I want to explore the idea of a single 100AH battery with all the bells and whistles connected to my alternator and a solar panel. This all seems pretty standard but it’s proving surprisingly hard to find a good how to.
AGM under the hood and LiFePo4 in camper. Needs to take solar, be isolated from the starting battery, have a charger, have all the safety things built in so it cant over charge, over heat, take a charge while too cool, etc etc etc.
Looking for the least amount of parts to get this done as well.
Lastly - while not needed, bonus points for the person who can tell me how to add shore power and inverter to this mess should I decide that seems necessary…
I didn’t use Victron but I assume they have similar offerings as Redarc. This still should apply though and hopefully be helpful.
I went with the Redarc bcdc1225 dc-dc charger. It’s got all the features you mentioned and can even be mounted under the hood if you want, I mounted mine in the camper to be as close to my 100AH lithium battery as possible. It has a solar mppt charger built in as well. The wiring is pretty simple, run a positive and negative from the starter battery back to the charger then charger to battery.
Inverter is easy, pick a well reviewed pure sine wave inverter and attach to battery. I forget what brand I got but it’s a 600 watt and all I use it for is to charge my laptop. Size it according to your needs.
For shore power I have a 10 amp Victron charger and an extension cord. I’ve never used this while out and about though, only at home to charge the battery if needed. I never camp anywhere with any kind of facilities but it’s always in the truck just in case.
Regarding the cold weather part, the BMS in my battery has a cutoff that won’t allow charging under 32 degrees. I think most of the lithium batteries from the top companies have this, I know BattleBorn does.
I did all of this super simply and efficiently although you will pay for it…. National Luna DC25 with a 100ah lifopo4 battery connected to solar on the roof, to the alternator and shore power via charging port with a NOCO charger and Bob’s your uncle
Perks of a contained unit like the Luna is I can take it out and put it in the garage, but that’s gonna be $2k easily before I am done. It also doesn’t fit in my space so I would have to rearrange or something…
I have some wall space for controls and a nice little out of the way space for a battery in a battery box but then I am doing a permanent install as I would definitely not be taking it in and out. This is the other option…
As for Redarc - I have a redarc BCDC controller already under my hood in a dual AGM battery setup. It seems like it works pretty well but the AGM house battery is a total POS and doesn’t work for my needs. It is only 2 years old and instead of shelling out for another, I figure I am going to just do what everyone else in the van/camper/rv world has done. So why Victron over redarc? Well from what I have heard and read, it is simply better quality and the only real advantage the redarc has is that you can leave it in your engine bay.
As of right now I am torn on if I will keep both dual battery systems and just have two charging systems - or just ditch the under the hood one and try to sell the kit that I got for that setup. It’s a sick kit but the AGM battery just blows and can’t put the good batteries under the hood.
Back to the question I asked tho - cuz someone’s sitting on the answer:
Battery (Battleborn 100ah 12v)
Solar Controller (Victron part #?)
DCDC (Victron part #?)
Smartshunt (Victron part #?)
Isolators and all the other stuff to make this work?
I know there are a million posts on house electrics but when I find the good write ups they are for like 8000ah 2kw solar with enough inverters to run a 3phase mill off of - as are many of the write ups I can find like explorist.life for example. Just looking for the simplest way to do what I am trying to do - and maybe that is just another redarc.
From what I’ve read redarc and Victron are equal on quality but Redarc is usually more durable and can handle extreme environments. Either is probably totally fine, whatever floats your boat.
There are 2 victron smart shunts. One is water and dust proof. Sends all the info to your phone. They are awesome. Can’t you repurpose the Redarc DC DC charger and use it as a solar controller and it lives under the hood? I’ve dealt with Victron forever in my yacht management business, the way it all integrates is awesome. Not sure you need a Bluetooth battery and a shunt, although I’ve never looked at what info the battery gives you. I’m not a big power user and will never need AC, so I can’t see investing in a whole system.
To get me through, I just got a Dr. Prepare dc power station, basically a 100ah lifepo with a little box that has a solar controller, various DC outputs and a 10 year warranty. It’s limited to a 100w panel, so I got a folding one. That may be limiting, but it’s a regular battery, so I can expand as I figure out what way to go if I need to.
