camelot-forum.co.uk

ClockmanFRA wrote: ↑Wed Dec 08, 2021 8:07 pm Hi Bili,

Yes everything has gone strange. Just found out that ROLLS are now struggling with a 6 month deadline into mainland Europe. What i have heard is that they are struggling with raw materials stocks.

My French friend already has some 2v BATER OPZ's for a 96v system, and wanted something more. How are your BATER's ?

No French so called Rolls stockist actually stock, but they reckon that they now have no idea when new stock from Canada will arrive.

Found a contact in Spain i know, and he has some ROLLS but a bit more higher capacity than he wanted. But at least the Spanish man has some Rolls 4000 series s480 at a good reasonable price. He is now awaiting shipping costs for a pallet from Spain to France.

I think that in these very uncertain times if you find a stockist with the brand that you want and its a bit higher or lower capacity than you want, my advice is to get it quick.

ClockmanFRA wrote: ↑Thu Dec 09, 2021 9:57 am Stinsy,

Batteries Technologies that are presently available, 2021.
No misleading sales or marketing hype.

Posted this reply on a Australian Renewable Energy Forum.
I thought that some of you here might want to really know what is going on.

Hi .......,

I started with AGM.s i mean real AGM's and good manufactures from the US and Spain, as there are some that say they are but just have wet acid inside. Where true AGM's are just damp plate separators.

With true AGM's i was constantly moving them around and matching actual ah ratings as they got old. I had 1200ah at 48v and after 8 years the messing about with them was getting tiring. Eventually all died as they would lose a cell, turned out that the clearance between the cell plates and the main internal bus bars was only 10 mm to 12mm, so when the cell swelled up it shorted itself out.

I just found that AGMS, hard work.

Below is info gathered around the World on Off Grid batteries, that have actuall modern tech batteries. .........

1) Lead acid batteries are forgiving, and generally "die" gracefully.

Unless you accidentally run them dead one time, then they lose capacity and start dying pretty quick.

2) Li batteries are unforgiving. 1 overcharge or 1 deep discharge, and they are toast. Might get a few more cycles out of them before they die, but either condition damages the battery.

Same as lead acid. Many expensive L16s have been run dead by accident. Their 15 year expectancy dropped to 1 or 2 years. That's why I stuck with the 6 volt golf cart batteries. Just in case I screwed up. Been known to happen.

3) LFP / LiFePo / LP4 are the "safer" batteries that tend to just fail, or swell up and stink.

Swell up and fail is a 'true' statement. Most LiFePO4s are made in China. They do not advertise that the battery needs to be caged and compressed. But, when push come to shove, they will admit this. All of their test data on prismatic cells are in a test cage with 12 psi applied the sides of the cell. Without a cage and compression, the cell will swell. The swelling causes internal cell damage and drastically shortens cell life. The cage and compression is a 'pain in the neck'. Once you assemble a bank, you don't move them easily.

4) Some Mfg's include the top and bottom 10% safety margins internal their BMS systems.
Some don't and you have to program that into your loads and chargers. Your Mileage May Vary. Some rate the full capacity, but only deliver 70% of capacity.
Lead acid batteries like 50% -100%, so same protocols will NOT work for each.

Info from a good friend, ………….. “LiFePO4 batteries operate from 2.5 volts to 3.65 volts. Lead acid battery protocols will not work for LIFePO4 batteries. Totally different chemistry. Totally different characteristics. These cells have proven to deliver 100%+ of their rated capacity between these two voltages. My research and experience shows that they have a very flat charge/discharge curve at 3.2 volts over most of there capacity. When you approach the end of discharge, the voltage drops off quickly from 3.2 volts to 2.5 volts. The same on the charge side. The voltage slowly rises from 3.2 volts to 3.4 volts. Then the last 5% of the charge cycle, the voltage rapidly rises to 3.65 volts. If you limit the operating voltage zone of the battery from 3.0 volts to 3.4 volts, you will get 90% of the rated capacity every cycle AND you will avoid the over charging and over discharging associated with early cell death. These are programmed into the LiFePO4 chargers and BMS. The BMS is the safety device to protect the battery and ensure long life. I also program these charge parameters into my solar charger and inverter.
I am still fairly new to LiFePO4 batteries (15 months). I have done a lot of research. So far they are performing well.
I will keep you posted as time goes by. I am not afraid to admit I was wrong, if and when they fail. Keeping my fingers crossed.
Hopes this helps to understand the LiFePO4 prismatic batteries better. Just a note. The cage and compression does not apply to the round cylinder cells. Only the rectangular prismatic cells.”

I trust this helps.

PS A friend wanted ROLLS lead acid for his installation, 6v 4000 series, However ROLLS in Canada reckons it is having real trouble getting materials it needs, and at present there is a 6 month backlog. I got him sorted with a supplier in Spain that actually has what he wants in stock.

I am sorry but my R&D on the PLANTE batteries 550ah 2v cells is still ongoing, and i don't think my latest book on making your own batteries will be ready until late next summer.