Battery bank and charger recommendations

[simple]

I'm building out a trailer for camping at out local ski area and am looking for opinions on the battery setup.

I think I'd like around 400ah capacity.
AGM vs Lifepo4 and appropriate charger.

Goals
Supply power for 4 days off grid.
Charge via shore power at home.

Loads are all 12v. No inverter.
2 diesel heaters.
LED lights.
Occasional vent fans.
Dometic or other cooler fridge.
Charging for laptop and other small devices.

This will be a low budget build.

 

[Dave in AZ]

Go here and read, he has premade plans for various mobile levels.

Mobile Solar Power: Made Easy! DIY Off-grid Solar Power!

Building a vehicle mounted solar power system? Let me help.

www.mobile-solarpower.com

You can disregard the solar panels, solar charge controller, and inverter. But his links for parts, batteries, db fuse and switch blocks, are top notch.

You would buy 2 of the 230 Ah batteries, or 4 of the 100, wire in parallel. Buy an AC charger/ charge controller. Buy a battery fuse, rudc from battery to fuse to a dc fuse block. Here you put a fuse and switch for each of your dc loads amd wire them up. Your total coat will be mostly batteries. So 1340$ for 2 x 230 with low temp protection, or $1487 for 4x 100Ah without freeze protection. Then $187 for an AC charger. Dc fuse block and switches and wiring another $150.

 

[simple]

Thanks. That site looks like it covers a lot. I'm pretty familiar with the basics and have done a lot of 12v wiring.

I'll try to narrow the focus of my inquiry.

Given the simplicity of my requirements, those that have used AGM and Lifepo4 which route would you go for this system?

If Lifepo4 what AC charger converter would you use? It seems the focus for battery systems is mainly solar and DC to DC charging.

 

[Alloy]

Now that the price of Lithium has come down that's my first choice. The recharge time and being able to stop charging at any time without harming the battery is worth the cost.

AGM has the worst cost/perfomance. The capacity never matches the mfg. stated capacity.

Lithium needs to be heated. This is best done with an exteral heating source.

Make sure the BMS has low/high temp and voltage cutoffs.

 

[Dave in AZ]

Thanks. That site looks like it covers a lot. I'm pretty familiar with the basics and have done a lot of 12v wiring.

I'll try to narrow the focus of my inquiry.

Given the simplicity of my requirements, those that have used AGM and Lifepo4 which route would you go for this system?

If Lifepo4 what AC charger converter would you use? It seems the focus for battery systems is mainly solar and DC to DC charging.

Definitely go LiFePo4, it is better in all respects. Prices have come waay down. Lasts 10x longer, charges faster, allows full rated charge use instead of 50%, batteries have integrated Battery Management Systems allowing you to tailor your charge profile to give 20x life vs AGM, much faster discharge rates possible also, much lighter, smaller. To top it off, over a 4 or 5 year oeriod they are thus cheaper too!

I have a similar system in my duckboat to what you want. Battery, charge from AC plug shore power when home, run one major load (trolling motor) and a bunch of LEDs (nav lights, headlight, etc), phines and video. I used to use a deep cycle marine battery, 70 lbs!

Now I replaced with that 230Ah 12v, weighs 45lbs and takes up less space. Wired to a small DC fuse block. All my loads including trolling motor are connected with waterproof plugs, so I can disconnect if issues, cheaper than on off too.

Get this 1st battery, 230Ah. It has low temp and high temp charging protection, great price.

LiFePO4 Batteries for Offgrid and Mobile Solar

Are you tired of getting scammed by low quality lithium batteries that claim to last forever but die in a few months. Never let that happen again! Check out my recommendations below. I open every...

www.mobile-solarpower.com

Buy one of these battery chargers.

Battery Chargers

If you wish to charge your battery bank with shore power (the grid), you will need a dedicated battery charger. Some RV's and conversion vans will have this built into the converter box. If you do...

www.mobile-solarpower.com

Done. If you are looking for specific item recommendations, from someone who knows mobile power systems and actually TESTS them, ripping apart to look at wiring and build, and is knowledgeable and trustworthy, you will not find a better person on internet for RV or van or camper battery systems than Will Prowse, whose site that is.

