTs

You can charge with both redarc and victron at the same time, as you are still under the max 50A but quite a bit more than the recommended 20A so it will reduce the life you get from the battery.