Low priced LiFePO4 Batteries vs High priced

[T1 Terry]

The big difference in price seems to be split into two different parts, what capacity the battery really is and how well the BMS works.

The first part, check the C rate the capacity is measured with, as an example, C20 for a100Ah battery means you can only use a max of 5 amps if you want to get the 100Ah.
This adds a second catch with the cheaper batteries, is the capacity really 100Ah or does the seller use the 80% available trick meaning you only actually get 80Ah.

A 100Ah lithium battery should be able to provide 50 amps continuous for 2 hrs and each cell still remain above 3v while under load. This is called a C2 load rating, a battery with a C20 load rating will not deliver 50 amps for 2 hrs, many will not deliver 50 amps at any time period, the BMS will not allow that much current draw.

The high end price allows access directly to the cells, you can test, and if needed, replace a single cell, or charge a single cell, or clean the links between the cells. They will last 10yrs or more, that is the experience we have with the Winston cells we use and we have used hundreds if not thousands of these cells over the last 11 yrs building off grid power systems.

We get a lot of the lower price end drop in batteries brought in to see if we can fix them, and even some rather high priced drop in batteries. None have ever delivered the capacity marked on the case tested at 2C, some simply won't deliver 50 amps or accept a charge at 50 amps.

T1 Terry
T1 Lithium

[davil]

thank you, Terry, for your thoughts on the stated thread.

I am an average DIY boater, done all work in my boats with the average knowledge about electric components for over 50 years on several boats I have owned.

Have managed not to blow up any of my boats nor seriously damaged any components.

Will not disregard the "being lucky confusing with expertise"

During these postings, I learned a lot, one was alerting to Winston as a source of excellent products.

Ideally, the BMS seems to be the logical defense and alerting component and yet also the weakest part on the low cost end batteries.

By having each of my banks with 2 or more batteries in parallel, hope? to avoid catastrophic damage to the charging source (mostly the engine alternator).

More likely will not have a practical way to know one battery is now kaput, but only the total capacity of the bank is significantly diminished from the original 200 ah to 100

Because of the nature of the lithium batteries, cannot use a drop in voltage as an earlier indicator of problems.

That means the bank is charged more often.

If my line of thinking is correct, then I can live with this.

"the price is right"

I am not breaking the bank investing on the "higher cost end batteries"

thank you again for your patience.

Originally Posted by T1 Terry

The big difference in price seems to be split into two different parts, what capacity the battery really is and how well the BMS works.

The first part, check the C rate the capacity is measured with, as an example, C20 for a100Ah battery means you can only use a max of 5 amps if you want to get the 100Ah.
This adds a second catch with the cheaper batteries, is the capacity really 100Ah or does the seller use the 80% available trick meaning you only actually get 80Ah.

A 100Ah lithium battery should be able to provide 50 amps continuous for 2 hrs and each cell still remain above 3v while under load. This is called a C2 load rating, a battery with a C20 load rating will not deliver 50 amps for 2 hrs, many will not deliver 50 amps at any time period, the BMS will not allow that much current draw.

The high end price allows access directly to the cells, you can test, and if needed, replace a single cell, or charge a single cell, or clean the links between the cells. They will last 10yrs or more, that is the experience we have with the Winston cells we use and we have used hundreds if not thousands of these cells over the last 11 yrs building off grid power systems.

We get a lot of the lower price end drop in batteries brought in to see if we can fix them, and even some rather high priced drop in batteries. None have ever delivered the capacity marked on the case tested at 2C, some simply won't deliver 50 amps or accept a charge at 50 amps.

T1 Terry
T1 Lithium

[davil]

found this article

think may help when looking for "low end batteries cost, suppliers like Ampere Time with thousands of units sold could not stay in business if their products have a liability/legal actions track record.

==========================================

chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/https://www.wilsonelser.com/files/repository/PL_eNews0308_LithiumIonBatteries.pdf
=========================================

"The rise in alleged lithium and Li-ion battery failures in the past few years is undoubtedly due to a combination of factors: the increase in numbers of batteries in the marketplace; media/Internet accounts of alleged failures; recalls and public perception; higher energy batteries; and new or inexperienced manufacturers trying to get a piece of the pie. While manufacturers continue to research and develop the next new technology, the products of today have become reliant upon rechargeable lithium-ion batteries as power sources. As manufacturers and the CPSC continue to issue recalls, the media, the plaintiff’s bar and their experts will continue to implicate these batteries as ignition sources. Given that the number of these claims will only increase before they decrease, it is in the product manufacturer’s and battery supplier’s best interests to quickly and thoroughly investigate each incident and protect themselves from these claims. Over time, if the manufacturers and suppliers are consistently able to disprove any causal link between the battery and the ensuing fire or injury, claimants will think twice about pursuing these types of claims."
============================================

[davil]

refreshing my questions

trying to explain the reasons for price disparity.

