Lithium mini batteries

[rabbi]

Originally Posted by Letterkenny

These are all 100ah and higher discharge I believe. I’m not worried about not having a Bluetooth BMS - not even sure what the benefit is to be honest, and having multiple helps if there is an issue in one.

If you 100% trust the manufacturer and the technology in this blackbox then the lack of bluetooth is no problem.
If you don't, how do you get critical information such as cell level voltages, cell temps, cut-off voltages, cycles, capacity, ...

[s/v Jedi]

Originally Posted by carstenb

I just installed 6 of these. LiTimes warranties a minimum of 4000 cycles. At 1 cycle per day that means 10 years.

10 years is more than enough for me

They state somewhere that you can connect four in series, four in parallel… I’m thinking why the limitation for parallel? Series is because of the maximum voltage rating of the MOSFETs of the BMS…

[Letterkenny]

Originally Posted by rabbi

If you 100% trust the manufacturer and the technology in this blackbox then the lack of bluetooth is no problem.
If you don't, how do you get critical information such as cell level voltages, cell temps, cut-off voltages, cycles, capacity, ...

It’s a stable battery chemistry and highly rated. I’d be concerned that if you were able to track these items that if something was out of whack, you would probably have Bluetooth not work.

Sort of off topic but I’m personally not a fan of the overpriced batteries out there from battleborn, Dakota, relion, victron, etc. Essentially the same product but at a fraction of the price. I’m assuming they are trying to sell lower volume at a higher price point but that won’t last forever for something that’s just a commodity.

[shimari]

Originally Posted by shrspeedblade

I saw a tear down of one of these, I don't remember if it was Will Prowse or Sailing Temptress on YouTube (both very informative). It was a pouch cell, LiFe chemistry but a bit different, probably not as durable as prismatic cells. I'd go this route if space was the absolute critical factor, but prismatic or cylindrical otherwise.

I believe Battleborn and some of the other top brands use cylindrical.

https://www.youtube.com/watch?v=66lHr-DFNIE&t=337s

Doesn't discuss the cell type, but informative none the less.

[himnher]

Originally Posted by Montanan

Attachment 286342The configuration of your 12 volt batteries in parallel will work properly and is atypical but an enhanced balance of the current of the battery bank can be configured

Interested in the 'better balance' and 'why'. Specifically, if the 'better' hook-up is working becasue of batteries being fewer hops from the live/ground, why not simply direct connect each, and why arrange one battery on a two-hop? Why not each of 'the other three' being a direct connection to the 'principal' connection post?
You would expect all batties to be at the same potential even in the daisy chain, so is this based on resistance of each connection and presuming the chain is made by hooking one on, one off, rather than the chain being a continuous conductor with multiple post connectors?

[OS2Dude]

Originally Posted by shrspeedblade

I saw a tear down of one of these, I don't remember if it was Will Prowse or Sailing Temptress on YouTube (both very informative). It was a pouch cell, LiFe chemistry but a bit different, probably not as durable as prismatic cells. I'd go this route if space was the absolute critical factor, but prismatic or cylindrical otherwise.

Will Prowse did one. (See time 7:45)

https://www.youtube.com/watch?v=P0_YpKKdst8

[SV Confianza]

I added 6 of these to my bank last sept. Going strong so far, but it’s pretty early.

[SV Confianza]

Originally Posted by s/v Jedi

They state somewhere that you can connect four in series, four in parallel… I’m thinking why the limitation for parallel? Series is because of the maximum voltage rating of the MOSFETs of the BMS…

Seems to be that most LFP companies say this. I would bet it only has to do with them not being comfortable with the amount of amps available in the bank and overheating 4/0 wires in case of a short and bms cutoff failure?

[JBP]

Litime is a pretty well known brand of drop-in replacement batteries. LFP has more energy density than lead AGM, first they had 100ah in a group 24 case, and now the mini is even thinner (but a bit taller I think). Will Prowse says they look OK so I suspect they are OK drop-in batteries.

[Bellinghamster]

100AH Group 24 size now with bluetooth: https://www.litime.com/products/liti...-1280wh-energy
(no affiliation, I don't even have LiFePo4 batts (yet))

Question for anyone with multiple bluetooth batteries - do they need to be connected to/monitored individually? Can you get a summary of the whole "system"? Seems to me the bluetooth connection is under OS control, not app control, so you'd need to connect the (phone/tablet, etc.) to each battery in turn. Maybe not? I've only ever connected to one bluetooth device at a time...

[Letterkenny]

Originally Posted by JBP

Litime is a pretty well known brand of drop-in replacement batteries. LFP has more energy density than lead AGM, first they had 100ah in a group 24 case, and now the mini is even thinner (but a bit taller I think). Will Prowse says they look OK so I suspect they are OK drop-in batteries.

Well they were more group 27. Litime just recently came out with a group 24 drop in.

