Battery Comparison for 48V off grid system

[Gullo]

Hi guys.
I have an enormous system - but I didn't start this way. I built\building it bit by bit in 3 stages. I have one piece of advice about batteries - and the system as a whole. Buy modular and scalable and field servicible equipment!!! And I mean it. Buy equipment that is designed to work together - and I don't mean proprietary... I mean modularly. I cannot possibly stress this enough! These projects are so expensive, and they only get worse if you don't plan open-ended.
To that end, I suggest only one battery, the Discover 42-48-6650. This Battery just works! It communicates with your solar equipment. It's configurable. It's expandable. The service is fantastic! And most of all it has a fantastic cost of ownership.
They're pricey on the front end, but if you shop around, you'll find them cheaper than MSRP. But what makes them affordable is that they're so easily expandable. You can buy some and then buy more later (not too much later - If you understand batteries, you know why). I personally purchased 7 and then upgraded to 13 and then 17, and they seamlessly connected to my system with no preparation required.
I know the battery nerds out there are reading this and want me to address why.... it's because each unit has its own very robust bms, AND those bms's communicate with one another over a bus, so the units can be "installed" with all different states of charge without risking the cell Imbalancing associated with trying to expand prismatic cell packs.
For fellow intermediate users, prismatic cell packs have a common bms, and even with cell board cards and balance boosters installed, when adding cells, you need to Disassemble the pack entirely and configure the cells in parallel to top balance the old cells and the added cells. Then the cells need to be reconfigured in the compound 48v topography.... basically they're a pain in the neck to increase capacity!!!
No matter how detailed your load calculations are, once you've owned your system, YOU WILL WANT MORE BATTERY CAPACITY. It's almost guaranteed. The Discover batteries are so simple to expand - no matter if you use them as an SLA replacement or as a pack with a combiner box, when you want more storage, you hook them up to the pack and voila! They will balance and equalize on their own. If you tried that with a prismatic pack, it would be an absolute nightmare! I know it because I've been there.
There are dozens of other features and benefits to the Discover battery but their website can cover those. I'll finish by comparing these to the simplifi and the others.... The Discover battery actually provides the whole 6650 wH. The other so-called SLA replacement LiFePo4 batteries only support approximately 80% of nameplate capacity. The LG and Simplifi and Smart and of their cheaply constructed brethren - especially all of those prismatic cell manufacturers - all advertise a capacity, but only allow the batteries to be discharged to a significantly lower capacity - 80% max DOD is common.
MOREOVER, none of them have a communicating bms, which SIGNIFICANTLY increases the charge voltage. Discover bulk and absorb voltage on their communicating battery is 56.7V compared to as little as 52V for the others.
Seriously, this battery kicks butt! And if you shop around, it could actually come to you cheaper than the MSRP for the cheapest of its competitors. I shopped around and got them very affordably (about 20% more than the prismatic cells)...

[Mike90250]

semanticas Karrak
When I say batteries, I meant CELLS All the companies you listed buy cells from somewhere and assemble them into batteries.

Tesla buys CELLS and assembles them into a battery, with an integrated BMS and several pages of excluded coverage. As Sunking said, they don't make cells, panasonic makes them, and somebody else (Billys outback battery service) takes cells and bolts them together into a battery.

[Sunking]

Are those Vendor warranties, or battery Mfg warranty ? Vendor or Integrator warranties are next to useless, they are not likely to be around to honor them, but great if they do.
Battery Mfg's would have the expertise and actuarial data to warranty the batteries.

Mike you and I know Karrak is full of it. Example I know exactly what cell is in the Powerwall 2. It is the exact same cell used in the current Model 2 from Tesla. They both use a Panasonic NCR18650B cell which is the absolute best LCO cell made. Don't take my word for it, go look for yourself Pansonic claims 500 cycles period. 10 years my arse. You would have to be a fool to believe 10 years.

[karrak]

Here is a list of lithium batteries with 10 year manufacturers warranties. This is in Australia.
LG Chem Resu10
SimpliPhi PHI3.4
SunGrow SBP4K8
Delta Hybrid E5
Elmofo ECells
Arasol neeoQube
Ampetrus super lithium
BYD B-Box LV
DCS PV5.0
Solax 3.3
BMZ ESS3.0
Tesla Powerwall 2
Solar Watt MyReserve
Trinibass Powercube
Solarwatt MyReserve
Hansol AIO 10.8
Enphase AC battery
Magellan HESS
Sunverge SIS
Alpha-ESS ECOS5

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

[Mike90250]

.... Or how about the 10 year warranties offered by many serious suppliers of lithium ion battery systems?...

Are those Vendor warranties, or battery Mfg warranty ? Vendor or Integrator warranties are next to useless, they are not likely to be around to honor them, but great if they do.
Battery Mfg's would have the expertise and actuarial data to warranty the batteries.

If the battery mfg gives a 4 year warranty, and installer Joe says he will warranty it for 6 years, do you see the disconnect ?

[SunEagle]

You are right that only a small % of systems with LA batteries will only ever reach an 8 year life span. We are not talking about LA batteries we are talking about lithium ion batteries.

If you want more evidence go to the Energy Matters forum. Or how about the 10 year warranties offered by many serious suppliers of lithium ion battery systems?

What about the naysayers that constantly make statements that are very economical with the truth?

As I said open forums allow people to post just about anything without hard scientific evidence to back up the claims.

