Herebus Hell Build

Herebus

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Joined
Dec 29, 2016
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37
The journey starts.

I'm looking at a 48v system, as many of the inverts are sitting in this range, in addition the current draw is less (less loss to heat) for the same wattage compared to low voltages. For commercial system, the DC voltage is much higher for efficiency, however at 100v up it gets dangerous....at 50v you will feel it. I am basing this voltage on 14S52P (14 modules in series, with each module of 52 batteries in parallel) which will give me around 12kwh. 14S rather than 13S seems to be where members are leaning as the preferred build. It is expected for a 12wkh system to have 80% usable power (battery longevity) , so in actual real terms should have ~10kwh true available power. I have decided to go with 5000mah as they are the most cost effect for the price point for new batteries.

I have been buying:
New 186505000mahfrom DHGate ~$1.74AUD a cell.
Batteryholder Module - 13*4 52 holes for 48v 10ah li-ion battery pack from Aliexpress ~$10 a set of 2....would like to get them cheaper.

Need to get:
Copper flat bar 15mm x 3mm x 250mm;battery side bus bar. (130AMP (6Kw peak current at 48v * 130A)per module based on AWG ~ 50 degrees C)
Smaller copper rod bus bar for top of batteries...not sure on the size?
0/2 AWG Lugs and associated hookup wire.
Heat Shrink tubing to colour code bus barends.
0.5 mm tinned copper fuse wire (~35AMP burnout)
Inverter Charger or Hybrid Solar Inverter (5kw), as I have 5kw of solar.
Gas Soldering torch to solder copper bar. A soldering iron will not handle the heat loss of the bars.
14SBattery Management System (BMS)

Need to consider:
Over Temperature (fire) isolation.
Eliminate easily combustible materials around battery pack construction.
Reduce risk of module shorting. Lithium batteries have a very low internal resistance and will happily dump their load in a very short period of time; melting/fusing and generally self destructing.




With luck nailed in 12 months
shocked.png
 
5000 mah ??

You might need to ask seller more questions I think..
 
Herebus said:
New 186505000mahfrom DHGate ~$1.74AUD a cell.

Yup fake capacity, highest capacity available is 3400mAh
Beware some 9000mAh cells actually tested as 900mAh, so actually terrible.
Expect to pay $8-$10 for new high capacity cells, which you aren't going to get from China.
 
Update 2

The 18650 5000mah from DHGate ~$1.74AUD a cell arrived and were tested with the Opus Charger. From the first batch 8 cells were tested , which came out to be around 1200mah. And of those one cell was boarder line..so not even close to the stated 5AH stated in the specifications....we live and learn. I have made it clear to the seller I was not happy and currently going through the dispute process.



So I have changed track, given my remoteness, getting hold of second hand packs of cells is problematic, so I am sourcing 100 cells for review directly from a cell manufacture through Alibaba...not AliExpress (see attached)...cutting out the middle man. So far the process is going OK. I am looking at 2400mah batteries with 2C discharge @ $1.70AUD. I have seen cheaper, but lets see how it goes....need to get a rung on the ladder.
Cheers
 

Attachments

  • GEB18650 3.7V 2400mAh.pdf
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On youtube there's a video of someone doing a test of all those Chinese 18650 batteries:
Seems the best source of good batteries are 3rd party laptop batteries (he even provides a link to the ones he buys).

That might be an option for you if the alibaba doesn't work out?
 
rumey said:
On youtube there's a video of someone doing a test of all those Chinese 18650 batteries:
Seems the best source of good batteries are 3rd party laptop batteries (he even provides a link to the ones he buys).

That might be an option for you if the alibaba doesn't work out?

Thanks for that. I will look into it.

I just purchasednew 850 x 18650 at $1.25 each, with shipping of $250, cost me ~$1335 US.

This was through Alibaba, and in general it was hard work dealing with sales. As I have Zero faith in Chinese sellers....too many times burnt. Seems laws changed at the start of this year in relation to shipping lithium batteries...especially bulk. So shipping is problematic.

Anyway, its a start....~6kwh.
 
frasernator said:
I haven't actually purchased anything from these guys yet but when I'm ready I planned to source fromhttps://liionwholesale.com/

Anyone have experience with them?

No, but what I have found from myjourney there is a heap of battery manufacturers claiming to have particular brands. Its very difficult to determine what is legitimate, fake or just copies.

Given that we cant physically test the batteries before they send them, there has to be trust. 'llI let you know how I go with the mob that I just purchased from, as they are cheaper than liionwholesaler.

I should have the batteries by the first half of March.

Cheers
 
I managed to get a refund on the DH Gate batteries...which is an upside.

Downside the wire I ordered from Aliexpress for the fuse was 0.1mm not 0.2mm as requested.

Here is a shot of the 5kw solar panels that will power the batteries. The other photo is the wiring underneath, using stainless catenary; with plastic inset washers to ensure stainless and aluminium don't touch.

image_juaquc.jpg


image_hpwjso.jpg
 
You might find it works well.. do some tests on it.
 
0.1mm could work. Im using 35AWG that is roughly 0.15mm and that one is said to be 5A and will trip fast at around 8A. 0.2mm depending on what type it is can be as high as 10-15A before it trips fast enough.

As have been said before the max a cell would give out is 3400mAh and the weight should be around 44-46gram. If the cell you buy dont have a known brand always google it. I also did a test on all cells i found on Ebay in end of last year.

if you need new cells nkon.pl could be a source to check out. (No im not affiliated with them)
 
mike said:
How much did that red mounting rack cost? I've looked in to things like that before and the racks end up costing more than the panels themselves.