One last economy note. For 400Ah, you are looking at $1540 for batteries and charger. With wires and case and fuses and dc fuse block, I bet you are looking at $1900.
Prices for prebuilt all in one solar generator (jackery, bluetti, EcoFlow) have dropped a lot. I bought a 2000wh system, so 166Ah for $900. It includes the charger, it includes the DC distribution panel to plug fridge, heaters, phines into. It includes an inverter and plugs if you ever want to use ac stuff. It includes a port for dc to dc charging from car while driving. It includes inputs and an mppt solar charger for adding a solar panel later.

For $2000 total you can get an expansion battery also, bring it up to 416 Ah as you desired. Like only $100 more, but all prebuilt and with everything done in compact case, engineered properly, expandable, and includes way more capability with AC inverter and solar already.
My system is the Pecron e2000LFP, and also the e1500LFP at pecron.com.

I was building my own battery setup in truckbed camper too, but the solar gen all predone beat my design and cost easy.

 

[simple]

I was writing this as you posted and didn't see yours so this post might be out of order.

Well that's settled Lithium it is.

Looking at various battery packs they have their own BMS's built in making wiring in parallel and charging the bank a little tricky and is specific battery product dependent.

So far digging around it looks like the more high tech batteries with individual built in BMS's can potentially link wirelessly to a charger so that the system can communicate with itself during charging. (Not a fan of wireless stuff)

Is there a Lifepo4 battery AC converter charger system where the charger can communicate with individual battery BMS's in a bank via patch cables?

Maybe the cheapest and most basic configuration for what I want to do is to go with 2 200ah batteries and put them on a switch that always keeps them separated. When one is low I'll just switch over to the other one and then charge them individually.

 

[simple]

Definitely go LiFePo4, it is better in all respects. Prices have come waay down. Lasts 10x longer, charges faster, allows full rated charge use instead of 50%, batteries have integrated Battery Management Systems allowing you to tailor your charge profile to give 20x life vs AGM, much faster discharge rates possible also, much lighter, smaller. To top it off, over a 4 or 5 year oeriod they are thus cheaper too!

I have a similar system in my duckboat to what you want. Battery, charge from AC plug shore power when home, run one major load (trolling motor) and a bunch of LEDs (nav lights, headlight, etc), phines and video. I used to use a deep cycle marine battery, 70 lbs!

Now I replaced with that 230Ah 12v, weighs 45lbs and takes up less space. Wired to a small DC fuse block. All my loads including trolling motor are connected with waterproof plugs, so I can disconnect if issues, cheaper than on off too.

Get this 1st battery, 230Ah. It has low temp and high temp charging protection, great price.

LiFePO4 Batteries for Offgrid and Mobile Solar

Are you tired of getting scammed by low quality lithium batteries that claim to last forever but die in a few months. Never let that happen again! Check out my recommendations below. I open every...

www.mobile-solarpower.com

Buy one of these battery chargers.

Battery Chargers

If you wish to charge your battery bank with shore power (the grid), you will need a dedicated battery charger. Some RV's and conversion vans will have this built into the converter box. If you do...

www.mobile-solarpower.com

Done. If you are looking for specific item recommendations, from someone who knows mobile power systems and actually TESTS them, ripping apart to look at wiring and build, and is knowledgeable and trustworthy, you will not find a better person on internet for RV or van or camper battery systems than Will Prowse, whose site that is.

One last economy note. For 400Ah, you are looking at $1540 for batteries and charger. With wires and case and fuses and dc fuse block, I bet you are looking at $1900.
Prices for prebuilt all in one solar generator (jackery, bluetti, EcoFlow) have dropped a lot. I bought a 2000wh system, so 166Ah for $900. It includes the charger, it includes the DC distribution panel to plug fridge, heaters, phines into. It includes an inverter and plugs if you ever want to use ac stuff. It includes a port for dc to dc charging from car while driving. It includes inputs and an mppt solar charger for adding a solar panel later.

