Moving to Li-Ion battery...which brands? BMS?

[superhawk996]

For comparison, the retired UPS batteries in my diesels are rated at 78ah and have a measured CCA of over 1200.  Their actual cranking performance seems to support what the tester said they could do.  I was quite surprised with their cranking ability since they're small, a couple years old, and not designed for cranking.  They do weigh as much as bigger batteries, that part jives with the high power.

[superhawk996]

15 minutes ago, xrated said:

No, I'm not confusing the two.  Generally speaking, LFP batteries intended purpose is what is typically called Deep Cycle type batteries.  Having said that, will they crank engines over?......the answer of course is based on the load current for the starter, and just how much peak or pulse current that they can provide without triggering the controlling BMS that is built into them.  Mine for example, will easily start the onboard Onan 5500W generator with absolutely zero (no pun intended) issues.  That starter on that generator will normally pull in the 100 to 110 amps while cranking the engine to life.

 

And as far as my DIY battery cells, the data sheet does say that for a "peak pulse", it can do 2C for 30 seconds.  The key to that number though is that the standard 1C discharge rate is equal to 250 amps.  So yes, the cell itself is capable (so they say) of doing 500 amps for a max. time of 30 seconds.....but again, we are talking about a BARE CELL.....not a completed battery that is controlled by a BMS.  And here is the important thing to remember in this conversation....Just ONE of my Four cells, is larger than the ENTIRE NOCO battery in question here, and the battery of course is comprised of 4 LiFePO cells internally connected in series to to get to the nominal 13.2V of a LFP battery.  So if ONE of my cells can produce 500A for a peak time and the entire NOCO battery is smaller than one of my cells, it is simply not realistic that the NOCO is able to produce a 500 amps....even at Peak or Pulse.  As Carlos stated earlier though, it really doesn't matter that much if all the advertised ratings are being greatly exaggerated.  The battery's purpose is likely sized to be able to start a motorcycle, garden tractor, snowmobile, jet ski, etc.  Those engines just do not have the starter current draw of say a car/truck engine or maybe a boat engine with a 350 cu in V8 motor in it

I have a pair of Xing Cell brand car size batteries that my friend bought that I think are garbage.  I don't know what the quality of the cells is, no markings on them makes me think generic crap.  There's no BMS which scares me away from using them.  On a 6a charger one group of cells went over 4 volts while another was around 3.2v.  The 4+ was still rising when I killed the charger.  Is this as dangerous as I think it is?  Potential for fire, or just potential death of the cells?  Is there a cheap BMS you would recommend for using them as starting batteries?

 

The case is car sized, the bundle of cells inside is about the size of a Harley battery, maybe a bit smaller.  They measure 500CCA on my simple tester and a little lower on my better tester which analyzes them with a load and with charging current.  I tried them in a boat with a 3 liter 4 cylinder inboard and my 6 cyl. 3.2L. Porsche and they cranked about as expected for 500CCA.  I later discovered the lack of a BMS, I'm glad I didn't leave either one in the vehicles for actual use.

[superhawk996]

Photos of the internal beauty.  4 groups of 7 cells and a small circuit board.  I don't know what the board is supposed to do, but it has tiny LEDs that I've seen light up red when a group of cells went way high or way low.

 

 

[superhawk996]

One more derailment/battery question.  This is for the UPS batteries I'm running in the diesels, also as a house battery for the motorhome.  If I'm understanding and converting the "watts per cell" correctly, it means that the battery can put out a bit over 150 amps for 15 minutes from fully charged to discharged; is that correct?

 

My math: Fully charged cell, just over 2.1v- 300w would be around 140a.  At 1.67v 300w would be just shy of 180a.

UPS12-300MR Specifications

• Voltage: 12 volt
• Amp Hour: 78.6 AH at the 20 hour rate
• Watts per Cell: 300 at 15 minute rate to 1.67 VPC
• Terminal Type: Threaded Receptacle
• Normal operating temperature range -40F/-40C to 160F/71C
• Float charging voltage 13.65 ± 0.15 VDC average per 12V unit (6.75 to 6.90 per 6V unit)
• Charging current – can be safely recharged at high current rates
• Flame retardant case and cover meet UL 1778

[Zero Knievel]

Page 5 here we come!  

