Anyone seen this scientic* Battery Test article - *supposed

[themexicandoctor]

https://www.mortonsonthemove.com/bes...-test-results/

I do have input from a Battleborn employee & a leading AGM employee saying this process while seeming exhaustive to a neophyte (like me), has some glaring errors.

What do you guys think?

[booster]

Originally Posted by themexicandoctor

https://www.mortonsonthemove.com/bes...-test-results/

I do have input from a Battleborn employee & a leading AGM employee saying this process while seeming exhaustive to a neophyte (like me), has some glaring errors.

What do you guys think?

As soon as they said they charged the batteries to the "manufacturers specifications" with stating what specification they used. AGM many say a full battery is 12.6-12.8v but that will leave them undercharged bey over 10% most of the time. The only way to get to true 100% full is to charge to the tail charging amps in absorption voltage, IMO, and all the better AGM battery manufacturers have the spec available. If a lithium manufacturer says charge to 14.7v they are putting the battery at risk based on the latest information that wants some head space in use.

[themexicandoctor]

As always, your educated answer is over my Head BUT I do know you are right.

You are talking about the 10% loss I believe.

[avanti]

One problem is that the author cherry picks which parameters he measures vs those he accepts from the manufacturer. For example, he claims to prove that the OEM capacity numbers are inaccurate, but happily takes lifetime cycle counts published by those same OEMs and uses them to calculate lifetime costs, accepting them as facts. If we can't believe the former, why should we believe the latter? Answer: Because the latter support his desired conclusions.

[themexicandoctor]

Thank you Gentlemen.

It comes across as such a detailed, intelligent & unbiased test but then both a Battleborn & Lifeline Employee stated something very similar to "There is so much wrong with this but one needs a few years in the battery industry to understand just how flawed this is ..."

[booster]

Originally Posted by avanti

One problem is that the author cherry picks which parameters he measures vs those he accepts from the manufacturer. For example, he claims to prove that the OEM capacity numbers are inaccurate, but happily takes lifetime cycle counts published by those same OEMs and uses them to calculate lifetime costs, accepting them as facts. If we can't believe the former, why should we believe the latter? Answer: Because the latter support his desired conclusions.

We have 4 Lifeline batteries and I tested the capacity when we got them. I charged to full based on tail amps and discharged at the 20hr rate at the rated temperature. I got about 5% more than rated capacity. If they did not make rated, then the likely didn't have them full because the charged to voltage or time.

[RossWilliams]

Any information from "influencers" needs to be taken with a grain of salt whether they clearly identify themselves as such or not. Companies don't cooperate with people who might produce a story that doesn't reflect well on their product.

That said, its important to always remember that manufacture specs are based on a specific set of conditions that may not apply to our actual usage. In fact, they almost certainly won't.

Whether lithium batteries problems working in cold are a "myth" depends on what you mean by "cold". Where I live, freezing temperatures next week will be a warm spell. My understanding is that most lithium batteries can't be used at all when the temperature of the battery gets well below zero. I don't know how you would heat the battery at that point without some other source of energy. On the other hand, nighttime temperatures slightly below freezing are unlikely to get the battery temperature cold enough to prevent charging.

What I want is a battery bank I can easily use without abusing. AGM's seem to do that without a lot of technical knowledge. Lithium's depend a lot on the RV manufacturer being competent with relatively cutting edge technology. That is a roll of the dice.

[Davydd]

Volta lithium ion 48v systems are all in conditioned spaces (inside the van.) My Valence 12v batteries are inside the van. My Elite Power Systems batteries were under the van in an insulated shell protected by a steel cage and heated. Other lithium battery systems are self-heating and if you have a high amperage array self-heating takes little energy out percentage wise. Inside the cabin batteries will most likely be above freezing unless you self-flagellate and drive with no cabin heat from the engine or parked with no heating system. So, they will not need a heat source fed off itself. ARV in recent years have install in cabin batteries for every custom system they publicized.

