Renogy DC-DC Battery Charger Review: 'Smart' Alternator Charging for Solar Batteries!

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[WillProwse]

If you are using this system to charge a custom built lifepo4, use the custom charge profile parameters.








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FTC Disclosure Statement and Disclaimers:
Every video includes some form of paid promotion or sponsorship. Some links on this youtube channel may be affiliate links. We may get paid if you buy something or take an action after clicking one of these. My videos are for educational purposes only. Information is subject to change/update at any time. Electricity is DANGEROUS and can kill. Be smart and use common sense :)

DIY Solar Power with Will Prowse is a participant in the Amazon Services LLC Associates Program,
An affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com

[KingTesticus]

I can relate to that excitement when something works the way it's supposed to.
Thank you!
Adding this to my favorites..

[robashcroft]

The current limiting function is useful when the unit is mounted in a caravan/trailer and you want to use the existing wiring on your trailer plug. Here in Australia, the largest current you can put through a 7-pin trailer plug is 15amps, which would exceed the current draw of the Renogy 20amp DCDC charger (which can be up to 30amps). Reducing the output of the Renogy DCDC Charger using the limiting function would reduce the output to 10amps, which would mean a maximum of 15amps being drawn through the trailer plug. I have one of the Renogy 20amp DCDC chargers installed in a camper trailer, and configured in current-limiting mode this way

[geebroni]

Great video. Wired my 20 amp Renogy D+ wire to a marker light to turn unit on. Simple and safe to alternator since my lights aren't turned on until after engine is running.

[solosailorsv]

Based on your extensive videos and dedication to technical testing, I bought, built, and installed a LiFePO4/Daly system with the DC/DC charger to the SLA for the alternator, with Solar charging switchable to either. AWESOME performance! Solar charges the LiFePO4 bank faster and no-voltage sag is wonderful (very low Internal Resistance gains).
THANK YOU WILL

[RenogySolar]

Thanks for the feedback, Will! We can't wait to see how they do for you in the long run! Temperature sensors are coming soon!

[dbru]

Great video. You could add a 12v dc "time delay relay" on the ignition circuit to delay power going to the unit, giving your alternator a few extra seconds to power the charger. Simple to install.

[Scrambler]

Great review, on the delayed start of charging, seams like a inline switch could be used to control when the charger starts on the ignition wire.

[TrumpElection]

Great review mate. You are correct, not everyone is schematic smarties. By illustrating the simple set up of Renogy, you have made this process extra simple to it's simplest form. Great job!

[micjakes]

Finally found it! I was going to use the Battery Doctor isolator and use a step up transformer from 12v to 24volts to charge my battery bank. Thanks again Will.

[Roy-ijwq]

Will - The current limiting switch allows you to match the charging current to specific conditions. For example, if you have the 40 amp charger and your batteries are fully charged, you may want the lower 20 amp current to just run the refrigerator on A/C when driving. The lower current also requires less power and the alternator doesn't have to work as hard resulting in better fuel economy. You may also want to limit the current when driving in mountains or excessive heat. I plan on installing toggle switches on my 60 amp charger that will allow me to turn it off when not needed, 30 amps when the batteries just need to be topped off and/or I need to run the refrigerator, and 60 amps when I need to charge the house batteries. Also, you can use the same ignition terminal for both. If the charger detects any current on the CL terminal, the current is limited.

[Formulabruce]

Will, your RV has a V-10 in it!! No wonder you are so good at Solar !! Keep up the great videos, this one is great info!

[pkc]

Thank you for all the information will you are a very knowledgeable young man. 😊

[Bf-ldvn]

Always enjoy your videos and reviews - you exhibit competence and speak in a manner people can understand. Keep up the good work!

[jondavidmcnabb]

Damn it Will, you’re so smart and knowledgeable it hurts to watch other people’s videos. If you and Jehu did a video on building a DIY Solar/Battery generator it would get monster views. Jehu is good, but he tends to skip steps or concatenate videos. Keep up the excellent work!

[JOHNMORIN]

Now you realy got something THERE I have been looking for many years THANK YOU I have been using 700ah of Lifepo 4 cells. What adifferance from our old L16 cells with enoughf sun we do not need to till we go for days without sun, then it takes sometimes 4 hrs at low amprage to effectivly re-chrage them from our 180amp HD alternator with EXTURNAL Home made regulator. We keep our amiture voltage down to 2-3 amps 13.5 volts. This is going to alow us much more stability.... THANK YOU (ps WE use a 3, 000 amp three phase rectifier to keep everything cool. no heat to hurt the rectifiers.internal diodes wer removed 3 phase output ) John in Milo, Maine 1000 points at least...

[JoeBoutilier]

When I installed this in my cargo trailer conversion, I connected the V+ line to the tail light circuit in the trailer. So, when I start my truck, even though the alternator is supplying power to the input of the converter, it isn't until I turn on my tail lights that the converter turns on. As you suggested, it allows things to heat up and be "ready" before I switch on the charger. I thought about using ht etail light circuit as a switching source rather than running a separate control wire back. It allows me to run everything through the standard trailer connector.

Love the channel, keep up the great content.

[stevenpolitte]

Use the D+ terminal in conjunction with a small timer PLC to delay DC-DC connection when the ignition switch is turned on.

[sbvictory]

Thanks Will. I bought the 40A unit. My manual says the LC wire input limits the current to 50% (not 12.5%). This seems much more useful. I plan to have a switch in the car so I can just select 40A (switch off) or 20A (switch on). I have a high amperage alternator, but it depends upon how discharged my battery is and how long I'll be driving between campering sites whether I use 20A or 40A. Also, if my alternator won't reliably handle 40A, I could probably still use the 20A. Of course if that's the case, why didn't I just by the 20A instead? I didn't know that info ahead of time. I guess I'll see how it works. Thanks again for your videos!

[maramé.r]

The Votronic DC-Charger (30A) also has alternator voltage sensing which can be used as an alternative to using the ignition D+ signal to initiate charging. It has a LiFePO4 charge profile, includes a temperature sensor and is compact in size