[tomek]

23 minutes ago, Zero Knievel said:

Page 5 here we come!  

Pessimist. 

[SwampNut]

2 hours ago, xrated said:

No, I'm not confusing the two.  Generally speaking, LFP batteries intended purpose is what is typically called Deep Cycle type batteries.  Having said that, will they crank engines over?......the answer of course is based on the load current for the starter, and just how much peak or pulse current that they can provide without triggering the controlling BMS that is built into them.  Mine for example, will easily start the onboard Onan 5500W generator with absolutely zero (no pun intended) issues.  That starter on that generator will normally pull in the 100 to 110 amps while cranking the engine to life.

 

And as far as my DIY battery cells, the data sheet does say that for a "peak pulse", it can do 2C for 30 seconds.  The key to that number though is that the standard 1C discharge rate is equal to 250 amps.  So yes, the cell itself is capable (so they say) of doing 500 amps for a max. time of 30 seconds.....but again, we are talking about a BARE CELL.....not a completed battery that is controlled by a BMS.  And here is the important thing to remember in this conversation....Just ONE of my Four cells, is larger than the ENTIRE NOCO battery in question here, and the battery of course is comprised of 4 LiFePO cells internally connected in series to to get to the nominal 13.2V of a LFP battery.  So if ONE of my cells can produce 500A for a peak time and the entire NOCO battery is smaller than one of my cells, it is simply not realistic that the NOCO is able to produce a 500 amps....even at Peak or Pulse.  As Carlos stated earlier though, it really doesn't matter that much if all the advertised ratings are being greatly exaggerated.  The battery's purpose is likely sized to be able to start a motorcycle, garden tractor, snowmobile, jet ski, etc.  Those engines just do not have the starter current draw of say a car/truck engine or maybe a boat engine with a 350 cu in V8 motor in it

 

It's interesting that we've both spent many years using and researching LiFePO4 batteries and managed to "learn" opposite things.  Most of my applications have been for high current, because that is what they are great at.  Lipos do this in super-high current demands...

 

 

 

LiFePO4 packs can do insane current and barely warm up--both in and out.  I can't even remember what C levels I've run them to, but the only time I managed to damage a very large pack (with lots of heat buildup) it was depleted in under five minutes.  It had multiple series and parallel cells in one unit.  That boat was able to run multiple packs or singles, in various series/parallel configurations.  Well I left the motor controller in full mode with a single pack.  It may still be on fire at the bottom of Lake Pleasant.

 

 

 

[superhawk996]

1 hour ago, SwampNut said:

It may still be on fire at the bottom of Lake Pleasant.

Maybe that's what got rid of the Quagga mussels.

[xrated]

6 hours ago, superhawk996 said:

I have a pair of Xing Cell brand car size batteries that my friend bought that I think are garbage.  I don't know what the quality of the cells is, no markings on them makes me think generic crap.  There's no BMS which scares me away from using them.  On a 6a charger one group of cells went over 4 volts while another was around 3.2v.  The 4+ was still rising when I killed the charger.  Is this as dangerous as I think it is?  Potential for fire, or just potential death of the cells?  Is there a cheap BMS you would recommend for using them as starting batteries?

 

The case is car sized, the bundle of cells inside is about the size of a Harley battery, maybe a bit smaller.  They measure 500CCA on my simple tester and a little lower on my better tester which analyzes them with a load and with charging current.  I tried them in a boat with a 3 liter 4 cylinder inboard and my 6 cyl. 3.2L. Porsche and they cranked about as expected for 500CCA.  I later discovered the lack of a BMS, I'm glad I didn't leave either one in the vehicles for actual use.

Not having a BMS for them would be a no go for me...Dead Stop!  The group of cells that went to 4 volts is likely toast.  If they are in fact LFP chemistry, they are "safer" than Li-ION battery as far as fire/explosion but I'd never try to use them without a BMS.  The DALY brand BMS that I bought is one of the cheaper ones out there and IIRC, the 200A Smart version that I bought (smart meaning BlueTooth equipped to communicate with the DALY app.) was still over $100.  You would obviously need something much larger for a BMS for starting a car/truck.  If the battery was "newish" it might be worth buying a BMS for it, but considering it is not, plus you know that at least one set of cells has been WAY overstressed with 4+ volts, I don't think I'd be doing it.