Lithium ion batteries connected with no load I have observed are 4-6F above ambient. When a load is applied like refrigerator on and normal use batteries jump to over 10F, so if you are camping in mid twenty temperatures your batteries probably are above freezing and chargeable. I’ve endured as I have mentioned a week on the road 24/7 of temperatures alway below freezing down to a -5F without shore power. Actually my first week in Alvar Elite outside batteries coming from Cleveland, to home in Minnesota and all the way down to Gallup, NM waking up to 0F before it finally got up above freezing in Arizona. I’m comfortable with cold temperatures and have traveled twice when it got down to -15F. The 800ah Elite battery bank outside the van was heated off the batteries with two 5a electric heating pads that I observed only on about half the time so maybe it consumed 120ah in 24 hours. For me with a second alternator I can replenish that in a half-hour of driving. My heating source for the cabin is a diesel-fired heat exchanger that sips about 1/4 cup/hour.

There is no myth. It’s highly manageable and I remind everyone it is the only way to travel transparently using all systems like microwave, coffee pot, 120vac outlets same as if you are on shore power and without conserving batteries while boondocking simply because in a Class B van you simply cannot add AGM batteries to match lithium ion capacity because of weight and space limitations and with 5,000 cycles vs. 500 if you plan to keep your van that long lithium ion’s life cycle cost is cheaper.

I like boondocking or being unplugged to shore power and the convenience of an all electric van all the time without restrictions in use. I like not having to have solar panels on my roof so I can have two skylights, AC, Maxxfan and a dome antenna on a short van, i.e. there is no room for solar panels that could possibly satisfy any needs for a high ah battery bank. I had 460 watts of solar panel on my previous van. It was a waste of money for all its contribution which was negligible when you have a second under hood alternator which is more convenient, versatile, less maintenance and charging efficient than an Onan generator. Solar panels are another maintenance headache, difficult to keep clean and take up roof space you could use for something else. I also like the freedom of not needing supplemental propane systems.

That’s my 7 years worth of owning two lithium ion powered Class Bs. That’s not armchair conjecture or rolling dice.

[markopolo]

Originally Posted by Davydd

.......................

Lithium ion batteries connected with no load I have observed are 4-6F above ambient. When a load is applied like refrigerator on and normal use batteries jump to over 10F, ........................

Davydd has mentioned a temperature rise previously. That seems to be tiny load relative to his large battery bank yet he observed a significant rise in temperature. It would take a lot of sustained heat to increase the temperature of a large mass such as a 600Ah or 800Ah battery bank.

I have 1200W toaster oven for RV use. I used a 58Ah LiFePO4 battery to power it. The load was 100A so it was a 1.7C discharge rate. I set the toaster oven on dark (max) and that takes just over 5 minutes. The battery pack temperature went from 68F to 73F, hardly noticeable. I checked multiple spots for temperature and didn't find any hot-spots. I ran the test twice.

As a comparison, a 1.7C discharge rate on a 600Ah battery bank would be a 1,020A load. It would be a 1,360A load on a 800Ah battery bank. Davydd's load would have been a fraction of that.

What could explain the minimal temperature rise at a very high discharge rate on my battery and Davydd seeing significant temperature rise from just running a fridge & stuff?

Heat from the cells own internal resistance is wasted energy. That heat generation reduces the remaining capacity of the batteries. It happens before any monitoring can take place so you would not even know it has been lost. It seems unlikely that the cells would heat up much with small C rate loads.

Does anyone else here have any data for battery heat rise with their system?

[RossWilliams]

"What could explain the minimal temperature rise at a very high discharge rate on my battery and Davydd seeing significant temperature rise from just running a fridge & stuff?"

The numbers indicate an increase of 4-5 degrees in both cases, from 6 to 10 degrees over ambient in one case and from 68 to 73 in the other. You ran your toaster over for 5 minutes, presumably the refrigerator was on continuously pulsing on and off to maintain temperature.

[markopolo]

That suggests that a 5A or 10A or so load causes/generates enough heat to make a huge mass (600Ah or 800Ah) battery bank's temperature to rise by 5 degrees.

The 5 degree increase on mine was a 100A load on small object, a 58Ah battery.

