diy solar

diy solar

280ah Lifepo4 Leisure Battery - Build Thread

I am in about the same stage as you with my battery order. I placed my Alibaba order April 20 and I am eagerly awaiting their arrival.
How much did you spend on 4 280Ah cells?
I may have the same electronic load and BMS. They too are enroute from AliExpress. See attached images.
One advantage I have is that I have spent my career working with electronics. Specifically in the test world. While I plan to use the electronic load to draw current, I have some pretty nice instruments to monitor my charge and discharge curves to prove out the cells and then the system.
I'm on board with most of how you have your system designed and the suggestions offered. The members here are usually very good at providing guidance.
I will be sure to chime in when my hardware begins to arrive.
Screenshot_20200526-135812_AliExpress.jpgScreenshot_20200526-135644_AliExpress.jpg
 
New-bee here... I have a couple questions.

Are you planning to use an inverter? If so, what size?

If I'm looking to do something similar in my travel trailer, then I wont need the Orion-Tr Smart DC-DC charger will I? It looks like you are using it to charge up the engine start batteries for you coach, correct?
 
Mrdanielmh said:
Hey @Haugen !

It looks like we are at the stage! Im still waiting for my batteries but i hsve received my bms! Excited to hear about your build
Click to expand...
We have a mini camper. It's an Intech Flyer Pursue. Really, just a comfortable bed in an air conditioned, off-road ready box. They are really well made, so the investment in batteries to camp off grid for a while is worth it. I would rather keep the camper in the shade, so I plan to use portable solar panels and plug them into the pre-wired port. This will extend trips into the wild.
The backbone of my test setup will be my Agilent 34970A datalogger. I will be able to monitor voltage, current and several temperatures simultaneously and log the measurements every second if I desire.
When the test is done, I can export the data and plot it out to see what my performance looks like.
 
BeerBrewer said:
New-bee here... I have a couple questions.

Are you planning to use an inverter? If so, what size?

If I'm looking to do something similar in my travel trailer, then I wont need the Orion-Tr Smart DC-DC charger will I? It looks like you are using it to charge up the engine start batteries for you coach, correct?
Click to expand...
I might use a small inverter, but I go camping to commune with nature.
There is a TV and radio in the camper for rainy days or when we are on shore power.
The batteries are for when I take it hunting or off grid camping. Not a lot of electricity used except for running the fridge and keeping the phone charged.
 
@BeerBrewer - i haven't decided on an inverter yet as most things i can do from 12v. Im ising the Orion tp charge my leisure batteries from my van starter battery while driving.

@Haugen - sounds awesome! It sounds like you have some good equipment available!
 
Daledevon said:
Has anybody come up with a good case solution for these yet?
Click to expand...

www.hulkenbergshop.nl

Stapelbak met deksel - 400 x 300 x H 250 mm (gladde bodem) - grijs - Transoplastshop

Geheel gesloten grijze stapelbak met deksel. met gladde bodem en gesloten handgrepen. Kunststof dekselbak 400 x 300 x H250 mm met scharnierdeksel en twee snap-schuifsluitingen.
www.hulkenbergshop.nl www.hulkenbergshop.nl

Shipping is around 11 euros if you’re in mainland Europe but you can also find them locally across Europe. Try their chat function on the site if you need a shipping quote, they reply fast.

Otherwise these things are called eurobox shipping containers and they’re the standard here. They’d probably fit 8 of the cells inside as they’re a bit long on the length side But I figure with the bms and some insulation you can make them work.

The problem with every other battery box I’ve researched is that they’re not tall enough for these.
 
mrdavvv said:
I guess the little black things in the positive output of the battery are fuses?, if so.. why not put only 1 to the main line?. Also this main line should be conected to the battery protect, so it can disconect all the loads if necesary.
Click to expand...

Mrdanielmh said:
I thought it made sense to fuse everything seperately so that if 1 fuse blew I still have other charging capabilities.