I do want to examine the possibility of putting a vented/insulated/? box for a lifepo under the hood. I have a thermometer with a remote sensor on the way to watch what goes on under there. I have one, but its for a fridge and stops at 100º. I don’t want stuff in my bed when I’m in work mode, but also want house power all the time.
I went renogy over the others on the charge controller, their little all in one controller is pretty slick. Solar as well as dcdc and monitoring.
Take a look at SOK for the battery, quite a bit cheaper and great quality, also user serviceable if ever needed. Their 100ah with heating pads is like $600.
Just my 2 cents.
@the_philxx I did the Victron build, but with two batteries. here’s the specific build post where I talked about added my own heaters to the batteries. It’s worked great so far. battery heater GFC post
here’s the invoice from Battleborn (dragonfly energ). I already had a battleborn 100ah battery in my mini camper, which I stole. going to replace it with a cheap chinese knockoff, because I don’t use the mini camper that much anymore.
@the_philxx I’d go with the KISS theory. Look for an all in one MPPT/DCDC charger like the unit offered by Renogy. Add the Bluetooth module for $40 and forget about the Shunt. Because of using a DCDC you don’t need an isolator, that does it for you. Make sure you confirm your Alternator draw and available amperage.
You should be able to build this out for just over $1000 if you go with a cheaper 100ah Battery.
2 x ANL 200A fuses $100
Cabling/connectors = $200
100Ah Battery = $600
MPPT/DCDC = $300
Solar Panel = $150
The key with cold weather is knowing that Solar doesn’t work that great in the winter unless you’re further south. So, personally 100W solar does nothing for me and was a waste of money. If I were to do it all over again, I would not put solar on my rig and just use a DCDC charger.
There are quirks with some of the MPPT/DCDC charger combo’s. I can’t remember who the member is, but there is a way to trick the units to provide a charge when the temp drops.
That’s the big thing to consider. Some MPPT and DCDC chargers have thermistors that disable charging when in Lithium mode if the temperature is 5*C and below.
This is a problem if you have a battery with a built in heater. Also, the heater requires ‘x’ amount of stable current to turn on the heat element. So in the case of Renogy’s battery that is 3A. Also a thing of note, is that if you intend to have a heated battery with the idea of keeping it warm when the rig is parked; when the battery is 100% charged the BMS will not request a charge (in the Renogy case) until the source charge voltage is 1V (they say .5V) greater than the Lithium. So in my case, that is generally when the battery self discharges to about 86%.
I’ve only had the battery go into discharge disconnect once while it was in use because the battery temp reached -20*C. From what I could find, non of the companies offer a solution that works perfectly in cold weather. I’ve looked at changing my system but found that it’s just a new and confusing set of problems I’d introduce.
Personally, I’d buy what makes your brain happy then learn to adapt it to work for you. Cold weather and batteries will never be a happy medium.
The one big difference I have is I won’t be leaving the car unattended for long periods of time so running the engine and firing up the heater are options. I believe (if I recall your other posts) that many of the challenges you ran into were with leaving the rig for a week and finding the battery uncharged, battery heater not working, etc.
Fortunately I think if I just let the car run for 15 minutes and blast the diesel heater, the this will top off but more importantly - the 100ah should be plenty for most of my weekend getaways and can recharge via shore power at home.
Who knows - these are all considerations and I just want a simple solution that doesn’t light me on fire in the night in winter.
You’re right, that’s what was happening. I’ve now come to accept that as it’s not a game changer. As long as everything is fused right you should be able to not burn your truck to the ground.
If I run my heater all night (5kW) it brings my battery down to 50% when set to 17C and it’s -18C outside. So it takes about 2hours of engine runtime on a 20A DCDC charger to bring the battery back to 100%. Since I rarely (this season) use the rig and not drive it that day, I’m always able to get my battery back to at least 80% which gets me through the night easily on 100aH. I’m usually also charging an iPhone, Sock batteries, and other odds and sods.