Cost of the red rack, Idid this myself, brought the RHS steel from BlueScope / OneSteel (Oz), and a MIGwelder (very forgiving)...no idea on the actual cost.Design was based on a calculator using the latitude...I will get shading around 4 weeks a year on the bottom of the cells...but given they are horizontal, bypass diodes should work.....This is an expected loss, as in a low latitude, panel separation in the depth of winterwould have to be much larger. Angle best suited apparently for Spring and Autumn
For the aluminium rack itworks out to be about $50AUD a panel... straights,feet, clamps and earth clip. Cutting was doneusing a wood circular saw...butter.

Wiring is compliant to national wiring laws.

As a warning, DC is a killer, a single string is around 350V, even at dusk. If you need to do any wiring do it at night,as the risk is not worth it.
 
If you haven't actually built any packs yet, you may want to consider this re. 14s over 13s if your primary draw will be an AC Inverter. The 13s will fit you more into the window that the 48V Inverters are designed around. Sure it would work fine at 3.7 volts higher, but the way most inverters are designed such that the over voltage essentially gets thrown away. Yes I'm over simplifying, but even most of the $4000+ inverters don't have a DC-DC converter on the front end. So it just uses what it needs. So in a sense you would be wasting that extra series row of cells that could be put into parallel where you could increase your current storage. Its kinda like if you have 120vAC (in the US anyway) instead of 110vac, most all appliances are designed to run on 105vac or less and don't run any better or more efficiently at higher voltages. But people go with the higher voltages so they can run long extension cords and such. But this shouldn't be a consideration in your DC setup as all your cables will be oversized right?
Just something to consider.
I will be going 14s myself, but that is just so I can do dual purpose as 24v for GP or 48v for inverter. And then I just have a 40 amp DC-DC converter to provide all the old-school 12v stuff in my RV
 
Aspendell said:
If you haven't actually built any packs yet, you may want to consider this re. 14s over 13s if your primary draw will be an AC Inverter. The 13s will fit you more into the window that the 48V Inverters are designed around. Sure it would work fine at 3.7 volts higher, but the way most inverters are designed such that the over voltage essentially gets thrown away. Yes I'm over simplifying, but even most of the $4000+ inverters don't have a DC-DC converter on the front end. So it just uses what it needs. So in a sense you would be wasting that extra series row of cells that could be put into parallel where you could increase your current storage. Its kinda like if you have 120vAC (in the US anyway) instead of 110vac, most all appliances are designed to run on 105vac or less and don't run any better or more efficiently at higher voltages. But people go with the higher voltages so they can run long extension cords and such. But this shouldn't be a consideration in your DC setup as all your cables will be oversized right?
Just something to consider.
I will be going 14s myself, but that is just so I can do dual purpose as 24v for GP or 48v for inverter. And then I just have a 40 amp DC-DC converter to provide all the old-school 12v stuff in my RV

Thanks Aspendell, all good points. My current thinking is going with S14 and utilising the GoodweGW2500-BP. A DC-DC converter sitting between the panels and the Inverter.


Currently waiting for 800 batteries from China, copper bus bars and fuse wire. I have also just purchased the remaining plastic 4x13 cell holders..to make it up to 28 modules of 52 cells.
 
Not down and out.

After purchasing new 18650 from China, Batteries have finally been passed by Customs in Melbourne, and on their way to Tasmania.

This is the first time I have imported anything like this via ship...and to be honest if you have a choice to pay for a door to door service, and it seems expensive, take it, as its three times less than dealing with the freight companies.
 
Great news,

850 Batteries from China have turned up with a mean weight of47g. Arandom sample of 4 are now in the Opus for testing their capacity.

Cheers

image_dgiemo.jpg
 
Herebus said:
Thanks Aspendell, all good points. My current thinking is going with S14 and utilising the GoodweGW2500-BP. A DC-DC converter sitting between the panels and the Inverter.


Currently waiting for 800 batteries from China, copper bus bars and fuse wire. I have also just purchased the remaining plastic 4x13 cell holders..to make it up to 28 modules of 52 cells.



That should work, if your inverter is under 2500watts, your supply voltage for charging the pack is 150-480v DC and you don't mind losing another 5-20% of your power in conversion each way. Also an extra 200 watts a day sitting idle.

I'll be interested to see how that works out. Keep us updated :) :exclamation:

If that unit is solid for you I might consider incorporating one as well.
 
Aspendell said:
Herebus said:
Thanks Aspendell, all good points. My current thinking is going with S14 and utilising the GoodweGW2500-BP. A DC-DC converter sitting between the panels and the Inverter.


Currently waiting for 800 batteries from China, copper bus bars and fuse wire. I have also just purchased the remaining plastic 4x13 cell holders..to make it up to 28 modules of 52 cells.



That should work, if your inverter is under 2500watts, your supply voltage for charging the pack is 150-480v DC and you don't mind losing another 5-20% of your power in conversion each way. Also an extra 200 watts a day sitting idle.

I'll be interested to see how that works out. Keep us updated :) :exclamation:

If that unit is solid for you I might consider incorporating one as well.




Thanks Aspendell, I did not realise the loss, but when you think of it,the batteries are powering both the inverterand battery charger.


The Opus test indicated around 2700mah, and with the weight, looks like I was not screwed.


Cheers







image_htgmzo.jpg
 
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