lithium battery source/price thread

[john61ct]

The half-point monitoring on Victron 712-BMV would help automate spotting any major drifting, you get to set the sensitivity.

But it would take three to manage a 48V bank.

[BruceS]

Originally Posted by john61ct

The proper setup to get to 48V is 16S at the topmost level, with a 16S BMS there (if you use one).

If you are paralleling cells to get to a higher Ah capacity than your cells, or for redundancy, each of those 16 3.2V groups would be a set of paralleled cells, which set needs to be broken down to check / test at the individual cell level.

Maybe you should start another thread or ten?
This thread is about "Drop in batteries" isn't it?
Most don't have access to the "16s"?

[ronstory]

BTW, Relion seem to have just changed their pricing, $1050 for a RB100 on their website.

https://relionbattery.com/products/lithium/rb100

[john61ct]

Originally Posted by BruceS

This thread is about "Drop in batteries" isn't it?

Well OP never did clarify iirc, but yes that's what I've inferred so far.

My point is that 12V drop-ins are not generally designed for serial'ing into higher voltages,

and I was explaining why by comparing to the usual way 48V packs are laid out, since interest in that voltage was being discussed.

BTW 16S / 48V is a very common layout, plenty of BMS on the market for those who want to go that way.


And note there are also practical limits for paralleling these 4S / 12V drop-ins if increased capacity is needed try to buy units as large as possible, personally I try to stick to 3P, maybe 4 strings max in a pinch.

[senormechanico]

Originally Posted by john61ct

But you'd have to pretty uninformed to allow your LFP bank to sit for any length of time at any high SoC, even while being actively cycled.

Anyone bringing up storage issues is told 40-50% is the norm, but lower is better, so long as there is no risk of dropping anywhere near say 3Vpc.

Like leaving a BMS attached, a frequent cause of banks getting murdered.

John, John, John.......
If you actually OWNED AND USED LiFePo4 you would have more than theoretical blather to throw around.
I purchased a set of slightly used for tests , four 200 aH HiPower cells from Witzgall, a poster here on CF.
The cells were installed in my boat in (as far as I can remember) 2012.
They have been rarely plugged into a charger, but rely on solar with a finishing charge of 13.8 volts. Winter in the PNW is not solar friendly.
If I DO plug in the boat in the winter, it's just to run a dehumidifier.

They have been run up to 14 volts at times, and have run a 24/7 load of around an amp in that whole time.
They have been discharged down to less than 20 % a couple of times, and have seen temps between 40 and 90 degrees f.
They are the only bank on my boat which runs engine start, watermaker radar, diesel furnace, fridge freezer, local area network etc. and all the usual toys.
For a couple months every summer they are run hard.
I can see NO LOSS of performance or capacity in 7 years.
So, what am I doing wrong to keep from fulfilling your desperate bleatings?

[john61ct]

Sorry, there is no contradiction there.

Of course they can last decades when well treated. But if you're shooting for optimal want every thousand cycles possible, you don't store them Full.

Obviously.

[ronstory]

Poking around a bit more, a local PDX solar company is selling them for $999.

https://www.lightharvestsolar.com/ca...4/10334664.htm

[BruceS]

I worry about the "cylindrical" type because it means many, many connections throughout the battery.
I've had several batteries fail that I use on remote controlled items (boats, planes, drones etc) because of failures of the spot welding connections. (hidden from user)

[KTP]

I wouldn't worry too much about the cylindrical type...most big boy manufacturers are doing it that way now, even Tesla. Trojan even had a video earlier this year or last year that showed the Trillium under construction with a laser spot welding and machine vision inspection of the welds.

I'd worry more about the pouch cells and the cells you are recommended to use straps on to keep their shape.

[john61ct]

the cylindricals swell too

better designs have a varying diameter with a clearly defined "shoulder angle", so when they get blown out enough to show there's a problem you can tell, the angle changes to a smooth curve.

[nebster]

Originally Posted by KTP

Any guestimate on how in balance four of these would stay in a series string? Are we talking having to disassemble the bank and manually charge each one every 5 cycles or is this something that would rarely happen, like once every year or two?

I'd place a sizable bet that IF you're willing and able to configure your charging to keep them below the BMS's balancing threshold, then they will stay in balance for a long, long time.

You would trade off some sliver of capacity in so doing, but you would also gain some decent sliver of longevity, probably.

Put another way, I don't see any reason to assume the cells in these drop-ins are any less stable than the ones we can buy at wholesale at $0.25/Wh FOB China. And numerous folks, including myself, have large series strings with no meaningful, observable imbalance after hundreds of cycles.

[KTP]

On a little side note, the Goal Zero Yeti was actually not a completely horrible deal for a Lithium battery if you don't mind Lithium NMO cells. Much shorter cycle life than a LiFePO4 (maybe 500 to 800 cycles vs 3000 to 5000) but quite a bit lighter. The 3075 watt-hr Yeti including 1500 watt pure sine inverter, MPPT solar charger and two AC chargers is only 67 pounds.

They were on sale last week for $2250, which is $0.73 watt-hr

[jhulmer]

Originally Posted by redneckrob

Amp hours (Ah) are a measure of power delivered over time. That battery can supply 170 amps for 1 hour at 12.8V. You seem to be thinking about amps (as opposed to amp hours) which is an instantaneous amount of power. A 700 CCA battery can deliver 700 amps for a very short period of time to start an engine, nothing in reasonable size could deliver that for an hour to make it a 700Ah battery.
I would humbly suggest that batteries and electricity can be very dangerous things. If one is unclear on the difference between amp hours and amps, it points to dozens or hundreds of other important concepts in the field that one may not only not understand but not even know that they don't know exist, any of which can lead to catastrophic consequences for them, their family and guests, and those who put themselves at risk to rescue them. Sorry to be so blunt, but to an electrical engineer that statement is akin to me showing up for your brain surgery and asking the nurse to "hand me the knife"!

Obviously, we come to the Forum to learn. IMHO, It is then your obligation, as a member of the Forum with the knowledge, to help educate.

[patha]

I just put ReLion Lithium batteries in my boat, about $10 per amp hour of storage is about what they cost. plus 800 install. Then size your battery. I put 7 100 ah batteries in, just to avoid failure of one 200 ah or 500 ah battery as example. Victron charger inverters. I have previous experience with 3 500 ah Mastervolt Lithium batteries put in 2014 in my Lagoon 450 sailboat. the real issue to watch is voltage regulators managing charge from the alternator.

[SailingTSB]

Well Since it is hobby of mine that i love playing with Lipo's here is about 2 cents worth of what I am running.
4 -8D size 195AH at 60Vdc or 28Kwh that I got for about $3500 each.
Now to put that into perspective that would be around 800Ah per battery at 12Vdc for around 3200Ah total for $14000.00
Now that being said these are Leaf Battery's Home made by me with a full multi BMS systems and safety shut downs, but my inverter could not pull or push the kind of power these battery's are capable of storing and releasing. I Have a video Out about the Volt Battery's I did and the newest ones that video is in the works..
Now to Answer the common questions I get


Are they safe? That is all relative to how they are installed and monitored
Safer than the battery's they used in the subs in the 50s

Do they like salt water? Ah no not at all but most things dont...

Can you run your Ac's? Yes all three of them thru my Victron inverter 5000 watt quattro they will all run for about 4hrs or just the main and our hull for 6 and so on.
Were do you get them? I build them and the packs are getting harder to find as more people jump in I have 6 boats now running both Volt and Leaf packs in 48v and 12v.
Here is the link to the volt install video if you care to watch it
https://youtu.be/9GoSDOM-jVI