For $2000 total you can get an expansion battery also, bring it up to 416 Ah as you desired. Like only $100 more, but all prebuilt and with everything done in compact case, engineered properly, expandable, and includes way more capability with AC inverter and solar already.
My system is the Pecron e2000LFP, and also the e1500LFP at pecron.com.

I was building my own battery setup in truckbed camper too, but the solar gen all predone beat my design and cost easy.

Thanks again for taking the time to reply.

In my truck camper, I went the solar generator route a couple years ago. Goal zero 100ah with 100watts of solar and a shore power input. It has worked great and the plug n play nature of it is hard to beat.

 

[Alloy]

Looking at various battery packs they have their own BMS's built in making wiring in parallel and charging the bank a little tricky and is specific battery product dependent.

For a 400Ah bank it's worth looking at inverter/chargers that have 100 amps of charging.

460Ah with Victron connectivity. From what I've been told the heating system does not contact the cells

12V 300Ah V2 Heated Bluetooth LiFePO4 Battery - Epoch Essentials

Shop the 12V 300Ah V2 Heated Bluetooth LiFePO4 Battery by Epoch Essentials. Perfect for deep cycle applications with a built-in Smart Battery Management System (BMS) and 11-year manufacturer warranty. Order now!

www.epochbatteries.com

Maybe the cheapest and most basic configuration for what I want to do is to go with 2 200ah batteries and put them on a switch that always keeps them separated. When one is low I'll just switch over to the other one and then charge them individually.

Keep the batteries connected in parallel. Allot can go wrong if the discharged battery ever got crossed with the charged battery.

 

[simple]

That 300ah battery looks pretty sweet and the RJ 45 connectors are interesting.

Seems like a lot can go wrong with any high density energy storage if mistakes are made. If the switch is break before make it seems like it would be ok.

What scenarios are you thinking of that would be dangerous besides incorrect wiring?

 

[Alloy]

What scenarios are you thinking of that would be dangerous besides incorrect wiring?

You'll be making the system allot more complicated and shutting down/restarting all the equipment for what gain?

 

[simple]

You'll be making the system allot more complicated and shutting down/restarting all the equipment for what gain?

Good point on the settings. I would only have to reset the fridge. I guess I would have to shut down and cycle off the heaters. Hopefully the ones I get won't have digital controllers.

I know a local battery dealer and am hoping to get some test batteries on the cheap. They have about 10 cycles on them. I'm not sure whether their BMS's will cooperate with the charger when wired in parallel. I'll have to find out.

 

[Hnoroian]

Is the trailer already wired or is this in planning stages?

 

[simple]

Is the trailer already wired or is this in planning stages?

Didn't see your post. It's a blank slate. Converting a cargo trailer.

 

[DRP]

I'm building out a trailer for camping at out local ski area and am looking for opinions on the battery setup.

I think I'd like around 400ah capacity.
AGM vs Lifepo4 and appropriate charger.

Goals
Supply power for 4 days off grid.
Charge via shore power at home.

Loads are all 12v. No inverter.
2 diesel heaters.
LED lights.
Occasional vent fans.
Dometic or other cooler fridge.
Charging for laptop and other small devices.

This will be a low budget build.

Low budget?, first do an energy audit. (I would advise this even if high budget) So you don't waste money on something you might not need or even ever use.

You have what you need in your list above. You can only estimate but figure out how long you are going to run each item each day. The energy consumption for each item will be available on line for your items. work in WATTS !!!! This will give you how many Watt hours per day of energy you need to have stored. Now how many days of storage do you need stored?

Now add up how many watt hours per day times how many days you want and this will give you the battery size you need

You need to assume worst case because even though your heaters will not run all summer, they will be there in the winter. your fans in summer will draw less than your heaters in winter.

Do an energy audit and report back with Watt hours per day needs and you will get some more help

 

[drabina]

Don't dismiss solar panels as a way to charge the batteries if you have space on top of the trailer. That of course unless you know your trailer will be parked with no access to sun during the day. I have a small 50Ah LifePO4 battery and just one 100W solar panel on the top of my car. Without the panel, I can run my refrigerator for about 1.5 days (estimated as temps and length of my outings vary) but with solar panel, I can top it off and should be good for a whole weekend or longer.