Quality of product, such as cells not properly secured, protected and separated inside box.

Type, not all use same technology, been the preferred Prismatic vs Cylindrical.

BMS crucial element and a weak point on lower end prices.(this issue nicely covered)

thanks

David

[CarlF]

I’ve been running a bank of five 300AH Kilovaults for over a year now. These were recommended by Rod. Couldn’t be happier. If you go with drop-ins these are things to think about in selecting from the many brands:

1. The Kilovault BMS is far more robust than most - 200amp continuous discharge, 150amp standard charge rate (200 amp max). With five of these batteries in parallel I never come close to these limits.

2. Kilovault specs a low absorption voltage (14.1v). This is much easier on the cells than pushing them to 14.4v. Unlike most drop ins, Kilovault’s BMS balances at 14.0v.

3. Use equal length cables. Kilovault requires equal length cables for parallel wired batteries so they charge and discharge at equal rates. Due to the low internal resistance of lithium batteries batteries if you wire them like AGM banks with a positive cable at one end and negative at the other the lithium batteries will frequently be at very different states of charge.

4) Warranty - one of the reasons for much cheaper brands on Amazon is that the company may have only been around a year and will be gone in another year. The warranty is of no value - so the batteries can be sold for less. Kilovault is backed up by 20 year old solar company AltE so the 7 year warranty means something.

[newhaul]

Originally Posted by davil

My intention is to open a thread dedicated ONLY to LOW END PRICED Batteries

Please, limit postings to the stated heading.
Be specific to brands or types.

There are many threads dedicated to different aspects of LiFePO4 installation and technical considerations, more than 1000 postings!

My goal is to find answers to the following questions

What makes prices so widely different, with extremes from a few hundred dollars ($ 370) to over ($ 1000) for a common 100AH unit.

Have spent considerable time on Google, Brand sites,Rod's comprehensive review (Marine How)

Looked at customer reviews on Amazon for different brands.

The usual answer "you get what you pay for" does not necessarily provide logical explanations.

Depending on type of sailing, cruising, variables such as charging and monitor systems not all owners have the same needs and perhaps installing the top of the line may be an overkill IF having facts to make an informed decision.

Findings

These are some of the points that try to explain the reasons for price disparity.

Quality of product, such as cells not properly secured, protected and separated inside box.

Type, not all use same technology, been the preferred Prismatic vs Cylindrical.

BMS crucial element and a weak point on lower end prices.

Amazon listing over 4000 reviews with each one purchasing more than one battery brings a possible usage of 10000? units? with mostly positive experiences.

As reference, these are some of the more rated/purchased brands

CHINS LiFePO4 Battery 12V 100AH Lithium Battery - Built-in 100A BMS,

Ampere Time LiFePO4 Deep Cycle Battery 12V 100Ah with Built-in 100A BMS

There is only one way to get high quality with low price. It's called DIY bank .
I have A grade aluminum case CALB 250ah cells and a 200 amp single in single out Daly bms with active top balance. Just under $700

[T1 Terry]

As you say, cell security and the quality of the BMS are issues, but actual quality and cell capacity are also serious issues .... issues unfortunately hidden inside a drop in sealed top battery.
Relying on a reseller of cheap products to tell the truth, or even know the truth or just what the truth would look like, is a very risky business.
Cell security and just what is in there can only be verified by removing the top of a sealed drop in battery .... then the basic, you open it, you own it applies, so maybe buying a single cheap battery and testing it, removing the top and seeing just what is in there is a way of knowing what you bought ..... there is a person on You Tube, Will Prowse

https://www.youtube.com/watch?v=RxMIs0PXrBw

worth watching this video.

The first thing that I see is neither battery shows the individual cell voltages, so you simply rely on the BMS to get it right
The second thing, how does the BMS cool itself? The cell balancer is part of the BMS so it is important to know what type of balancer is used.
The most common and cheapest is resistance type balancing. At a certain voltage the resistor is turned on and it uses up some of the stored energy in that cell. Resistors burning off electrical energy create heat. The balancer show has big heatsinks so ....

