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Renogy DC DC Charger w/ MPPT

Hi, I have a Sprinter 2016 with smart alternator (E33 Battery management on VIM datacard). I know I have to install it with the ignition wire to a positive (only on when the engine is running), my question is:

1. If I put a switch inline the smart alternator wire to the DCC50S, in theory I will be able to disconnect the alternator charging (what I want to be able to make). What I'm thinking is, if the DCC50S detects no volts on the wire (ignition wire) but detects an increase of the voltage of the main battery, it can "think" that I don't have a smart alternator and start charging the leisure battery even with the ignition wire OFF?
I’m curious what you’re trying to accomplish.
 
Yes it should begin charging whenever it senses a high enough voltage from the starter battery. A switch or relay on the positive wire from the starter battery to the input of the charger would work though.

Thanks for the answer! So I have to install this switch from the main positive (starter) to the main positive (leisure), I had preferred to install a switch on the ignition wire (little on/off switch) instead of a big isolator. Thanks Reed!
 
I’m curious what you’re trying to accomplish.
With 600W of solar on the sprinter roof, for the 90% of the days I'm fine (more energy than I need) I only want to charge from the alternator if I really need it (like a lot of days of clouds...), I believe that in this situation the alternator is going to be better, and the lifepo4 batteries a bit better to. Have a nice day!
 
Putting a circuit breaker between your starter battery positive and the charger, gives you the ability to switch off alternator input and doubles as needed protection. The circuit breakers shown in Will’s Diagram are not very big. If you switch off the Ignition On wire, you’re still going to charge from the alternator when your alternator is putting out high enough voltage. I don’t know exactly what that voltage value is.
 
Thanks for the answer! So I have to install this switch from the main positive (starter) to the main positive (leisure), I had preferred to install a switch on the ignition wire (little on/off switch) instead of a big isolator. Thanks Reed!

Yes, the charger sits between the two batteries of course, so the switch would need to be between the starter battery and the charger.

The idea of a circuit breaker is a decent one if you aren't going to be using the switch often, as switching isn't their intended purpose, though it might be harder to place it in a location that provides protection while being accessible. Fuses and breakers should placed close to the ends of wires.
 
I hope to have a different outcome with slightly different requirements. I only really need the BT2 to configure the charging parameters. I have a Victron monitor and my BMS also provides power monitoring. Did you have experience with the DCCS50 as a charger sans the BT2? I hope it works well as a charger. I also purchased one of the progressive dynamic lithium converters before I found out it is really a power suppoly and not a charger. I think I will end up connecting it to the solar input so I can use the charging profile of the DCC50.

Good luck with your RedArc and I hope you are able to return the Renogy gear.

Louis
I too only wanted to use the BT2 to configure the charging parameters. The Boost Charge voltage can be set successfully. The Float Charge voltage can be set successfully. But there is no rhyme or reason to the displayed mppt modes, Bulk, Boost, Normal on the BT-2 device. In all the time That I have used the device, Boost set at 14.4v, Float set at 13.8, the device has never strived to meet the float set at 13.8v. There is no definition for the remainder of the parameters available to set using the BT2 (High Voltage Disconnect, is this for the STARTER battery or HOUSE battery voltage) Thus comment applies to most of the other parameters the BT2 devices allows you to set. And there is no mention of parameter interdependence.
I have a Victron BM to monitor the battery with, no need to use the BT2 for this function (It does not have a shunt, so the SOC monitor display is a joke). There is also NO response from the Renogy customer service requesting definition of parameters and their interrelationships.
 
Hi, I have an Renogy dcc50s in my RV for one year now, this winter I want to add an 230V 14,6V/40A Li charger to my system.
My bms is 123smartbms with extern relays.
Anyone have some suggestion where is best to connect it, want it to charge startbattery when service is fully charged?

Peter from Sweden :)
 
Will, is there a Victron system that will also trickle charge the car battery like this one?
thanks!
Gilbert
Probably not something specifically designed to for that, but you could probably figure out a way to design your system to do it.
 
Probably not something specifically designed to for that, but you could probably figure out a way to design your system to do it.
My van will sit for weeks at a time as I spend 4 weeks overseas and 4 weeks state side. That is why I find the trickle charger option interesting despite my Sprinter having the OEM aux battery.
 
For that use a little solar powered battery tender is probably the cheapest easiest thing to do.

But this person wants to switch their SCC output to their starter battery and change the charge profile each time, if you wanted to do that.

Thread 'Charge house AND starter battery from solar' https://diysolarforum.com/threads/charge-house-and-starter-battery-from-solar.16823/

I'm the OP of that thread. I agree, a solar battery tender would be easiest and probably cheapest. For me, I'm looking for a more elegant solution :)
 
Anyone seeing their charger stuck in “current limiting” mode as displayed on the DC Home app? I have a DCC50S hooked up to an 100aH Renogy LFP and for some reason it is stuck charging at ~60W/~4aH no matter if I use the 150W solar panels or alternator. I managed to charge up to 10aH with my solar and used to display MPPT / Boost on the status, it looks like it’s stuck into some sort of protection mode. I have tried to discharge the battery down to 80% SoC but it still does the same.
I have tried fiddling with voltages/max charge currents via DC home settings, unplugged to “reset” it, but to no luck.
Any clues? I appreciate the help.
 
Hi, is there already a decent meter / monitor out there? Which one are you using?
 
View attachment 1841
Finally reviewed it! People asked me repeatedly, and I was too busy with the solar shed. For the last few days, I tested it like crazy..

And I love it! I should have tested it months ago. Works extremely well, and it's fool proof. I pushed it to every limit, and if it cut off, it would restart a few seconds later.

Dead simple and easy to install for beginners. I really wish I had one of these when I was first adding solar to my RV. Super cheap too, compared to buying a voltage sensitive dc/dc charger and 50 amp mppt. Only downside is solar input voltage is extremely low, so 12v panels need to have branch adapter.

Key features (copied and pasted from renogy):
  • Designed to charge service batteries from two DC inputs—solar panels and alternator.
  • Built-in Maximum Power Point Tracking (MPPT) to maximize the solar power.
  • 3-phase charging profile (Bulk, Boost, and Float) ensures your service battery will be accurately charged at the correct voltage levels to 100%.
  • Built-in Voltage Sensitive Relay (VSR) for easy setup with traditional alternators.
  • Compatible with smart alternators (with variable output voltage).
  • Trickle charges the starting battery via solar panels if the service battery is fully charged.
  • Isolation of the starting battery and the service battery.
  • Temperature and voltage compensation features prolong battery life and improve system performance.
  • Smart Protection Features: battery isolation, over-voltage protection, battery temperature protection, over-current protection, overheat protection, reverse current protection, solar panel and alternator reverse polarity protection.
  • Compatible with multiple battery types: AGM, GEL, Flooded, and Lithium.
  • Compact with a sturdy design, it was built tough for all conditions.

I love it so much, that I created a new solar power package on my website! Dead simple blueprint:

Click here for parts list and schematics
Is there any single device that does all this aside from Renogy's two (50 and 30 amp) entries? I believe the Redarc does most, as does the CTEK, but neither (?) trickle charges the starter battery with solar, correct?

Thanks.
 
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