Lithium battery/solar design

I'm hoping for advice from someone very knowledgeable in lithium battery/solar applications. I would like to replace the lead acid battery in my 2013 Tacoma, with a lithium battery, and then tie that battery to however many other lithium batteries needed, that will be in my towed trailer, that are also tied to solar panels. I'm trying to figure out what is the best battery for the truck its self, what batteries (and how many) for the trailer. There will be two 150 watt panels permanently tied to them, but I would like the capability to add two more 100 watt portable panels. When needed. Also info on any accessories needed to regulate the power. No inverter needed, only 12v loads will ever be run. Anybody think they know the optimum design for this one?

 

What are you planning on powering? You need to figure out your usage before you design a system.

 

Welcome to TW Kevin

 

Put an AGM battery in the truck. 1-2 lithium in the trailer depending on your power needs. Use a Redarc dcdc or manager 30 for battery management / charge control

 

I'm trying to power a 12 volt AC unit in a heavily insulated 5' x 10' cargo trailer. My plan is to charge the system when the truck is running, when the sun is out, and top it off every night with a tickle charger while the trailer is home. I will be selling produce from the trailer during the day, so the AC will be on and off for up to eight hours each day. I probably only have room for three, or maybe four batteries in the trailer depending on the dimensions. Do they have to be the same battery that is in the truck? That would limit the size I think. There will be three hundred watts solar consistantly, (in full sun) and the potential to add 200 more watts with non permanently fixed panels. My biggest point of confusion is what will work for the necessities of the truck, (cranking power, size, cold resistance, and saftey) and also compatible with the remote battery bank, the solar, and the trickle charger.

 

Welcome to TW!

 

This is the controller I use. It's tied to a single 100W Zamp panel but can handle 1 more panel. I'm using an AGM battery but plan to upgrade from a Bosch AGM to a Northstar 103AH. Lithium is just not worth the cost yet IMO.

 

Was already mentioned but get a Redarc charger you can leave the lead or get an AGM battery and then use the red arc to power the lithium’s if that’s what you want. Many stack AGM batteries but the beauty of the Redarc chargers is you can mix battery types.

I’m waiting on my Redarc Bddc 1225D to arrive. Currently running 200watt solar on a Northstar 31M w/ a Victron controller and switching to 2 Northstar 35’s

 

Welcome to TW!

 

just put in a 27f agm in the truck. It’s a separate battery system from the trailer

for the trailer, you need to figure out your consumption and then work backwards. If you have constant sun, you don’t need tons of power storage capacity. Depending on the panels you buy, you can get quite a bit of power even on not great sun days. Keeping them clean helps a ton. A mobile one you can point to the sun will get you more power than a flat one on the roof. The cheaper panels have gotten better but you’ll definitely get better power output from the higher end panels.

the truck battery isn’t really relevant to the entire setup. What I would do is put a red arc system in the trailer with shore power. This will get you the 3 charging options (shore power, DC from the truck, solar). You can always start with one trailer battery and add more if needed.

 

What’s the exact pull of the exact AC unit you’re using?

Even on the most efficient AC unit, running it 5-8 hours a day is going to call for a much bigger solar system. You may want to get a generator like most peeps with AC.

I know of a few people with AC in their camper can (efficient roof unit) or AC in their cargo conversion (more efficient mini split unit) and even with a ton of solar they pretty much need to plug into shore power or run a genny most of the time.

As stated above, you need to know your exact needs for the unit per hour of run time and then just start multiplying by how much you need it to know how many panels/batteries.

 

A 120V AC unit and a small Honda generator would be cheaper and way easier. It sounds like you need to pay someone to do this or do a lot more research before trying it yourself. You will waste a lot of time and money trying to figure it out, if you don't. If you are serious about dropping $4k on batteries, you can afford to have someone build you a system that will work well.

 

I pretty much have it all figured out now, thanks everyone for all the good points to concider. A generator isn't an option. I can't be loud where I am going to be set up. I've decided to have enough battery storage to power my AC unit, in a small, heavily insulated trailer, for 5 of the 8 hours it needs to stay cool. I'm assuming it doesn't need to be on 100% of the time to reach my target temperature. I can charge to capacity each night when I bring the trailer home. 400 amp hours worth of lithium will accomplish this based on the AC's draw, and I can always add extra batteries if it's not enough. I'm going to start with just that, and see if I realy need to add solar, or just how much. Then after that concider adding altenator power from the truck if that is needed as well. I'm going with lithium because I calculated the battery weight, and the difference is HUGE! I have a 10' X 5' trailer, filled with hundreds of pounds of produce. It's just to much to add 500 pounds worth of lead, especially to the tounge of the trailer where my batteries have to be located. I won't even need a charge controller until, and if I add the solar, though I am likely too, but that investment can come later. I have Redarch on my radar, but concidering Midnite, and Victron as well. I have found that prices very greatly on the lithium batteries. I definitely want one that has charge management built right in, and it seems like most of the bigger ones do. If anyone believes they know the best brand to go with, and why, that might be helpful. Right now I am leaning toward a single Sun Systems, lifepo4 400 amp hour, charge controlled battery for $2,750. It's the best price I have found on 400 amp hours, and relatively light at about 100 pounds. The only down side I see is that it's all in one battery so I can't subtract from the system if it ends up being more than necessary. Anyone have anything good, or bad to say about sun system batteries? Or any flaws in my logic?

 

The logic seems solid to keep it separate from the alternator and keep it as simple as possible. I didn't take into account charging at home for each day. Smart. When I think solar I think independent of the grid but charging each night and then adding some solar as needed to keep it topped off during the day seems like a good plan.

They're more expensive but brands of Lithium batteries meant for being off-grid tend to be better suited to be taken all the way down to little to no charge and back up again over and over. Good luck with the build/venture!

 

I have been following this youtuber for a little while now and like how he tests the systems before he recommends things.
https://www.youtube.com/user/errolprowse

His website with a bunch of walk throughs:
https://www.mobile-solarpower.com/the-minimalist-great-for-small-vans-and-cars.html

I'm not able to find any information on the "Sun Systems" battery, can you link it?