So I will be picking up my cells on Wednesday, I also purchased their Apex BMS, which is just a rebranded seplos. 

I was initially going to buy a steel case and modify it from there, but has since decided to get a 3D printer, draw up some modular designs, and this will now be my project. From the mockups it is going to look good. 

Will post my build log here.

Following....please keep us posted

Where did you purchase the cells and BMS - Edit : OK I found the other thread with info

Edited November 14, 20232 yr by Rudolf

I'm interested in the 3D printing. Keep us posted. 

I'd be following this build

So just a small update. Whilst working on a design, and looking for ways to add some compression, as well as rigidness to a 3D print, I stumbled upon 2 already designed projects. 

The first, is an enclosure for a seplos bms: https://www.thingiverse.com/thing:5604549
And the second, an entire battery box, enclosure, both available for the lf304 and 280 https://www.thingiverse.com/thing:5332483
The enclosure seems to be very rugged, since it uses multiple threaded rods to add strength, as well as compression. 

So I will be using a combo of these 2 designs, combine them, and change them up a bit. 

The base for the case will be as follows:

 

What I will be adding, is a place for the breaker, mini "ducting" that will take either a single 120mm or 90mm fan, it will route airflow over the bms, and then over the battery terminals, then blow out the back.

The design is slim enough so that it can be rack mountable.

Any ideas welcome.

Nice design idea. My only advice assemble it close to it's final resting home. That's going to weigh around 100kg complete. I actually tweaked my back moving my battery to it's final home!! Put me in bed for 24hrs!!

Fan - I would design it to be around the BMS more than the cells. I have not seen my cells reach 40°c yet. The BMS runs much warmer than the cells 

Edited November 14, 20232 yr by cp69

How long will that take to print? 

22 minutes ago, Chris_S said:

How long will that take to print? 

Actually a long time, 1 battery support (bottom part) is 12 hours, it's thick.

I will be on holiday from this weekend, so will have these parts get printed whilst I am gone at a printer farm. The quote is R7.5 an hour

What printer were you using ?

Remember you need to use ePLA (Fire retardant) and can't use standard PLA, ABS, PETG, SBS, etc

You also need to compress those batteries, received my batteries from Apex a few weeks ago, going to build a steel chassis, with fans in /out on both sides.

Edited November 22, 20232 yr by jeeva

19 hours ago, jeeva said:

What printer were you using ?

Remember you need to use ePLA (Fire retardant) and can't use standard PLA, ABS, PETG, SBS, etc

You also need to compress those batteries, received my batteries from Apex a few weeks ago, going to build a steel chassis, with fans in /out on both sides.

I am using ePla on a creality ender 3. The first supports would be done on draft with pla only for testing. 

PLA however, should be fine as the melting point is around 170c (ignition 450c), there should be no good reason for the packs to reach this temps, and if it does, it's probably already on fire. From my understanding, the thermal runnaway of lifepo would be enough to even melt aluminum. 

I am looking into fire suppression devices for safety, at this stage I am on the AFO balls. 

 

There will be compression with threaded rods. Will also do push/pull over the busbars, to cool things down.

 

I might eventually go steel case as well if things do not turn out as I want it, time will tell.

Edited November 23, 20232 yr by Pho3niX90

On 2023/11/22 at 11:25 AM, jeeva said:

What printer were you using ?

Remember you need to use ePLA (Fire retardant) and can't use standard PLA, ABS, PETG, SBS, etc

You also need to compress those batteries, received my batteries from Apex a few weeks ago, going to build a steel chassis, with fans in /out on both sides.

@jeeva  Please put some pictures of your progress, I am still looking at going DIY, but not sure if I should just by the complete Apexium diy kit. It was about $250 dollars for just the box and accessories but when I shopped around for 300 amp fuses and battery terminals plus the time to make the box and compression it might not be a bad price. The box and BMS came to $480.

2 minutes ago, Greglsh said:

@jeeva  Please put some pictures of your progress, I am still looking at going DIY, but not sure if I should just by the complete Apexium diy kit. It was about $250 dollars for just the box and accessories but when I shopped around for 300 amp fuses and battery terminals plus the time to make the box and compression it might not be a bad price. The box and BMS came to $480.

I was charged around 700$ (R13000) for the apexium box.

I have to say, the seplos/apex bms has the cells within 3mv balanced. I was actually planning on getting a v3, but the v2 seems to be doing what it should.

15 minutes ago, Pho3niX90 said:

I was charged around 700$ (R13000) for the apexium box.

I have to say, the seplos/apex bms has the cells within 3mv balanced. I was actually planning on getting a v3, but the v2 seems to be doing what it should.

How's your diy battery pack performing? I've been very happy with mine even during discharge the cell difference is always 3-6mv. Very impressive 

13 hours ago, cp69 said:

How's your diy battery pack performing? I've been very happy with mine even during discharge the cell difference is always 3-6mv. Very impressive 

I have been seeing the same. Before first charge the variance was around 10mv, but after around 2-3mv. I am going to do a seplos HA integration to better monitor the variance, and to pull the cycle counts and predictions with these load sheddings we are seeing. 