 

And the small internal printed circuit board could possible be a balancer board....but that is just a wild ass guess on my part.

[superhawk996]

5 hours ago, xrated said:

And the small internal printed circuit board could possible be a balancer board....but that is just a wild ass guess on my part.

Maybe.  When I opened the second battery the 4 groups of cells were nearly perfectly balanced as far as resting voltage, but as soon as I started charging one group of cells went way higher than the others, I stopped and didn't do any more investigating.  It sounds like the smart thing is to drop these in the trash can and forget they existed.....which means I have to test/torture them to learn more first.

[xrated]

8 hours ago, superhawk996 said:

Maybe.  When I opened the second battery the 4 groups of cells were nearly perfectly balanced as far as resting voltage, but as soon as I started charging one group of cells went way higher than the others, I stopped and didn't do any more investigating.  It sounds like the smart thing is to drop these in the trash can and forget they existed.....which means I have to test/torture them to learn more first.

LOL........"test/torture" comment.  Have fun testing/learning.  I remember back when I did the initial, and so far the only top balance on my cells after I built them and can remember thinking......this is the true test of the "quality" of my build, the cells, and all my newly made connections.  With a bit of tweaking, my final top balance resulted in in three of the four cells hitting the 3.65 and the other hitting 3.64.  After pulling the balance charger off of the battery and letting it rest, all four cells were the exact same voltage.  Even today, two plus years later, after a full charge on the battery (I use 14.2 volts as the max, not 14.6) I will see them settle down and usually end up with .002 volts to maybe .003 volts differential between the highest cell and the lowest cell reading.  That number is perfectly acceptable and personally I would not get too concerned unless the differential voltage gets somewhere north of .050 volts while they are charging, and/or doesn't drop down to .010 volts after resting.  Like I stated above, mine usually hit the .002 to .003 volts after a charge and then a resting period.  I usually check that out after about 4 hours of resting after a charge.

[ptxyz]

both my friend and i have had these in our blackbirds for several years without issue.  at least twice, i've run mine down to not even enough for dash lights and after charging (lithium specific charger or using a jump battery and charging via the bike's alternator), it's been fine.  i've read once they drop below a certain voltage, they disconnect to avoid completely draining.

 

https://bansheebatteries.com/collections/lithium-motorcycle-batteries

Edited May 30 by ptxyz

[xrated]

47 minutes ago, ptxyz said:

both my friend and i have had these in our blackbirds for several years without issue.  at least twice, i've run mine down to not even enough for dash lights and after charging (lithium specific charger or using a jump battery and charging via the bike's alternator), it's been fine.  i've read once they drop below a certain voltage, they disconnect to avoid completely draining.

 

https://bansheebatteries.com/collections/lithium-motorcycle-batteries

Any LFP battery worth it's weight in salt would have a BMS AND a low voltage cutoff as part of that same BMS.  LFP lower cutoff should never allow a cell to go below 2.5V or 10 volts for the battery.  They are recoverable at that point, but if for some reason the BMS's LV cutoff failed to stop the LV, it's almost certain the cell(s) would be ruined.  And the opposite of that is the High Voltage cutoff.  It should stop any cell to not go over the 3.65 volt level or 14.6 volts for the battery.

[Banshee]

On 5/29/2024 at 2:44 AM, xrated said:

I'm calling BULLSHIT on the "500" amps of starting power.....that's not happening.  My 302AH EVE cells that I used for building my battery, which by the way, One of those four cells for my battery is larger than the entire battery of 4 cells of the NOCO battery.  The max. current limit on my cells are 1C....which means 302 amps.  Like I said, I'm calling BS on the Amazon ad for that particular stat.

 

You really should avoid the specs listed for Amazon LED torches then!  They will not do your heart rate ANY good, whatsoever.

