Lead acid vs lithium long term stationary storage

[byteharmony]

I'm looking at storing stationary power for a long time. Is lead acid serviceable battery power smarter than lithium?

What is the Maintenance lead acid
- add distilled water: yearly
- desulfite:?
- venting hydrogen?
- keeping at a specific temperature?


anything else?

Lithium
- temperature control

What's a good choice for very large batteries, 100kwh 48v Nominal

Thx

 

[time2roll]

I would be in lithium.

 

[Rednecktek]

LFP can pretty much just sit there forever. You may have to build/buy spmething to wake them up though.

 

[cs1234]

If you want to have something to do, a 100kwh lead acid battery bank sounds like a time consuming hobby.

 

[MurphyGuy]

Lead acid is a horrible standby battery.. they need to be exercised in order to maximize lifespan.

The best solution would be an over-sized lithium battery stored at about 80% SOC in a semi-refrigerated environment. If you could size the battery bank so that an 80% charge would do the job you need, and keep the battery bank in the lower 40 degreeF range, the thing would probably last 20+ years.

I think the king of emergency energy storage is a fuel cell.. pretty much indefinite.

Or maybe a propane generator with a fogged cylinder.

 

[Samsonite801]

Both options still have a measurable self-discharge rate, don't forget to take that into consideration. They need to be checked on once in awhile to see where they sit at... They can't just sit there for 20 years and expect to stay charged forever without some form of maintenance charging.

Lead acid need floating or they go flat pretty quick, as lead acid have a much worse self-discharge rate, and round-trip efficiency (like I've heard 80%), compared to their LFP counterpart (up to 99% round-trip efficiency), with much lower self-discharge rate.

lifepo4 self-discharge rate - Google Search

 

[byteharmony]

Oh dear, I can see long term may have been construed as holding the same charge a long time.

I should have said flexed over a long period of time. As in cycled daily for years.

 

[Samsonite801]

Oh dear, I can see long term may have been construed as holding the same charge a long time.

I should have said flexed over a long period of time. As in cycled daily for years.

Hmm, thanks for clarifying... Well it's no secret that LFP have more expected cycles in them and more years life expectancy (they usually say anywhere from 3000-5000 cycles, although who's tested that, and 10 years lifespan)..

The limitation on temperature is that you cannot charge them below freezing (can still discharge them below freezing, although they will still lose some efficiency as the temps go down colder like lead batteries do)...

The life of lead acid can really depend on how well they are cared for, the plates sulfate over time, and require equalization charging periodically to help keep the plates cleaner to help them achieve maximum life.

 

[Ampster]

I think the king of emergency energy storage is a fuel cell.. pretty much indefinite.

A fuel cell is a source of energy using fuel. It is not storage. In fact all fuel cell vehicles that need any acceleration, need batteries to buffer the slow response time of fuel cells for acceleration of the vehicle.

 

[MurphyGuy]

A fuel cell is a source of energy using fuel. It is not storage. In fact all fuel cell vehicles that need any acceleration, need batteries to buffer the slow response time of fuel cells for acceleration of the vehicle.

I know, but a fuel cell can provide energy and its fuel can generally be stored forever.

Vehicle acceleration? I was under the impression the op was just looking for an emergency battery that could store energy until needed.

 

[Ampster]

I know, but a fuel cell can provide energy and its fuel can generally be stored forever.

Okay, I see where you are coming from. Storing fuel and storing energy are different things in my mind. I understand fuel is stored energy. People also refer to oil in the ground as stored solar energy from many years ago. I am not trying to change your mind. My comment was for the benefit of other readers who may not understand the nuance.

Vehicle acceleration? I was under the impression the op was just looking for an emergency battery that could store energy until needed.

My example was to explain the use of batteries as storage versus the consumption of fuel in a fuel cell. Some would argue that it is not even consumption, it is a change in form of energy.

 

[DIYrich]

ZBM3 Battery – Redflow

redflow.com

 

[Ampster]

ZBM3 Battery – Redflow

redflow.com

Yes, flow batteries are really a combination of processes. If I understand most of them correctly, the fuel is inexpensive. Topping off PB batteries with water could be another example, which gets us back to the title of this thread.
With effective recycling of Lithium batteries, one could argue that the components are fuel that is consumed over the long term. It all depends on where you are standing.

 

[MurphyGuy]

Okay, I see where you are coming from. Storing fuel and storing energy are different things in my mind. I understand fuel is stored energy. People also refer to oil in the ground as stored solar energy from many years ago. I am not trying to change your mind. My comment was for the benefit of other readers who may not understand the nuance.

My example was to explain the use of batteries as storage versus the consumption of fuel in a fuel cell.

Hey man, technically speaking, coal and oil are both organic.. ROFLMAO

Yeah, I was just speaking about a solution to having something like a very long term energy source in storage. Pretty much any fuel in a pressurized cylinder and the appropriate hardware to turn it into electricity would work. IE: Generator+ propane or fuel cell + whatever gas it's designed for.

Fuel cells are pretty expensive, was throwing it in to make a point. Propane + generator is probably the most practical and economical.

 

[Ampster]

And I would argue that Lithium is the better long term storage compared to Pb. At least that is the conclusion reached by people building utility scale battery storage. I have noticed that recent solar farm construction has also included battery storage. Economics is probably the driver of those decisions.