Also, Davydd's battery sits at 5 degrees over ambient for some reason. Where does the heat come from? Whatever was heating the battery then might have caused the heat rise he thinks occurs inside the cells.

[Davydd]

I can get a read out of my lithium ion batteries at all times through my Silverleaf touch screen monitor. I have four Valence lithium ion 12v batteries. They are U27-12XP 144ah drop in modules for 576ah. It monitors the temperature of each battery separately down to each cell. This is the temperature screen of page 5 of 5. That's how I know the temperature at anytime.

[markopolo]

Originally Posted by Davydd

................

Lithium ion batteries connected with no load I have observed are 4-6F above ambient. ........................

What was the ambient temperature?

How can something be 4-6F above ambient with no load? Were they being charged? If not, what it is source of heat that is causing what you see? Was it residual heat from previous use? Calibration errors? Heat from the electronics? Heat from the van or van systems?

There has to be an explanation for what you observed. The batteries would not be using energy (draining themselves) and creating heat. The self-discharge would terrible if so.

[Davydd]

Originally Posted by markopolo

What was the ambient temperature?

How can something be 4-6F above ambient with no load? Were they being charged? If not, what it is source of heat that is causing what you see? Was it residual heat from previous use? Calibration errors? Heat from the electronics? Heat from the van or van systems?

There has to be an explanation for what you observed. The batteries would not be using energy (draining themselves) and creating heat. The self-discharge would terrible if so.

I said my batteries are alway connected in storage on shore power so I can use the water pump, microwave, Keurig, lights, etc. and charge them. I mentioned minimum use but underway with refrigerator on, coffee maker plugged in, microwave, lights, etc. normal use the temperature rises. No theoretical speculation is what I am saying. I also know exactly how much batteries are charging and how much they are discharging. When they are 100% charged the inverter and charging will shut down and the batteries in storage will discharge to about 88% before cycling on and charging again.

I use my condo garage as my man cave and wood shop so also utilize my Class B. At the time of this photo it was charging and it was reaching its peak. If I took a photo little later it would show a minus amp number, probably 0 to about -3a and the charger would be off and on standby. That +8a was winding down. If the batteries were at 88% that number would be over 100a charging. It's all observable real time. My garage fluctuates from a minimum of 55 degrees right now because of my furnace setting and about 78 degrees maximum in the summertime with no AC because it is nestled in a bank of garages on sides and back and well insulated on the roof I assume including 2" on the OH door.

This is the DC Power Screen readout.

[markopolo]

That didn't answer my temperature related questions at all.

Originally Posted by Davydd

I can get a read out of my lithium ion batteries at all times through my Silverleaf touch screen monitor. I have four Valence lithium ion 12v batteries. They are U27-12XP 144ah drop in modules for 576ah. It monitors the temperature of each battery separately down to each cell. This is the temperature screen of page 5 of 5. That's how I know the temperature at anytime.

You probably have 1,600 18650 3.2V cells (18mm*65mm) so cell level monitoring is not an option. What looks to you to be one cell would be a group of 100 cells in parallel.

5.4F differences between hi/low boards .........
5.4F differences between hi/low cell groupings .........

Maybe it's mostly explained by module accuracy tolerances.

[Davydd]

Originally Posted by markopolo

That didn't answer my temperature related questions at all.



You probably have 1,600 18650 3.2V cells (18mm*65mm) so cell level monitoring is not an option. What looks to you to be one cell would be a group of 100 cells in parallel.

5.4F differences between hi/low boards .........
5.4F differences between hi/low cell groupings .........

Maybe it's mostly explained by module accuracy tolerances.

Probably? It says 4 cells to one module (battery). What makes you think 1,600? Have you investigated the Valence batteries? Do you have an accurate way to tell? But whatever... I can't dwell on my navel anymore to investigate lint. I just know enough to know how my batteries are performing and have 7 years of experience to have confidence.

[markopolo]

All of the tear-down images of Valence batteries I've seen (XP & RT) show loads of the 18650 cells inside the cases.

Archived Valence pages show 18650 cells then later included 26650 (26mm*65mm) cells.