I am open to the possibility that LI chemistry batteries have long lives and can be deeply cycled. But in the hands of most people, a home grown battery system won't last long because they do not know how to properly design them or take care of them.

Maybe if someone comes up with an off the shelf big box store "LI battery system" that is cheap and easy to maintain a homeowner will be able to claim long life and all the power they want. But I have not seen that product here in the US yet.

[karrak]

While some people may be able to generate power for a long time and get many cycles out of their batteries, I would say it is only a small % that will ever reach an 8 year life span with their batteries.

On top of that it is easy to make a statement in an open forum without needing to provide the facts to back it up.

I am not saying you or "steveg" are not telling the truth but a number of people come here and do like to embellish the "facts".

You are right that only a small % of systems with LA batteries will only ever reach an 8 year life span. We are not talking about LA batteries we are talking about lithium ion batteries.

If you want more evidence go to the Energy Matters forum. Or how about the 10 year warranties offered by many serious suppliers of lithium ion battery systems?

What about the naysayers that constantly make statements without any evidence to back them up and that are very economical with the truth?

[SunEagle]

As usual you are not reading what the OP said. The OP said he has 14 panels (probably around 300W ea) and was looking at at the 9.5kWh LG battery or the 10.5kWh Panasonic battery




Please explain how steveg manages to use about the same amount of power each day with his LFP battery based off grid system as the OP intends to and that it nearly 8 years old? This post gives details about his system and its performance.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

While some people may be able to generate power for a long time and get many cycles out of their batteries, I would say it is only a small % that will ever reach an 8 year life span with their batteries.

On top of that it is easy to make a statement in an open forum without needing to provide the facts to back it up.

I am not saying you or "steveg" are not telling the truth but a number of people come here and do like to embellish the "facts".

[karrak]

To start with there is no such thing as 9.5 kWh of panels. I assume you mean 9500 watts of solar panels aka 9.5 Kw based on 14 Panasonic or LG panels. 9500 watts on a off-grid battery system is a huge system that is going to require two very expensive 80 amp charge controllers operating into a 48 volt battery. 24 volts 4 controllers and 12 volts if you are a fool will be 8 controllers.

As usual you are not reading what the OP said. The OP said he has 14 panels (probably around 300W ea) and was looking at at the 9.5kWh LG battery or the 10.5kWh Panasonic battery

That would mean you use 390 kWh / 30 days = 13 Kwh each day. That is an insane amount of power for a battery system. To do that with FLA batteries requires a $13,000, 4000 pound battery you will be replacing every 5 years. Use LFP and you are looking at a $18,000, 2000 pound battery you replace every 3 to 4 years.

Please explain how steveg manages to use about the same amount of power each day with his LFP battery based off grid system as the OP intends to and that it nearly 8 years old? This post gives details about his system and its performance.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

[Sunking]

I am designing my own solar system right now and will use either the 9.5 kwh LG Chem Li-ion battery or the Pika energy island with 10.5 kwh.
To me those batteries have the longest warranty and the most discharge charge cycles.
I have 14 panels Panasonic or LG.
What are the expert thinking about this ???
Greetings, Harold

First you are hijacking someone else thread.

To start with there is no such thing as 9.5 kWh of panels. I assume you mean 9500 watts of solar panels aka 9.5 Kw based on 14 Panasonic or LG panels. 9500 watts on a off-grid battery system is a huge system that is going to require two very expensive 80 amp charge controllers operating into a 48 volt battery. 24 volts 4 controllers and 12 volts if you are a fool will be 8 controllers.

Selecting Lithium batteries is the exact opposite of what you asked for. The longest warranty and cycles are Flooded Lead Acid batteries at 1/3 the cost.

Lastly there is this..

Average monthly use is 390KWH

That would mean you use 390 kWh / 30 days = 13 Kwh each day. That is an insane amount of power for a battery system. To do that with FLA batteries requires a $13,000, 4000 pound battery you will be replacing every 5 years. Use LFP and you are looking at a $18,000, 2000 pound battery you replace every 3 to 4 years.

[hbrand]

What are your loads ? (itemized in watt hours, please)

Average monthly use is 390KWH

[Mike90250]

This is Harold.
I am designing my own solar system right now and will use either the 9.5 kwh LG Chem Li-ion battery or the Pika energy island with 10.5 kwh.
To me those batteries have the longest warranty and the most discharge charge cycles.
I have 14 panels Panasonic or LG.
What are the expert thinking about this ???
Greetings, Harold

What are your loads ? (itemized in watt hours, please)

[hbrand]

This is Harold.
I am designing my own solar system right now and will use either the 9.5 kwh LG Chem Li-ion battery or the Pika energy island with 10.5 kwh.
To me those batteries have the longest warranty and the most discharge charge cycles.
I have 14 panels Panasonic or LG.
What are the expert thinking about this ???
Greetings, Harold

[Sunking]

I have started a new thread looking at this topic.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller

You must like getting beat up.

[karrak]

I never said you cannot parallel them, I said you WOULD NOT WANT to parallel them. Big difference. If you parallel any modular battery (more than 1-cell in series), does not matter what type, you are going to significantly shorten cycle life. Proven fact Jack.

I have started a new thread looking at this topic.

Simon

Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries installed April 2013
BMS - Homemade Battery logger github.com/simat/BatteryMonitor/wiki
Latronics 4kW Inverter, homemade MPPT controller