Small 12v 100AH LiFePO4 battery system for use in a camper

dreadlocks

Well-known member
its not tied into the internals, its wired directly up to the PD output.. the idea being get it as close to the source as possible so its accurate and not suffering from voltage drop.
 

RandyP

Adventurer
Thanks. I looked at lucidchart . Looks easy to use. Just wondering what format you downloaded your sketch as to share in this thread. Guess I have a lot to learn. Did you attach it as a file or just paste it into the text box.
RandyP
 

RandyP

Adventurer
ok, thanks. you used the attach file button to attach the transparent PNG to the text message reply ?
RandyP
 

RandyP

Adventurer
…………….
just finished this project

Very nice setup, a little more than I need for getting away from it all in the boondocks. You might want to start a new thread on your LiFePO4 setup. I'm sure you will have many interested in your Battleborn Li battery setup.
RandyP
 

RandyP

Adventurer
affirmative

also updated my diagram

You must have some fuses in the scheme. And are you using the tow vehicle battery/alternator to help recharge the Trailer battery if you move from place to place on an adventure ?

I have my plan formulated for mounting the grape solar panels on the roof, a route for the #4 wires down to the controller, and an aluminum box to mount the system in. More parts coming tomorrow. Not planning to use an inverter at this time.
RandyP
 

dreadlocks

Well-known member
yes I use a couple of these: https://www.amazon.com/gp/product/B0019ZBTV4/ . You can see em both in this pic with the red caps on em. its now moved to the other post on the BP, this is my first wiring setup that didnt shut off the charger when it was full
img_20180801_173959-jpg.466560


One is directly on the battery terminal and has a 200A fuse on it, I have another on the BatteryProtect with 60A fuse in it for my Solar setup and the PD Circuit box has more for DC loads and charger.

the BV712 voltage sensing leads have their own fuses inline w/em too.. they come that way.

It does get a lil charge from alternator, but only like 4A maximum due to the length of the run and the wiring gauge.. after 6h on the road its barely put a dent in it, solar should fix that.. last season it was just generator, but good thing is it dont have to run long and there is zero pressure to get it back to 100% SOC
 
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RandyP

Adventurer
Thanks for the fuse notes. I ordered a few of the fuse holders that go on the battery/device studs a few days ago. One outfit was slow on itemizing a delivery date for the fuses, so I canceled that order and placed another with another provider, they'll be here in two days. I'm using 60a (battery) and 30a (solar) fuses.

Just noticed your battery box and tie down strap in the picture. Funny, I just picked up one of those from a local NAPA today.

I wanted to get two of these battery switches from BlueSea.com:
Battery Terminal Stud Mount Switch
5990
NEW - Available March 2019
https://www.bluesea.com/products/5990/Battery_Terminal_Stud_Mount_Switch
but they are not available until March. Can be bolted to the battery terminal like the fuse holders in your pics.
 
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dreadlocks

Well-known member
I had a sheet of pluck foam from a hard case I got from harbor freight, a layer of that fit perfectly on one end of the battery in the box to take up any side to side motion.. those disconnect terminals are nice, might get one for my riding mower.

I am planning for an inverter down the line (1200VA) because I want to run coffee maker and microwave (kids amirite?) without firing up the genny.. especially the coffee maker as I like to getup way before the kids and enjoy the quiet.. thats why my main fuse is so high.. make sure to order spares, finding those fuses out in the field is not gonna happen.

you got me going over my solar designs, I managed to change a few things and save me some cash.. might be happening sooner than I had expected.. I've got enough roof I'm hoping to scrape enough sunlight that I have more than enough even in the forest.. I'm putting 600W (2x 300W 32v high efficiency commercial panels in a series) up and expecting maybe 150W-300W mostly where I camp without chasing the sun around, but usually I can get a few hours of direct sun a day and by god I'mna take advantage of it.. big reason I went lithium, a single lead battery could not utilize this much solar.. shooting for indefinite runtimes without genny.. hopefully overkill right now but that gives me some headroom for growth if we start getting more electric toys (drones/ebikes/etc).
 
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RandyP

Adventurer
yes I use a couple of these: https://www.amazon.com/gp/product/B0019ZBTV4/ . You can see em both in this pic with the red caps on em. its now moved to the other post on the BP, this is my first wiring setup that didnt shut off the charger when it was full
img_20180801_173959-jpg.466560

I think you are saying that you moved the Li Batt + wire from the BP 'in' terminal to the 'out' terminal and that when the Li Bat + was on the BP 'in' terminal the BP did not isolate the charger when the li batt was fully charged. I would not expect that change in wiring to make the BP fail that function.
The change in BP power wiring must have been concurrent with using the BM712 starter battery voltage input from the shunt B2 point to look at the load/charge voltage on the BP for fully charged voltage state.

Is there any real need to use the BP out term point for the LI batt + power wiring point?
 
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dreadlocks

Well-known member
no, my original wiring had charge supply inputs connected to the hot side of the battery protect.. and the loads on the other side.. this was so when the battery protect disconnects the loads, I could hookup the charge supplies (fused) and get the battery protect to reset automatically..

I didnt have the 'reserve switch' at the time, so if I drained the battery flat and triggered the BP (not something I plan on doing normally, and actually only ever did in testing) I had no way to connect the charger back up.. now I do, so I can over-ride BMV in the field if needed.. the original way I wired it is the traditional way, battery and chargers on hot side, loads on switched side.. but then I used my EE experience and came up with this solution.

Go subscribe to my build thread and when I start doing solar install in a few months I'll post updated photos you'll get notified.. if your interested.
 

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