How is the best way to build a 12-15kw battery bank

[Vanytoy]

Hi,
I'm from Belgium and i'm going to build an expedition truck in a 24V system. I need in total 12-15 Kw in battery capacity inside that truck.
I will also use around 3000w of solar panels on the roof. For the daily electricity i want to use a inverter of max. 5000W. (210A)
This truck will drive in Siberia and other crazy country's and also Off Road.
For safety i need always (backup) energy for in this sometimes deathly environment, and this for a minimum for 5 to 10 days.

First question:
I think i want to use prismatic LiFePo4 cells.
But i have read somewhere that it is better not to use too large cells (max 200A) in conditions with a lot of vibrations and shocks. This would affect the battery life or even damage them.
What is your idea of this? Maybe someone of you here has more information or has a graph of whether or not this is the case?
But with smaller cells you have more connections! So also more chance to have a damage or bad connections i think?

It is crazy but all what i build must be useful for more things in one, and 100% reliable and also possible to rebuild in a emergency crisis so there is always power. Because no electricity is also no diesel heating!!

Second question:
Can i use two or more BMS's in serie or in Parallel? Or are this special types of BMS's?
Maybe is there a another (better) way to management the battery's?

Last question:
Is it better to build for example 6x 12v battery's and use this to make a 24v battery? And use 3 or 6 BMS's?
Or, for example, if i use the 100Ah cells,
Is it better to, connect 3 cells in parallel (300Ah), and then connect these blocks in series 8 times to get a 24V battery?
And do this double for the total of energy i need and i can use also 2 bms's?

I know it is all crazy but stuck in -58 degrees F and a 50 mph wind is this also!))

All information or ideas are welcome!
I read a lot here on the forum and i find very interesting things here!

Thanks,
Yvan.

 

[Dzl]

For your application, I think you would really benefit from reading the Nordkyn Design series in my signature. The Authors design model shares a lot in common with yours.

 

[Vanytoy]

For your application, I think you would really benefit from reading the Nordkyn Design series in my signature. The Authors design model shares a lot in common with yours.

Hi,

Thanks! I have already read this very interesting information. Yes it is very good and detailed! But i want to double check if it is all true on that website.
Because it is all a lot of money.

Yes, behind the truck is also a 36.000pound trailer with a small 4x4 (older gasoline type convert to electric) inside, and other stuff and fun toys for adults. The trailer is already isolated and heated, so now he must also be electrified with solar panels and a small battery bank. And if we connect this in parallel with the prismatic cells from the 4x4 we have more capacity. So more than nough to prevent all for freezing inside the trailer and able to charge also the 4x4 with the solar panels.
So the trailer is also always capable to survive 5-10 days solo. And if we use a 3000w inverter here we can combine this with the truck and have 6-8kw in total.

So if someone has ideas or suggestions about my project you can always write me! Even negative things. Information is knowledge en i can always choose what i do with this.

Thanks!!
Yvan.

 

[Dzl]

First question:
I think i want to use prismatic LiFePo4 cells.
But i have read somewhere that it is better not to use too large cells (max 200A) in conditions with a lot of vibrations and shocks. This would affect the battery life or even damage them.
What is your idea of this? Maybe someone of you here has more information or has a graph of whether or not this is the case?
But with smaller cells you have more connections! So also more chance to have a damage or bad connections i think?

The information I've seen that suggests using small cells is better for high shock/vibration mostly comes from Nordkyn and his sources. I think you will find that there are not a lot of people on this site who are designing or concerned with harsh applications like yours and can be a little dismissive of these kinds of concerns.

Unfortunately I think there just isn't a whole lot of information out there beyond a few reported failures of 400Ah+ cells in boats, and the information from Nordkyn and Sinopoly. Choosing smaller cells is probably the safer choice until more data becomes available though. And choosing plastic body cells from CALB, Sinopoly, or Winston is probably a good idea as well. And I think one advantage of Winston is they can handle like 5 or 10 degrees lower temperature.

It is crazy but all what i build must be useful for more things in one, and 100% reliable and also possible to rebuild in a emergency crisis so there is always power. Because no electricity is also no diesel heating!!

Yeah this makes perfect sense. I assume you would want high (1) reliability (2) redundance (3) modularity

Second question:
Can i use two or more BMS's in serie or in Parallel? Or are this special types of BMS's?
Maybe is there a another (better) way to management the battery's?

What you can do is arrange your cells in series first (packs of 8) and then put those packs in parallel.

Last question:
Is it better to build for example 6x 12v battery's and use this to make a 24v battery? And use 3 or 6 BMS's?
Or, for example, if i use the 100Ah cells,
Is it better to, connect 3 cells in parallel (300Ah), and then connect these blocks in series 8 times to get a 24V battery?

For the sake of example, lets imagine you are using Winston 160Ah cells. 32 Cells would give you 16kW of capacity. If you arranged these cells into 4 x 8S packs, each with its own BMS, you would achieve your capacity goal, you would achieve individual cell monitoring, and you would achieve redudundance/fault tolerance/field rebuildability, because essentially you would have 4 separate 24V 'batteries' in parallel. If one cell or one pack had an issue, it could be disconnected and you would still have 3/4 capacity.

There may be better ways to configure this with high end BMS, or distributed/decentralized battery management systems, this is probably worth further research.

 

[John Frum]

I know it is all crazy but stuck in -58 degrees F and a 50 mph wind is this also!))

FYI
Lifepo4 batteries
Operating thermal ambient
charging 0°C ~ 45°C
discharging ‐20°C ~ 55°C

https://files.ev-power.eu/inc/_doc/attach/StoItem/3443/190124_CALB_100AHA_2.pdf

0c = 32f
-20c = -4f

 

[Vanytoy]

Hello!
This is so super! I had never expected that other people want to help thinking around my project!
I was very sceptical in the beginning. I have never visit forums and i thought, you must be members for long time befor people want to help you!
But thanks guys for all the information!!

Yvan.

 

[Dzl]

Forums aren't perfect but in some ways they represent what the internet could/should be. People sharing information freely, giving and getting help, community, all without monetary incentive for the most part!

Another forum that you may want to check out is expeditionportal.com, its a forum for overland, expedition, and offroad vehicles and campers.

 

[Vanytoy]

Forums aren't perfect but in some ways they represent what the internet could/should be. People sharing information freely, giving and getting help, community, all without monetary incentive for the most part!

Another forum that you may want to check out is expeditionportal.com, its a forum for overland, expedition, and offroad vehicles and campers.

Yes it is true!)) and yes again, expeditionportal.com is interesting and i visit some times, but we are little different. For example if they stuck in the mud almost all other 4x4 vehicles can help, if i am stuck in the mud, i need a tank! And in Russia also vodka to puy!))

 

[vtx1029]

Sounds like you have fun there. I like to winter camp as well (ice fishing mainly) so I can slightly understand the environment you will be in. The route I would go would be 4 packs of 8cells in series and then connect the 4 BMS's in parallel. I would tightly pack each battery pack and then put them in a container that was foam or rubber lined to help with shock absorption. Keep the batteries in the heated part of your truck or insulate the batteries and use some form of heater to keep them above 10*C.

Good luck with your project and be sure to share pictures when completed.