608AH Lithium Battery Build

[Bryn23]

I don't see a lot of lithium battery builds here as most just buy a pre-made lithium battery as i have done in the past, but as i needed more capacity for longer trips i decided to commit on building a bigger battery.

In November i ordered my Eve 304Ah Cells, which currently have 320Ah capacity from the testing, they finally turned up yesterday after a long wait at the freight forwarder here in Aus.



I ordered from Shenzen Luyuan Technology Co. LTD through Alibaba, The owner is Wan Amy, and is highly recommended in battery building circles, due to the fact they are Real grade A new cells straight from the factory with factory documented testing, another benefit is the packaging, 2 cells to a box fully foam padded, corner protection plates.

You will pay more for these cells, but Alibaba and Aliexpress have a lot of so called new cells, which are not new and of the capacity stated, also the packaging used is not suitable from some of these guys, you don't want old dented bloated cells with QCode's grinded off.

So i ordered 8 x 304Ah cells, as i'll be making 2 x 12v packs to give me redundancy out on the road.

Each pack will have a JBD 200 amp 4S BMS with heater port to manage the cells with Bluetooth support, a bit of an overkill, but these BMS have a huge heatsink and heat is an issue here in Aus.



I decided to use flexible busbars (layered tinned copper strips), as it is being used in a mobile environment and they handle more amps than the stock busbars that i received with the cells

I've currently got the cells clamped together to top balance the cells to 3.65 volts to ensure they are completely charged, as a balanced pack is a more reliable pack.



The only issue is that my two DC chargers are only putting in 5amps each on C.V, so it'll be charging for over a week before i can seperate them and make my packs, although i'll discharge them back down to 30% before doing so.

My wife wasn't happy that i dragged the outdoor table inside to use , but i'd rather charge them here than at the workshop, as due to isolation orders, i don't want these sitting on a charger at the workshop and unable to go out there and turn the charger off.

So, I was planning on building a holder for them out of steel or plywood to go into the existing battery area were my current 240ah lithium battery is sitting, but while i was waiting for my cells, i came across this that someone had 3D printed.



So, of course i decided that i really need to get a 3D printer for the workshop , so hopefully i'll see my Prusa Mk3s+ soon, having said that i'm still designing my own similar version on Fusion 360 as i want to use threaded studs as i use fuse blocks on my batteries and i need to keep the height low.

Now, i do imagine it will take me a while to design it in Fusion 360 as i only just started learning it two weeks ago, so i'm thinking i'll make a plywood enclosure first to test and use, until i can design what i want, and learn to master large 3D prints.

If anyone is interested in the above case to suit these Eve 304ah cells and this 200 amp BMS, i can can send you a link to the creator on GitHub, as he has loaded the STL and Fusion 360 files for open use.

Well thats all for now, i just have to wait for the top balance to be completed

 

[Dellmassive]

Thats awesome . . .

keep updating the thread .

With loads of pics and testing data.
++++++++++++

most pre-built lithium's from Manufactures seem to use the 18650 sytle cells. (very numerous)

some have moved over to pouch cells now. (lighter but more delicate)

and some like the Roamer are using these Calb style cells - Roamer LiFePO4 Gen2 230Ah Seatbase battery -- "How I Done It" --

@RoamerBatteries

This is my 230Ah battery with 4x cells




+++++++++++++

 

[Bryn23]

That under-seat battery is great concept, i noticed that the + and - connections on your battery look like the same 200 amp versions that i'm still waiting for.

These roomers aren't available here, plus i don't have the space to fit them under my seats, but this would be great for new builds that haven't put a sub/amp and diesel heater under there seats.

I've noticed that there are more pouch versions coming out, i personally wouldn't trust pouch cells off-road, those corrugations would most likely cause an early failure.

We have a quite a mix over here in regards, to Prismatic and Cylindrical, i went out of my way to look for a prismatic pre-made model around three and a half years ago, as i felt that the spot welded 18650 cells was a weak spot and it was possibly easier to fix a 4S pack on the road if i needed to.

I have been exploring making a new starter battery later this year out of LTO cylindrical cells in a 6S pack, but i have to see how well I can print ASA filament to make a battery case that will fit those cells.

 

[Dellmassive]

Very good.

For future reference....

@RoamerBatteries do you ship to Australia?

If so what is the additional cost?

 

[Bryn23]

Dell, im not sure it would be worthwhile for Roamer to ship, we have a surplus of suppliers over here with very cheap prices as we have a free trade agreement With china and our shipping prices from there aren’t as much.

To be honest I’m not sure there Is a lot of margin in our market to make it really worthwhile again the cheap oem lithium battery’s

Also campervans and day vans aren’t as popular here like in the UK and Euro, it’s 4X4 and huge caravans where space isn’t that much of an issue.

From what I’m seeing here, is a push towards 48v lithium server batteries, due to high use of air con and inverter use

 

[Dellmassive]

Makes sense.

Looking forward to seeing more of pics of my your build.

 

[RoamerBatteries]

Very good.

For future reference....

@RoamerBatteries do you ship to Australia?

If so what is the additional cost?

We can ship direct from the factory… the issue would be providing warranty support in case of any faults. So it’s not an option yet sadly.

 

[Bryn23]

Well, the cells are now top balanced, only took around 10 days , but they are now balanced and i can discharge them to 50% so i can uncompress them and put them into packs.

I've been working on my own battery case on fusion 360, this has 6 compression rods in each case, i still got a few things to play with, im thinking i'll print the VW badge on the grey case material to match the BMS cover.

Now i just have to wait until my 3D printer arrives, i'm looking at about 2 weeks of print time for the case at this stage

 

[FYPO]

V52 on the design, that’s when you know you’ve put serious time in!