I thought the Victron Battery Protect was for load, so I only had it attached to the fuse box load so that it would shutdown access to appliance if the voltage of the battery was too low.
Click to expand...

I haven't read through the whole thread so you've probably worked all this out but just in case.
  1. @Mrdanielmh is correctly using the battery protect, it cannot be used the way @mrdavvv describes because (A) its not bidirectional and (B) it cannot be used directly inline with an inverter
  2. You are also on the right track regarding fuses, every time you step down to a smaller wire size, you need a fuse to protect that wire, so unless all your wiring is the same gauge as your main battery cable, you are doing it right. But you may also want a main battery fuse (MRBF or class T ideally)
And then I have an open ended question/thought, IDK what the best practice is or should be for protecting the multiple smaller wires going to and from the BMS. If one or more of those wires shorts or opens (and there are 6 individual pieces of wire and 12 total connections), it seems there is at least a theoretical risk of a situation where too much current is forced through one or more of the wires, and no fuse is sized properly to protect the smaller gauge wire attached to the BMS. How are others with similar BMS' dealing with this? Is this a tempest in a teapot or something to take seriously? Seems as a best practice a fuse on each of the 10AWG wires would be the way to go, but maybe I'm overthinking it.
 
Dzl said:
I haven't read through the whole thread so you've probably worked all this out but just in case.
  1. @Mrdanielmh is correctly using the battery protect, it cannot be used the way @mrdavvv describes because (A) its not bidirectional and (B) it cannot be used directly inline with an inverter
  2. You are also on the right track regarding fuses, every time you step down to a smaller wire size, you need a fuse to protect that wire, so unless all your wiring is the same gauge as your main battery cable, you are doing it right. But you may also want a main battery fuse (MRBF or class T ideally)
And then I have an open ended question/thought, IDK what the best practice is or should be for protecting the multiple smaller wires going to and from the BMS. If one or more of those wires shorts or opens (and there are 6 individual pieces of wire and 12 total connections), it seems there is at least a theoretical risk of a situation where too much current is forced through one or more of the wires, and no fuse is sized properly to protect the smaller gauge wire attached to the BMS. How are others with similar BMS' dealing with this? Is this a tempest in a teapot or something to take seriously? Seems as a best practice a fuse on each of the 10AWG wires would be the way to go, but maybe I'm overthinking it.
Click to expand...
It seems that you may have missed the updated diagram on page 2 where these were removed. The wires you referenced are part of the BMS. They are soldered on the PWB and would probably all receive a ring terminal and be put on the same post. They could conceivably be crimped into a single terminal. Not much chance of single wire failure seeing as though they are only about 8" long.
 
Haugen said:
It seems that you may have missed the updated diagram on page 2 where these were removed.
Click to expand...

Oops yeah, I saw the updated diagram on page 1, not the one on page 2, looks like OP moved away from individual cells, and went with Valence. Points 1 and 2 still apply (and look to still be correct in that diagram).

The wires you referenced are part of the BMS. They are soldered on the PWB and would probably all receive a ring terminal and be put on the same post. They could conceivably be crimped into a single terminal. Not much chance of single wire failure seeing as though they are only about 8" long.
Click to expand...
Yeah the chance of a problem is probably pretty low, but still, I think, possible and unprotected. There are 12 potential points of failure (6 solders, 6 crimps, and if the wires are about 8" 6x8" is 4 feet of wire).
 
You must log in or register to reply here.

Similar threads

D
Fogstar Leisure Battery (UK) 280AH vs 300AH
Replies
2
Views
1K
Frugalone
Frugalone
M
Buy now or wait? 48v battery build
2
Replies
25
Views
1K
mjgillen
M
V
Finished my 12v 304ah battery build with heating
Replies
1
Views
166
Partimewages
Partimewages
Mattb4
My first LiFePO4 build to achieve a cheap 105ah 24vDC.
Replies
16
Views
837
Mattb4
Mattb4
B
Lithium battery build questions
Replies
14
Views
951
DIYrich
D
Back
Top