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  • New lithium batteries, with lead acid backup

    Thank you to all of you that wrote about your experience of installing new lithium batteries; especially Howard howson , Brian Country Campers and Jim MidwestCamper . I learned a lot about how to make the system decisions and how to install the components. I followed your posts thinking I would make the conversion when my current bank of two Trojan 6V batteries needed to be replaced. Unfortunately, a change in health circumstances changed our energy budget. My wife needs to use an oxygen concentrator at night, at least for a while. I measured how much energy it uses through the night, and it would drain our current batteries when boondocking. Since that is our preferred camping option, I needed to increase our battery capacity. I added a third 100W solar panel, but there will be circumstances where solar can’t keep up with our energy needs. In these cases, if I have to use the generator, I want something that would quickly and efficiently recharge the batteries. The DC-DC charger also became a very appealing component to efficiently charge while driving.

    An important trip we make each year now is to the Southwest after Christmas. This involves leaving and traveling in below freezing temperatures. I decided to keep a 12V lead acid battery as backup, and make sure the components will charge both lithium and lead acid, and be easy to switch between them. With experience, I may find it is not necessary to keep the lead acid. Now, I’m more comfortable knowing I have the ability to charge an energy source in freezing temperatures, and I have it, so why not keep it?

    This is what I settled on:
    SOK Battery 12V 206Ah LiFePO4 Battery (2). Will Prowse is very positive about their quality and construction. It has a good BMS that will shut it down if it gets too cold, or too low on energy. The batteries are the same size as the Trojans they replace, and are less weight. They also have Bluetooth (I can see the voltage and temperature). For lithium, they are reasonably priced. I’m using 2AWG to connect the batteries, converter, and inverter.
    PowerMax Converter PM3 LKL 100A. The 100A capacity will provide the lithium batteries all they will take when using the generator. A simple switch changes the charge profile to lithium or lead acid.
    Victron Energy Orion-Tr Smart 12/12-Volt 18 amp 220-Watt DC-DC Charger, Isolated (Bluetooth). I chose this because it can be controlled from my phone through Bluetooth, including changing the charge profile between lithium and lead acid. It was easy to wire in, I used the wire from the 7-pin connector with the truck. I used 8AWG to the charger, and 6AWG from it.
    Victron Energy SmartShunt 500A Bluetooth Monitor. This has a nice information package accessible through an app on my phone. It monitors voltage, watts charging and discharging, cumulative Ah, and some other things.
    I tested to make sure everything is working. The real test will come in a couple weeks when we head north for some summer camping.

    Again, thanks,
    Dave
    2016 Reflection 27RL
    2015 Silverado 2500HD 6L
    B&W Patriot 18k slider

  • #2
    Dave27

    Dave,

    Looks like you have a great set up that will sever you well. I really like the SOK batteries and would have used them if I did not already have the Lion batteries. You will like the Lithium capabilities and the DC-DC charger is a good add on. Hope all goes well and I am sure you will keep us up to date.

    Brian
    Brian & Michelle
    2018 Reflection 29RS Oct.2017 build date, EMS-HW50C , Lippert Remote
    2015 Chevy 3500HD CC LB Duramax , Reese Elite 18K
    630 ah battery, Victron Multiplus 2, 800 watts solar

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    • #3
      Dave,

      It looks like you have made a sound decision on a system that will meet your needs. Keep the contacts clean on your 7 way connector and use dialectic grease to maintain good contact.

      Best wishes for good health and enjoyable camping.

      Jim
      2017 Imagine 2600RB
      2015 GMC Sierra 4x4

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      • #4
        This is to follow up on how our new lithium batteries, converter, smart shunt, and DC-DC charger have worked out. We camped for about nine weeks, in two separate trips, in northern Michigan and northern Minnesota. Almost all of it was in national forest and national park campgrounds with no electricity, and all well shaded by the northern Great Lakes forests. We love these places, but we cannot keep up with our electrical demand with only the solar panels. We get some charge, but with the shade, it’s not very much.

        The increased battery capacity is great, we can go for days with the minimal solar charge before we need to run the generator. If I wait until the lithium batteries are less than 20%, the new converter will feed over 90 amps into the batteries. This significantly reduces the amount of time I need to run the generator (in my ideal world, I would never run it). I found that the amount of charge the batteries will take does vary with the voltage. If I charge them when they are only moderately discharged, the converter will still feed them 40 to 50 amps. The amperage will decrease as the batteries fill, but it generally is not very much. So I am very pleased with the SOK lithium batteries and the Powermax converter/charger.

        The Victron smart shunt is wonderful. I can monitor what is going on with the batteries from the truck while we are driving, and in or near the camper while camping. When I was testing components, it was nice that I could graph how the amps and voltage were changing. See link: https://gdrvowners.com/forum/operati...-dc-dc-charger

        The Victron DC-DC charger didn’t work out for us because I didn’t want to run a new wire from the truck back to the camper. A technician told me they have seen problems when someone tries to feed it through the 7-pin connection. I like the Bluetooth connection, and the automatic sensing if the truck is running, but returned it. The story is in this link: Victron DC-DC charger not charging very much - Grand Design Owners Forums (gdrvowners.com)

        I replaced it with the Renogy 20 A DC-DC charger. I used the same hookup through the 7-pin connection, I just had to add a wire from the running lights to act as the switch to turn it on. It works well for us. I get 13-15 amps while we are driving. This will be especially nice when we have longer drives after camping in cloudy or shady conditions. It also does a great job of "topping off" the batteries when they are close to full.

        I am very pleased with how everything is working. We are able to meet the increased electrical demand we currently have, and continue to camp in rustic campgrounds, with minimal reliance on the generator.

        Regards, Dave
        2016 Reflection 27RL
        2015 Silverado 2500HD 6L
        B&W Patriot 18k slider

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        • #5
          Dave27 Dave,

          Awesome post and its nice this worked out so well.

          We used to camp in the UP and the upper lower in Michigan. Beautiful campsites.

          Jim
          2017 Imagine 2600RB
          2015 GMC Sierra 4x4

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          • #6
            Dave glad it's working well for you. A lot of the points you raised we brought up to owners at the national rally, specifically solar production in the shade and the advantage of a larger converter in reduced generator run time. It's nice to see real world examples other than our own.
            Neil Citro
            2018 Reflection 28bh
            2019 F350 6.7L Long Bed Crew Cab

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