There was also this from Lithion:

Lithion Battery manufactures highly differentiated, high performing Lithium Iron Phosphate (LFP) cells for a variety of applications, across many sectors of industry, including: ESS, UPS, Medical, Industrial, Defense/Navy and Robotics. Our safe and reliable LFP cells are utilized as single cells and in multiple to build cell-packs and modules such as our industry-leading Valence battery modules. Designed to meet the needs of critical applications, Lithion Battery currently manufactures cylindrical LFP cells in both 18650 and 26650 form factors.

From the archived Valence pages, Valence had 2.5Ah & 3.15Ah 26650 cells in addition to the 18650 cells.

Four of the BCI Group 27 size batteries would contain around 1,600 of 18650 cells or 700 to 900 of the 26650 cells depending on which was used to get the capacity you mentioned.

Regardless, per cell monitoring isn't an option when dealing with that number of cells.

There's a tear-down video of an RT series (not XP) here:

https://www.youtube.com/watch?v=IS3OAhOgzOQ

The RT battery shown has an internal BMS with MOSFETs. The XP series has an external BMS with contactors from what I've seen. The video shows temperature probes near groups of cells.

[booster]

I have always wondered about spiral cells and heat generation, even back on the original Optima spiral AGMs. I would think the furthest in cells would run substantially higher temp than the outers if they all were generating the same amount of heat like would be, I think.

[markopolo]

Prismatic cells and cylindrical cells are both wound cells as far as I know. Somewhat like a jellyroll. A round jellyroll or a flat jellyroll.

jellyroll.jpg

Pouch cells can be flat-stacked or Z -stacked but there some illustrations show them wound.

Both prismatic and pouch cells can bulge and get damaged from that but cylindrical cells can't bulge so I'd think they have a structural advantage. If cylindrical cell holders are used in the assembly then the cells don't make contact with nearby cells. There's an air gap around each cell so heat from one cell doesn't transmit to other cells as easily as other types I presume.

[Davydd]

Originally Posted by markopolo

All of the tear-down images of Valence batteries I've seen (XP & RT) show loads of the 18650 cells inside the cases.

Archived Valence pages show 18650 cells then later included 26650 (26mm*65mm) cells.

There was also this from Lithion:

From the archived Valence pages, Valence had 2.5Ah & 3.15Ah 26650 cells in addition to the 18650 cells.

Four of the BCI Group 27 size batteries would contain around 1,600 of 18650 cells or 700 to 900 of the 26650 cells depending on which was used to get the capacity you mentioned.

Regardless, per cell monitoring isn't an option when dealing with that number of cells.

There's a tear-down video of an RT series (not XP) here:

The RT battery shown has an internal BMS with MOSFETs. The XP series has an external BMS with contactors from what I've seen. The video shows temperature probes near groups of cells.

Good find, Marko. I don't know if they are the same batteries. Looks smaller and Prowse mentioned Magnesium. The batteries were first marketed by Valence as Lithium ion Manganese, LiFeMgPo4, batteries. They are now LiFePo4 batteries that I have. Valence, I think, filed bankruptcy. Lithiumwerks then had the batteries and now Lithion. Made in China? Isn't just about most every lithium battery made there?

It was an interesting video. I didn't know they were so complex. Cripes, those are little computers! I don't know how you got 18,650 or so cells if a cell is like an individual round cylinder. If cylinders were about 1" diameter it looks like, maybe 256. The cell, as reported on the Silverleaf, could be grouped together with four reporting from that circuit board. It's beyond my expertise to contemplate or necessary for me to know. Will Prowse was impressed it seems. That's OK by me.

Food for thought, if those batteries were around $1,200 and with 10 times the cycles wouldn't they be equivalent to a $120 AGM battery? Just simple math. I don't expect to have my van for 5,000 cycles anyway. So that is just academic. I think I get superior performance out of them over AGM and as mentioned I couldn't get the equal AH capacity in my van with AGMs because of space limitations and weight. I was battling to get the weight down to stay with a 2500 chassis. I reduced the batteries from 6 to 4 in the process and gained two under bed drawers.