Edited May 30 by Banshee

[SwampNut]

I ordered one that can do 57,000 lumens from a single AAA.  I'm going to aim it at a solar panel and get free power.

 

[xrated]

13 hours ago, Banshee said:

 

You really should avoid the specs listed for Amazon LED torches then!  They will not do your heart rate ANY good, whatsoever.

My modified terminology for pretty much everything on Amazon in regard to specs, changes the original statement of "Trust, but Verify" .......to....."NEVER Trust, and ALWAYS Verify"

[superhawk996]

15 hours ago, xrated said:

Any LFP battery worth it's weight in salt would have a BMS AND a low voltage cutoff as part of that same BMS.  LFP lower cutoff should never allow a cell to go below 2.5V or 10 volts for the battery.  They are recoverable at that point, but if for some reason the BMS's LV cutoff failed to stop the LV, it's almost certain the cell(s) would be ruined.  And the opposite of that is the High Voltage cutoff.  It should stop any cell to not go over the 3.65 volt level or 14.6 volts for the battery.

The NOCO I had in the Harley definitely had a low cut-off, and it seemed to be very conservative, but I didn't have a voltmeter on it when it cut.  The Battery Tender brand I've had in the Birds either doesn't have a low cut or it's low enough that the battery is obviously low before it cuts.

[superhawk996]

1 hour ago, xrated said:

My modified terminology for pretty much everything on Amazon the planet in regard to specs, changes the original statement of "Trust, but Verify" .......to....."NEVER Trust, and ALWAYS Verify"

FTFY.

[IcePrick]

[SwampNut]

29 minutes ago, IcePrick said:

 

 

Ok, dunno who that is, or why it's related, but it's either AI or trans?  I think?  Call me a homo but it's not up to spec.  Big shoulders, fake lip, fake nose, fivehead...

[IcePrick]

Former penis owner.  

[RXX]

Is there a problem with AGM batteries?

[Zero Knievel]

25 minutes ago, RXX said:

Is there a problem with AGM batteries?

Normally, no, but BMW of late is notorious for specifying batteries just large enough to start the bike if it hasn’t been sitting too long.  You can’t install a larger battery because the battery space is limited to what they designed for.  Add that all the computer stuff and keyless ignition creates a parasitic drain to the point that ever with a good battery you need to top off if the bike’s been sitting for a week.

 

The Big Crank I installed should have been an improvement, but even though I topped of shortly before loading the bike, I had starting issues on my Kentucky trip and had to borrow someone’s trickle charger to get the battery so it would start reliably.  It’s really a dumb design choice.  The XX is essentially analog compared to the modern BMW.  The computer will not allow a start if the voltage is too low…even though a regular bike could still crank and start at that level.  If I’m working on anything electrical and need to have the bike powered on, I have to have it on a trickle charger or in as little as 10 minutes I’ll get a low battery warning.

 

Hence, several BMW owners have switched to lithium since it has more capacity than AGM.

[IcePrick]

3 hours ago, Zero Knievel said:

Normally, no, but BMW of late is notorious for specifying batteries just large enough to start the bike if it hasn’t been sitting too long.  You can’t install a larger battery because the battery space is limited to what they designed for.  Add that all the computer stuff and keyless ignition creates a parasitic drain to the point that ever with a good battery you need to top off if the bike’s been sitting for a week.

 

The Big Crank I installed should have been an improvement, but even though I topped of shortly before loading the bike, I had starting issues on my Kentucky trip and had to borrow someone’s trickle charger to get the battery so it would start reliably.  It’s really a dumb design choice.  The XX is essentially analog compared to the modern BMW.  The computer will not allow a start if the voltage is too low…even though a regular bike could still crank and start at that level.  If I’m working on anything electrical and need to have the bike powered on, I have to have it on a trickle charger or in as little as 10 minutes I’ll get a low battery warning.

 

Hence, several BMW owners have switched to lithium since it has more capacity than AGM.

 

Battery disconnect switch?

[CBR-RR-XX-CESS]

12 hours ago, SwampNut said:

Big shoulders, fake lip, fake nose, fivehead...

And her head is not attached to her neck properly.