14 hours ago, Greglsh said:

@jeeva  Please put some pictures of your progress, I am still looking at going DIY, but not sure if I should just by the complete Apexium diy kit. It was about $250 dollars for just the box and accessories but when I shopped around for 300 amp fuses and battery terminals plus the time to make the box and compression it might not be a bad price. The box and BMS came to $480.

The BMS is overpriced with Apexium, importing might be cheaper. Maybe speak to @cp69 as he imported the v3 cheaper than what apexium charges. If I were to do this again, I would do this.

The DIY box also is overpriced for what you are getting, the majority of the cost probably lies in the PCB balancing, which is just unnecessary for something you will never see.

The cells come with busbars, so no need to pucharse them. 

Terminals are around R150 on takealot, megafuse of around 225a is R180, double up in these 2 items if you really need more (if your inverter is 10K+)

Edited November 24, 20232 yr by Pho3niX90

Thanks @Pho3niX90 I will ask @cp69 about the BMS. I wanted to ask if anybody had done an FNB Swift payment to Apexium as I don't know what to put in for the routing/sort code , is this the swift number? I am just busy adding a beneficiary to maybe buy the cells now and see what cp69 says about the BMS.

2 hours ago, Pho3niX90 said:

I have been seeing the same. Before first charge the variance was around 10mv, but after around 2-3mv. I am going to do a seplos HA integration to better monitor the variance, and to pull the cycle counts and predictions with these load sheddings we are seeing. 

Brilliant let me know when have the seplos integrated. I would love that info as well 

2 minutes ago, Greglsh said:

Thanks @Pho3niX90 I will ask @cp69 about the BMS. I wanted to ask if anybody had done an FNB Swift payment to Apexium as I don't know what to put in for the routing/sort code , is this the swift number? I am just busy adding a beneficiary to maybe buy the cells now and see what cp69 says about the BMS.

@Greglsh yeah no problem you can get in touch with me. I import from China and Taiwan every month so I can add one in a shipment for you 

8 minutes ago, Greglsh said:

Thanks @Pho3niX90 I will ask @cp69 about the BMS. I wanted to ask if anybody had done an FNB Swift payment to Apexium as I don't know what to put in for the routing/sort code , is this the swift number? I am just busy adding a beneficiary to maybe buy the cells now and see what cp69 says about the BMS.

The routing code, also known as the bank code, for Standard Chartered Bank in Hong Kong is 003.

7 minutes ago, cp69 said:

@Greglsh yeah no problem you can get in touch with me. I import from China and Taiwan every month so I can add one in a shipment for you 

Hi @cp69, do you run the Seplos V3 are you happy with it any issues? What inverter are you using it with I have the SunSynk 5Kw. PM me with the costs if you know them of the Seplos BMS please.

On 2023/11/23 at 6:45 AM, Pho3niX90 said:

I am using ePla on a creality ender 3. The first supports would be done on draft with pla only for testing. 

PLA however, should be fine as the melting point is around 170c (ignition 450c), there should be no good reason for the packs to reach this temps, and if it does, it's probably already on fire. From my understanding, the thermal runnaway of lifepo would be enough to even melt aluminum. 

I am looking into fire suppression devices for safety, at this stage I am on the AFO balls. 

 

There will be compression with threaded rods. Will also do push/pull over the busbars, to cool things down.

 

I might eventually go steel case as well if things do not turn out as I want it, time will tell.

I wasn't talking about melting points, I was talking about flammability. Standard PLA is highly flammable, hence you don't use it with anything electricity wise.

2 hours ago, jeeva said:

I wasn't talking about melting points, I was talking about flammability. Standard PLA is highly flammable, hence you don't use it with anything electricity wise.

From what I recall, the ignition point is around 380-450c, but temps above 230c are both discouraged for epla and pla. 

Their "high flammability" comes from when introducing it to an open flame, and the only time that would ever happen, is if the place was on fire, or a battery had thermal runaway. The latter being more worrysome than pla metling away. 

That's just my thinking

The idea is to have a fire suppression device, and maybe eventually I will go the route of steel casing. 

Here are some interesting info regarding plastics and electronics:

• PLA (Polylactic Acid): PLA is derived from natural sources and is generally less flammable than some traditional plastics. It has a lower risk of catching fire, but like any material, it can burn under certain conditions.
• Polyester (PET/PBT): Polyester is known to be flammable, and it can burn when exposed to an open flame.
• Polycarbonate (PC): Polycarbonate is flammable and can ignite when exposed to a flame or high heat.
• Nylon (Polyamide): Nylon is relatively more resistant to burning compared to some other plastics, but it can still catch fire.
• ABS (Acrylonitrile Butadiene Styrene): ABS is flammable and can burn under the right conditions.

The last 4 are typically used in circuit breakers.