The other type are active balancer BMS modules, mostly because of the price they generally aren't used in a drop in battery ....and second the size.
Quality active balancers use induction coils, cheaper ones use capacitors. the difference, capacitors leak and fail over time, the quality generally dictates the time to failure and naturally, the cheaper the shorter the expected life cycle.
Induction coils are just that, a wire coil that gets powered up to the cell voltage, then the connection to the cell is cut and all the coils are joined together, the voltage equalises across the coils, then they connect back to the cell. If the voltage in the coil is high than the cell, then it dumps capacity into the cell until the voltage equalises, if the voltage in the coil is less than the voltage in the cell, capacity is drawn out of the cell to charge up the coil .... then the whole process repeats, just at a very fast rate. The induction coil doesn't wear out and the switching is electronic components ... there is always a weak point but as these things are mounted in resin, their life cycle is long.

A the short version, resistor type balancers can only drain cells, they drain very little current so they are relatively useless for an active system. They need to be cooled or they heat up the inside of the battery case and that damages the cells over time.
Active balancers move capacity from the high cell to the low cell, so even if each unit only moves the same amount of capacity from the high cells to the low cell, 3 high voltage cell and 1 low voltage cell, the balance is 3 times faster .... and there is little heat involved, always some heat because nothing is 100% perfect, but not enough to be an issue.
The user needs to know what the voltage of each cell is so they can judge if there is a problem that needs attention.

A quality battery will have the BMS separate from the cells.

In both of the batteries tested, the BMS could be separated from the battery to allow cooling.
As can be seen, the drop in batteries tested are just cells in a box, the extra money is in paying someone to build the box and bolt the parts in.
The wiring for the cell voltage measurement is a simple JST - XH 5 wire plug, look on evilbay and they are cheap as chips to get extensions etc. Add something like this https://www.ebay.com.au/itm/28406896...Cclp%3A2047675
but look in any model shop site and you will find plenty.

So, why not build your own and save $$, get a quality battery at a budget price that you understand how it all works, because you built it, so you can fault find and fix as required.


Just a note on the "Big Battery" Will stripped down to show what was inside, the cells are lying on there side. Will didn't pick up on this, but that will seriously reduce the cell capacity over roughly a 6 mth period ... why, all the electrolyte drains to one half of the cell leaving the top half of the plates dry .... no electrolyte, no lithium ion transfer so no capacity in the half of each cell. Stand them on their edge or their base, don't lay them on their side. Only applicable to prismatic cells, cylindrical cells only have the active and the passive plate all wound up inside, so the activity between the plates moves the electrolyte around the plate surface.

T1 Terry

[Nic Homan]

A friend of mine has taken the time to research and build his own 1000Ah battery array from the individual components. He has saved himself a small fortune unlike myself who bought an expensive ready made but bullet proof system. The internals are almost identical in both systems.

[argonauta1]

Keep it simple and inexpensive: 6 volt golf cart batteries connected in series/parallel as necessary I found is the best way to go.

[JBP]

Originally Posted by Nic Homan

A friend of mine has taken the time to research and build his own 1000Ah battery array from the individual components. He has saved himself a small fortune unlike myself who bought an expensive ready made but bullet proof system. The internals are almost identical in both systems.

What were the actual costs? An Ampere Time 100Ah battery is $400 dollars, a Battle Born 100Ah is $900. How much would it cost to build your own 100Ah battery (not all of us need 1,000 Ah).

[Painless]

Originally Posted by JBP

There is a guy on You Tube who dissects all sorts of lithium batteries to see how good they really are.

DIY Solar with Will Prowse
https://www.youtube.com/c/WillProwse/videos

I also think Will Prowse has the best reviews on all things battery and solar.

[Jweyndling]

I installed 3 200Ah Ampere Time batteries in my catamaran 18 months ago. They have robust high quality cases and have performed really well. Time will tell how long they last but so far so good. One thing is that you cannot charge them when the temperature is below freezing.

[Phil_Fr17]

Originally Posted by Painless

I also think Will Prowse has the best reviews on all things battery and solar.

He is more wall-system or back-up system battery oriented than nautical, I find, and sometimes nice or too cool in his reviews. Boating does not suffer from about, in my opinion. Security is at this price.

Originally Posted by Jweyndling

One thing is that you cannot charge them when the temperature is below freezing.

I bet they're not Winston's! Sorry, I didn't understand that "Time" was the brand.
Nevertheless, rare are the LFPs which accept a charge by negative temperature.
"The price is forgotten, the quality remains..."

[JBP]

Originally Posted by Jweyndling

One thing is that you cannot charge them when the temperature is below freezing.

You can get them in self-heating versions that have an internal heater. When you try to charge them below freezing, they first heat themselves up. Both Battle Born and Ampere Time have self heating options.

[Phil_Fr17]

@JBP, interesting... It may be possible for Jweyndling, depending on his technical or DIY level, to dismantle the envelope and add thin sheet heating, much like in yogurt makers.
An idea like that by the way. I don't know if he lives in a cold or hot country.