Ultimate Battery Thread

rando said:
Sounds like a fun project! Keep us abreast of how it all goes.

Three years ago when I was working on my lithium batteries, the bare cell cost for prismatic cells was not enough less than the cost of drop ins to make that option worthwhile. Thus spending a lot of hour assembling old stock cylindrical cells into a bigger pack. Recently that has all changed and prismatic cells are now a fraction of the cost of battle borne and the like:
$580 for 280Ah@12V delivered.

Budget another $100 - $200 for the BMS, bus bars and enclosure and you are still 1/3 the cost of 3 battle born batteries with a lot less work.
Yep, ordered a BMS too. My cost will be around $300 when I'm done.
Prismatic vs Cylindrical. I might get slapped around here, but I believe all drop-in LFPO4 batteries, such as Battleborn, (& many others) use cylindrical cells. There are reasons why Prismatic cells are so “reasonably” priced. This is copied below but the pros & cons are as I remember them when I was considering DIY Battery construction. When the cost became more significant with cylindrical cells, which I wanted, I decided it was too pricey, vs prismatic, to take a chance with my material investment. I wanted accurate BMS functionality, efficiency & safety. The more knowledge about this, for me, the better.

Cylindrical Advantages

Compared to prismatic cells, cylindrical cells produce so much faster, so more KWh per cell can be produced every day, equaling lower $ per KWh. The electrodes in a cylindrical cell are wound tightly and encased in a metal casing, This minimizes electrode material from breaking up from the mechanical vibrations, thermal cycling from charging and discharging and mechanical expansion of the current conductors inside from thermal cycling. Many cells are combined in series and in parallel to increase voltage and capacity of the battery pack. If one cell goes bad, the impact on the entire pack is low. With prismatic cells if one cell goes bad it can compromise the whole battery pack. Cylindrical cells radiate heat and control temperature more easily than prismatic cells.

Prismatic Disadvantages

Prismatic cells are made up of many positive and negative electrodes sandwiched together leaving more possibility for short circuit and inconsistency. The higher capacity makes it difficult for the BMS to protect each cell from over charging and dissipating heat. The larger cell size minimizes the possibility for automation leading to a lower degree of consistency. The internal electrodes can easily expand and contract causing deformation which can lead to a internal short circuit and are more prone to swelling similar to lead batteries.
If the $/KWh were the same, I would definitely go with prismatic cells over cylindrical cells. I am only using cylindrical cells because they were a screaming deal at the time. If I built another pack today, I would use prismatic cells both because they are cheaper, are far easier to assemble and are likely more reliable in the long run.

There can be an issue with swelling of prismatic cells as the rectangular enclosures is not as inherently resistant to deformation as a small cylindrical housing. However, this is easily addressed by sandwiching the cells between end plates, using threaded rod or the like. This is a requirement for prismatic cells.

Cylindrical cells have the liability of a large number of interconnects, which in my mind with vibration and thermal cycling are more of a risk than internal defects in the cells. There is some redundancy with large numbers of cells in parallel, but there is also increased risk. If any of the cells happen to fail as a short, then they take the whole pack down. My battery has 120 cells in it, so the risk of this is 30x greater than a 4 cell pack.

I don't know for sure why battle born uses cylindrical cells, but I imagine it is because that is what they could reliably get at the time they started, and it allows them to arrange the cells to fit in standard lead acid form factors. It should be noted that Victron uses prismatics, and they certainly have better engineering and more experience than battleborn.
Interesting stuff. A 2017 JoPS Pub states ... “Prismatic LMO cells, offer more opportunities for large cell formats with thicker electrodes, have more design flexibility, require less hardware, thus reducing hardware costs per kWh. NCA and NMC cells, using a prismatic format, are more rate-limited than LMO counterparts.” I can understand the reasoning re electrode thickness, stacked vs wound. For now, I still trust BMS moderated cylindrical cells, from what I read, over prismatic.
Eventually I would like to build a battery. Prismatic does offer the value to make it tempting. I hope to learn by following some of the build threads. Initially, by the time I looked into extra Ah storage, cylindrical cells were not a tremendous deal.
I was satisfied with my 2yr old purchased battery. And even though I really wanted to build one, for my canoe, it seemed like mostly a gamble with the cost of materials. I then came across a company using the same tech/construction as mine, a bit later in generation, but significantly similar & attractively priced. The original entrepreneur for both had been on the cutting edge with lithium possibilities in the auto industry. I can mix/match mine in parallel, 200Ah if needed, in a pinch.

For a singular review, as always, here is a Will Prowse forum post ... His look at the competitors for LiFePO4 batteries ...