It’s looking good!

 

[Bryn23]

V52 on the design, that’s when you know you’ve put serious time in!

It’s looking good!

Thanks, its been a big learning curve, and yes a lot more time than i thought it would take, but it's almost done, i'm waiting on the stainless screws/fittings to ensure i got the dimensions 100% correct, and insert some locating rings in the case wall.

There is a lot more going inside the box, but i haven't got the skills yet to do all that sectional break up exploded view.

The Filament is ordered, Silver PETG for the case, and Red PETG for the Logo and BMS cover.

i might make up some battery terminal cover caps, once I've printed and assembled these battery cases.

 

[Bryn23]

Well, its been a while since i posted, i had an issue with my 3D model, i wasn't able to adjust some of the Parameters without stuffing up the model, i only needed an extra .3mm width for my cells, but the way i had set up my model i wasn't able to fix it.

So i started again as it was the easiest option, but it didn't take as long, and i had a better understanding of Fusion 360, so i'll take that as a learning experience

I removed the VW logo and add my Edition 79 logo to match my decals i had made, as its 79 Edition



I played around with the slicing software and found an experimental fuzzy skin option, so after around 15 trial blocks, i found a finish i liked, so i got printing, one single case component takes 33hrs, so it took a while






I had to trial the lid in black as i burnt through a fair bit of silver filament through trail and error, there is a 6 week wait on the next shipment of Silver filament i've been using, so i'm prioritising the second case first with the remaining filament.

I found a few design flaws while printing, such as not having enough chamfer for the bolts to sit completely flush, and clearances and slicer profile settings.

I also designed the front panel to be removable, so i can change the fuse if needed.

Im now printing the second case, and working on a better slicing profile for the lid to resolve the over extrusion issue i'm having.

In hindsight, i should have just tig'd up a steel case as i could have had it done in a few days, but this has been a fun experience learning something new.

 

[JOG]

And you got yourself a 3-D printer!!!

 

[Bryn23]

And you got yourself a 3-D printer!!!

Maybe , I’ve had it just under 5 weeks and I’ve already clocked up just over 600hrs running time on it.

I ended up getting a Prusa MKS+, so far it’s been quite reliable

 

[RoamerBatteries]

This is brilliant, I love the design and build quality of that case. We’ve been experimenting with the EVE 304Ah cells and have a layout design for a 600Ah battery with standard ABS case… just mulling over whether there’s a market for a battery that size. If you need any help with yours then please feel free drop me a PM.

 

[JOG]

This is brilliant, I love the design and build quality of that case. We’ve been experimenting with the EVE 304Ah cells and have a layout design for a 600Ah battery with standard ABS case… just mulling over whether there’s a market for a battery that size. If you need any help with yours then please feel free drop me a PM.

Completely agree! There’s a lot of thought and precision going into the project.

 

[Bryn23]

This is brilliant, I love the design and build quality of that case. We’ve been experimenting with the EVE 304Ah cells and have a layout design for a 600Ah battery with standard ABS case… just mulling over whether there’s a market for a battery that size. If you need any help with yours then please feel free drop me a PM.

Thanks for kind words and your offer, it’s been a fun journey and it’s something different to woodworking & steel fabrication. I really should of learnt 3D modelling a long time ago, but I was trained in hand drawings and 2D CAD, and I still make custom designed furniture with 1:1 scale drawings, old habits die hard.

I do think there is a need for 600ah packs in the near future, but I think it’ll be more Popular in the larger vans (Crafter/Sprinter) but having said that, its hard to judge what the market wants & what they are prepared to pay.

 

[Oldrat]

Loving this thread Bryn, I do consider anything electrical to be a kind of black magic

Now a 3D printer, that sounds like something that I could get into

 

[Bryn23]

Loving this thread Bryn, I do consider anything electrical to be a kind of black magic

Now a 3D printer, that sounds like something that I could get into

Thanks Oldrat,

It is magic, just protons and neutrons magic

3D printing is slow, but great for functional parts and trivial fun items, and it doesn't need a lot of space, having one of these when i built my camper would have been handy for making parts for the build

 

[Bryn23]

Well, printing is pretty much done, i ended up with enough silver filament do the lids.

I sorted out the BMS wiring, crimped it and wrapped it to prevent chaffing.

Cleaned the terminals and lugs with solvent and applied some NO-OX_ID between the terminals and lugs before torquing the nuts down to 5nm.

I also used .5mm silicone sheets between the cells and case and wrapped with high temp tape, the case will keep compression on the cells, i've printed some internal spacers to keep it within spec

I've just got to cut and install lugs the internal cables, plug in the BMS and Bluetooth plugs and i'll be ready to bolt up the cases



Now i just have to sort out the battery enclosure space in the van

For those that were interested, from the cell testing, the highest cell capacity was 324.434 Ah, the lowest cell was 321.926 Ah and the internal resistance was 0.16 on all the cells, happy with that

 

[Bryn23]

Well the battery is finished, installed and commissioned, the cells are sitting at .002 of each other in both packs, so the top balance was worth it, so far i haven't seen a runner cell while under charge. everything is doing its job, so i'm happy with that.

I designed some holding mounts to secure the battery and printed them on the 3D printer, they interlock into the battery and hold it down and also fix it to the rear and front of the packs.





I designed some removable panels for more airflow and so i could access the Fuse if i need to replace it, i also printed some black recessed panels to allow the hinges to click back in, as i had a clearance issue, easy solution.



I used the same panels for the top of the battery box, it makes it easier to check the terminals.

Now i just have to change over the yellow zinc screw fittings to the white pan screw fittings once they turn up next week.

Looking forwards to heading back out on a road for a decent trip, now that we are getting some cooler weather