Flboy - Custom 6x12 Off-Road Toy Hauler Conversion

[featherliteCT1]

I am so glad to hear that you are going to build your own LifePo4 battery system and, especially, that you are going to document your install on this site. I have just begun looking into a LifePo4 system to replace my FLA batteries and love that fact I will be able to learn from what you do.

Best wishes for a smooth and successful build!!!

[foxontherun]

I second that....waiting will be the hard part, ha! Hurry up Don, ha!

[flboy]

Thanks. Waiting is the hard part. I won't get the batteries and BMS until March sometime... but that is also when the trailer should be ready... I ordered windows , Gray Water Tank, Fresh water tank, and a few other things also. Since I am not working now.. I hope to do a marathon build in 30 days or less as opposed to my last build which took 9 months working some on weekends and evening here and there.


I am excited about this battery. I will have $582 in a 280aH (100% useable aH) which is about the same $ per aH for a Lead Acid battery. I sure hope this works... Also... will weigh about 48lbs.. which is also 25% of what my 4 golf car batteries weight. I will just move this battery bank between my two CTC's as needed. Will save about 180lbs of hitch weight on my 7*18Vnose CTC.

[flboy]

Ordered so Far. I will Update and repost as I go which should result in a full list. I am trying to figure out how to draw up build plans on the computer... maybe can get some help? with anyone familiar with the Software packages. I have a pencil sketch I could share... Not sure I want to spend the effort needed for me to draw this up on the PC.

Running Total.JPG (192.75 KiB) Viewed 1804 times

Trailer Upgrades:

[onehoser]

i dropped the ball when i ordered my 6x12, i should have gone with the 24"x72" side door.......hindsight is 20-20

[flboy]

Hindsight is always 20/20. Yes, doors take up valuable wall space in a small camper. Big barn doors in back if I need to get anything larger inside.

Sent from my SM-N970U using Tapatalk

[Rainier70]

Congratulations on your new build. It should be easier to tow and maneuver. I liked our 6X12 for that, but I am sure enjoying our 7x16 now especially when my hubby comes along. I do have to be more careful of where I go off road in the 7X16 though. Google Earth is my best friend for finding areas, but it is still safer to stop somewhere and unhitch the trailer while I explore questionable areas in just the truck. That has saved me from some nasty surprises even in the 6x12.

I had to laugh, I think I ordered the same lithium cells just before I saw that you did too. I am still looking for a BMS though. I need one with a good low temperature cutoff. I really debated on risking buying it as I still have two good golf cart batteries that are in my set up now. They have some good years left in them, but the advantages the Lithium offers swayed me over. I have a lot of self educating to do before they get here! Wishing us both luck on this battery setup!

[flboy]

Cindy, I ordered the "DALY Smart 4S 12V Lifepo4 Lithium Battery Protection Board Balance BMS 150A High Current with Bluetooth APP". It is 150A continuous (1,875W) and costs about $113 from AliExpress. The 150A model is much smaller than the 200A and 250A version, so It will be easier to mount with battery pack. It has Bluetooth so all charge parameters can be monitored and adjusted if desired. According to the specifications is has a Charge Temperature control, but I do not see a thermocouple. It must be on the BMS board and is assumed it will be mounted on the battery pack... not sure if that is ideal, so I will need to watch that. I cannot see ever needing 1,875 watts continuous at any time. My Air Conditioner choice (5000 btu window unit) will only take 450W running and fridge is 60W. After that it is just lighting... maybe a 900W microwave if I decide I need one later.

I am going with only 400W of solar panels due to real estate on the rooftop.. but also, the LifeP04 batteries will charge faster and at full current when sun is available.. unlike the FLA batteries that are very slow after 80% charge regardless of available power..

In any case... a lot of choices out there for the BMS and it can be confusing. I am definitely in a learning mode on these. For me in is not as much about saving the $$ as it is learning new things and building myself. I enjoy that most of all... just like I am going to enjoy doing and documenting this build.

Yes... the 6x12 and maneuverability is what I am going for. My 7*18 is very nice... but terrible in tight places which limits me and causes a lot of stress when I get into tight spots. The 6x12 should help tremendously in that department,

[Rainier70]

Thanks, Don, for the info on the BMS. I too enjoy the learning, designing, and building process. It is all so much more fun when it is do it yourself. I am looking forward to seeing what you do with this build.

[flboy]

I ordered a small adjustable power supply (0_30V and 0-10A ) that also has current limiting so I can do Top Balancing when I receive my new 280aH LiFeP04 cells. I can use the shunt/monitor and inverter that I have for the CTC to run capacity test after I assemble.

I will use the power supply on my workbench anyhow for other projects and etc.. but I wanted to make sure the cells are balanced to start rather than assume the OEM sent me balanced cells and that the BMS will eventually correct..

Sent from my SM-N970U using Tapatalk

[featherliteCT1]

Could you please share the name of the power supply so I can google it or else furnish a link so I can see what you bought?

[flboy]

Could you please share the name of the power supply so I can google it or else furnish a link so I can see what you bought?

This is what I ordered for $54.99 on Amazon. It is on sale at 29% off. Lots of uses for this when working on electronic projects.







https://www.amazon.com/gp/product/B0751 ... UTF8&psc=1

[featherliteCT1]

Thanks. Does "switching" simply mean that the voltage is adjustable within the designated range?

[flboy]

Thanks. Does "switching" simply mean that the voltage is adjustable within the designated range?

No, "Switching" is referring to the type of power supply . It uses a Pulse Width Modulating technology to develop the voltages. They are cheap and efficient. These type power supplies are a little "noisy" from an electrical perspective and can create some RF interference... I wouldn't want to have it on and nearby when using my HF Radio for instance. The other type of power supply is a "Linear" power supply. They are less noisy, but use heavy and expensive transformers in their process.

[featherliteCT1]

Thanks for the education!