“Victron battery is winston cells (that are cheaper) that need external regulation and management.
Simpliphi costs $500 more for the same Wh capacity as a battle born.
Lion energy is $50 cheaper than battle born, but uses cheaper cells and off the shelf bms
Kilovault seemed good at first, but looking at the case and some complaints emailed to me, seems cheap, and relabeled
Aliexpress drop in replacements use dirt cheap cells and bms, and no low temp cut off
Re-lion sells same size, same feature battery for $300-400 more
Trojan trillion is also overpriced and capacity rating figures are over exaggerated (they rate the capacity to 70%, not the typical 80%). And they are hard to find.
Renogy battery is cheaper quality, and relabeled for 100$ less than battle born with less safety certifications”.

“Imagine if DIY was not an option, and you just want a battery that works. Most people are going to just go for battle born.
The biggest reason I like battle born is that I never hear any complaints”.

“For months, I would have people randomly email me ruixu battery failures (like the one that was mailed to me for my video), low temp cut off absence, diy batteries being over charged or bms not properly installed. It drove me nuts. If someone buys a battleborn, they get the customer service to set it up, and if it fails, battleborn will replace it. Less stress for me at the end of the day, and less chance of someone catching their house on fire”.
I have been trying to learn about batteries and the majority of this is greek to me. Please forgive the elementary questions but I am trying. Would like to change out my AGM batteries for lithium, the battleborn seems to be the battery of choice but I only have space for one 100 amp battery in my hawk, front dinette. I have 22 total inches in my cabinet and each battleborn is 12.75. Lion energy makes a model that is the same amps but smaller where I could fit two into my space. They are also lighter and cheaper. They don't seem to be made as well and I do not read much about them. Does anyone have any experience with the lion energy lithium batteries or have other suggestions. Thank you for your help.
I have been climbing the electrical knowledge ladder for about two years and have begun to grasp it on a users level. Hang in there it is at times daunting... confusing but folks here seem to have the patience of saints and have helped me a LOT. I replaced my two AGM batteries with the Battleborn. Just know that one Battleborn LiFePo4 battery is essentially equal to two AGM for usable energy. I can recommend them and say the customer support stood by their product when there was an issue. (which is extremely rare).
I have a 2014 Hawk front dinette. I replaced the factory AGM batteries with two Battleborn GC2 100 aH batteries. I had to remove one 1/2” spacer at the front bottom of the compartment. It is a tight fit but a fit nonetheless. The other Battleborn 100 aH battery is, essentially, a group 27 size.

I have an Intech Flyer Pursue trailer, also. In it, I installed a Lion Energy Safari UT 1300. Have had it only a few months but it works fine so far. An advantage is that it is a group 24 size. Two of these should drop into the Hawk battery compartment without any problem.

I'd go with battleborn just because they're close. Bout a three hour drive. My AGM's though look like they'll last a while longer yet.
If you need more AH, what about running 3 of the BB 50s in parallel? They are 6.75" length, so you should have room for 3.

An advantage to multiple batteries in parallel is that if one fails, you can just unhook it and run on the remaining good one(s).

As stated, are you sure you need more than 100AH? You can safely draw the LiFePO4 down at least to 20% SOC, vs 50% for lead acid.
Just pulled the trigger on a Renology 100ah LiPo at $899 less 15% during CYBERWEEK discount. $837.66 including tax and shipping.

We're tired of limping along on our 100ah AGM battery, hovering just above 12v most mornings. I've done cursory investigation on our Morningstar MPPT controller and the factory IOTA-DLS-30. They both say they will support lithium batteries, but I'm not sure. The new Renology battery will fit the existing factory battery box (nominal 7" x 12.75" x 8").

My concerns are whether the factory IOTA converter charger will do appropriate bulk, trickle, etc profiles
and whether the Morningstar MPPT-15L will do the same. We have a fixed 120w solar panel on the roof.

I did look at the Renology solar controller (RT) as better option, but their blue tooth app reviews are garbage. I've heard good things about Victron. Maybe I should do a hybrid with Victron controller, Renology LiPo 100ah battery, and keep the factory IOTA-30. I don't know much about BMS, but wonder if this "smart" battery plus a phone app / controller would fit the bill.
I added an IOTA IQ4? dongle when I bought the Hawk back in 2010, but I don't think they were optimized for LiPo batteries.
It was about twenty bucks back then. For $18 I'll get the IOTA IQ-LIFEPO, and that will fix the shore power concern.

Thanks Buckland!

That’s the one I got from the same vendor. It has worked well for me. Keep in mind that the Battleborn BMS is controlling the charging also.

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