[fourlyons]

Originally Posted by Bellinghamster

100AH Group 24 size now with bluetooth: https://www.litime.com/products/liti...-1280wh-energy
(no affiliation, I don't even have LiFePo4 batts (yet))

Question for anyone with multiple bluetooth batteries - do they need to be connected to/monitored individually? Can you get a summary of the whole "system"? Seems to me the bluetooth connection is under OS control, not app control, so you'd need to connect the (phone/tablet, etc.) to each battery in turn. Maybe not? I've only ever connected to one bluetooth device at a time...

I have Epoch lithium batteries, and yes, you have to connect to each sequentially to check them. If there is a way to get a group summary through Bluetooth, I don't see how. Having said that, I can see the relevant data from my two Victron solar regulators in the Victron app, so maybe it is possible.

I have a separate battery bank monitor, that I used originally with the lead acid batteries. I don't have enough experience with the system yet to say how accurate the old monitor is with the new batteries.

[CaptainRivet]

Problem with this small batteries and its even cheaper and basic BMS is that non of them alone can support any of the critical loads as backup to starter. It will die instantly if you try to start the engine with it or bring up the anchor...neither the BMS nor the pooch cells are capable of that.
The current especially surge and peaks are not distributed evenly between the batteries and the first in row will get much more wear then the other throwing that 6 parallel more off with every cycle.
Ok if you have a very small vessel with a 6" chain and a 10hp thats acceptable but eveything else you gotbthe wrong ones. Get 3 of the 200A with 1p4S and a 200A BMS or better 2x300AH if the have instead 6x100A as each single battery is capable of driving the critical loads on your boat.

The theory that all parallel are equal and equally discharged/charged is a theory, real world looks different.
These 100AH are good for cheap,lightweight and small service on an RV as a lot have a load capacity problem to drive smaller inverters and energy needed of a smaller RV. Wrong for any bluewater vessel, a small daysailor ok.

Well a 304AH battery with EVE from sunfunkits with 304AH cells is cheaper, smaller, weight less and much better quality then 3x100AH of these.
You could take 1 of these 304AH ones and add the 100AH additionally to capacity you want if you really want or eg due to insurance need drop ins. But i would simply take 2 of these EVE/sunfunkits then 6x100AH li-time

[CaptainRivet]

Originally Posted by SV Confianza

I added 6 of these to my bank last sept. Going strong so far, but it’s pretty early.

Thats a good way if you have capable LFP already which can also emergency start your engine and add the 100AH ones to get capacity you like. Like this they see very little current as the main load is carried by the other LFP.

Also like Jedi have it with winston and add 200AH LI-TIME for more capacity.
With the cheap 100AH for 259Euro you have the issue that you have no idea what eg 6x100AH are doing. Adding a battery monitor to each 100AH battery so you at least whats going on per battery is 60Euro for a cheap one or 130 for a victron smart shunt per battery, half the price of the 100AH battery. Or if a BMV 712 to have correctly a desaster shut off the BMV712 costs as much as the battery, Makes economically no sense.
One for all 6 in parallel makes simply no sense as ypu don't see what each one is doing.

Like jedi has it with a 24V 200A it makes economically sense to a smartshunt or better BMv712.

[CaptainRivet]

Originally Posted by SV Confianza

Seems to be that most LFP companies say this. I would bet it only has to do with them not being comfortable with the amount of amps available in the bank and overheating 4/0 wires in case of a short and bms cutoff failure?

Yes they do because they have mosfets BMS and the mosfets are NOT calibrated means for the first milliseconds one poor weakest mosfet has to carry all the load and the more in parallel the more load is on that one mosfet during that milliseconds and it doesn't even need a big load to fry them=slow death of the BMS as the mosfets will die one after each other over time leaving less mosfets to carry the loads. The mosfets are oversized so till smoe load one can carry that load but if you put more in parallel the load on that weakest mosfets exceeds its current spec even during a light load on the 6x100Ah. Thats why limit on 3 or 4 in parallel.
Thats why i always recommend the biggest capacity with the biggest cappacity BMS as the mosfets are bigger in current rating.

Rule of thumb if a 12V 200A mosfet BMS (not the total battery with cells, just BMS) is below 350Euro it cannot have calibrated mosfets even if purely chinese build and sold via its on webshop.
Calibrated means all mosfets are identical and switch in the exact milliseconds synchronized, not calibrated mosfets don't and there is always one weakest who get the total load in the first milliseconds.

Eg the mueller energy BMS 250A build by jk for mueller is based on the 300A JK BMS and has calibrated mosfets and cost 470Euro. The 300A JK equivalent is 180-230Euro depending on balancer with uncalibrated mosfets.
I wouldn't hesitate a sec to put 750A on 3 mueller energy 250A BMS in parallel but not more then 450A on 3x300A jk bms because of that.