There are some links in this thread on very useful information on lithium.

https://thegreynomads.activeboard.com/t67732755/lithium-batteries-charging-discharging-balancing/

C0.3 is a battery build to a price. In other words an unsuitable standard.

 Hi peatop,

Some info for you.

download.spark (activeboard.com)

Hi Lilli

I believe you will find that those "bargains" are all in the USA and indeed are hard now to find since they became publicised. It is hard to ship lithiums and by the time you get them here they may not be a bargain. 

There is no market that I know of in Australia for selling these style of batteries and other people who are lithium interested snap any up if they become available. But good luck if you can do it.Then the BMS is the next challenge.

Jaahn

Mike Harding wrote:

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kesa32 wrote:

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lm guessing you got these through Amy ? What's the estimated transport time these days ?

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Amy's company and contact details would be appreciated.

Maybe we should think about a bulk purchase?

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 Yes I did get these from Amy Wan but it seems there are several Amy's that provide batteries in China lol the estimated delivery was set at 50 days from order date and they are coming via sea.

YW-3.2V-280AH, YW-3.2V-280AH direct from Shenzhen Luyuan Technology Co., Ltd in CN This is the company but this is not a recommendation as I'm yet to get the batteries and test them, however this was one of several recommended at the time I ordered and suggest if your interested to do your homework first. one of the issues with bulk buying is import duties imposed on purchases over $1000 (I think) although this doesn't amount to much per cell it's still an added cost, then there are transport issues to other areas once landed here in Aus, when you order and pay it's in USD so you also have to pay for exchange and the exchange rate. But hey for a truly A1 battery it's sure much cheaper than the batteries available to us now. And if one cell fails it's easier to repair than anything you can buy here.

The forum I mostly used was DIY Solar Power Forum I think I followed the link from here, as for which tread I read, well there were many about all aspects of building, maintaining and parts best used to build a decent battery. youtube was another story but I did watch the whole series on Off-Grid Garage - YouTube as this was somewhat close to my heart (done the same thing back in the 90's but lead acid). and many more on different builds, tear downs, testing and charging.

My original setup is an AGM 120ah battery and about 570w of solar power using a solenoid B2B charger and was going to change this to an LFP setup as I went, just because of the cost of the batteries, but decided I needed a better performing battery setup or far more AGM's to get started, the other costs in the change are a decent solar controller and a newer dc to dc charger able to charge LFP batteries. The controller I decided on will be a Victron smart 100/50 and the dc to dc charger which arrived yesterday is a Renogy 20a which was only $109 delivered.

All in all I think this should keep me out of power troubles for now and if needed I can always add more panels.

I considered some of the larger sized cells but thought about the space needed to store them and weight, with the AGM I was just going to have them over the axle but since LFP don't have weight issues it's more about the space, so to get better usage of my space it the trailer I thought the 105ah would be better to manage. There was also talk on batteries under 200ah for mobile systems as this would be less stress on the cells, not sure about this and wasn't really part of my consideration.

The clamping, this is an issue that came under much discussion recently, some of the debate discussed was that it was recommended at high C cycling rates, as this is where the cells would heat up causing the deformation, I'm yet to find a definitive answer to the reasons behind it, however if you read through the manufacturers technical notes they say that with compression you will get far more life from a cell, and now it's recommended. But again they don't specify any reason for doing so.

I guess only the development Engineers would really know why and when we should compress the bank. on the other side of the coin, how is the DIY builder meant to get the bank compressed to the correct recommendations without having the specific equipment to do so? If you were building huge banks say for a house then yes you might consider it, but as this doesn't seem to have much impact on smaller systems with low level charge/discharge rates I don't know that it is worth worrying about.

The thread sizes of different cells over the last few years has had lots of discussion on the forums as well, My guess it has something to do with the tpi and not the size of the screw/bolt/stud given that the torque measurement given is not really very tight, however the 6mm depth doesn't seem to be very much, If I find the supplied screws to be to short I will be purchasing studs to replace them.

Yeah there's pros and cons to everything, l decided to lightly compress mine with wafer thin foam between them to help isolate the cells from each other as the blue plastic wrap is the only other thing .

Also you don't want the studs getting stressed by movement of any kind , it could cause an electrical nightmare very quickly 

Obviously this all counteracts cooling , but I'll be running low c rates most of the time so it'll be ok
I ran studs so l could hold the tension on them with an Allen key while doing up the nuts and touch wood it's been ok , it just doesn't inspire confidence hanging off 6mm x 6mm thread area lol , that's why l recommend the laser welded studs if possible, even then you'd have to be careful not to strip the thread with too much enthusiasm

Hi Peatop,

Have they given you a tracking number to see how they are going.  I also purchased 4 cells but 285ah and they cleared customs on 3 September.  There has been no movement on the tracking since that date.  I'm now chasing up the supplier as they told me two weeks ago it would be two weeks for delivery and today I was told the same thing.

Tim

Good to see you got your batteries, I've had a couple of parcels returned to sender in USA, even with the most expensive air freight. I still want the goods. Looks like next year!

Anyway, I did get a new phone from overseas. One thing I noticed setting up the phone, it asked for maintaining a long battery life, to set the limit of charge to 90% or 80%, so I've set it at 80%.

Whenarewethere wrote:

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Good to see you got your batteries, I've had a couple of parcels returned to sender in USA, even with the most expensive air freight. I still want the goods. Looks like next year!

 

Anyway, I did get a new phone from overseas. One thing I noticed setting up the phone, it asked for maintaining a long battery life, to set the limit of charge to 90% or 80%, so I've set it at 80%.

 

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 Ha ha that's interesting that it's specified by a phone company but I wonder what type of battery it is and how it's charged Lifepo4 is hard to get an idea on it's charge without using a power meter, can you setup the charge/discharge cycle using one? not sure even the victron can do it, not that I'm going to buy one lol

Kesa32, yeah they do look the part and so small, I bought the smallest battery box and I could easy fit 8 cells and double the amps, which I haven't discounted yet but I'm still thinking 300 amps total and would prefer they be 3 individual batteries but put in parallel just so I can have one in the car when leaving the camper out bush while fishing or shopping, I will keep this thread updated on whichever way I go but so for so good, the battery is charged and balancing atm and still waiting on the power supply before running capacity tests and final assembly. as a final note though I am tempted to order more right now lol but I'm saving for my fishing trips atm so no spare cash yet

I ordered my victron 100/50 Friday and it arrived today surprise surprise but still waiting on my battery charger and power supply  but auspost have them so they could be months away yet lol although the very slow snail mail app does say this week.