Life of Lithium Ion 100aH 48V battery packs and sales techniques

richardimorse

The latest sales pitch I heard is that these batteries last 1 million cycles which is 2750 years, the electron was identified 120 years ago so I guess we have come a long way.  But seriously how scalable is this technology if I want a 48 kWH battery bank can I do it with 10 stackable units and will it expand to 20 units.

Does anyone have experience sizing at 80% DoD I don't think anyone implements at 80% that is too empty bucket the next morning for my liking, I can see 60% being quite common or even 70% but not 80% because their is no spare capacity

Dave Angelini

Thats funny stuff, where have you been getting that line?

There are quite a few projects running now in this state doing exactly what you describe but at higher voltage for utilities.
For 48v the web store here has some that will go up there. Maybe not 20 units but quite a few.

Why would you want to wire all of those batteries? To me the advantage of going to L-ion is using around 10kwh packs and limiting the wiring. Also using an internal designed in BMS and a company that will be there. Not so easy to do yet but I have a few.

jonr

The future is fully integrated packs with built-in BMS and providing the voltage you want.  Preferably with a warranty from a reputable company.

I don't know what to make of the 100% DOD (probably BMS limited, not the actual cell DOD) and 10,000 cycle claims/warranty that one sees here:

https://www.solar-electric.com/simpliphi-phi-3-5kwh-48v-lithium-ferro-phosphate-battery.html

About $600/year for 7kWh/day ($.22/kWh if you throw it away at 10 years, $.08 if you did 10,000 cycles)

Dave Angelini

The future is here. Schneider allows the BMS to alter LBCO in their inverters to get down to close to zero Dod. Of course if you turn on large loads at a low battery Soc you are asking for lights out. The BMS also does limit Dod to be able to stay powered up waiting for the charge source to come back, even if the inverter has shut down.

A good battery system should have the shunt for state of charge built in. That is the main reason I don't get excited about batteries like Sympliphi. They need an external shunt to communicate Soc to the user.
Maybe they will fix that and make a bigger battery

There are BMS strategies for taking multiple battery banks down and saving one battery for the last. A spare but a very expensive one.

Still around 1K$ US for a KWH.   Still see 99% Sol on mine after 2 years of heavy cycling.

richardimorse

Well done got it in one again @Dave Angelini

Lithium BMS is a major issue, it is like will my cell phone support IOS 12, they are a locked pair, the battery and the management system and as technology moves along . . . which battery packs can connect to which BMS versions and which upgrades are required . . . been there before with Unix Operating system upgrades causing comms cards to stop working due to firmware and having to line up the database versions and realising that I can't use the new Unix hardware and hence have a major problem.

So buying Lithium BMS means buying from a company that is going to minimise this pain for you and be there in the long term.
I guess simpliphipower is a good bet . . . only time will tell if you have to go to the after market for your upgrades

I think someone misread the 10,000 cycles and started saying 1,000,000 cycles so the upgrades only have to remain available for 27 years
 

Ampster

richardimorse said:

.......
Lithium BMS is a major issue, it is like will my cell phone support IOS 12, they are a locked pair, the battery and the management system and as technology moves along . . . which battery packs can connect to which BMS versions and which upgrades are required . . . been there before with Unix Operating system upgrades causing comms cards to stop working due to firmware and having to line up the database versions and realising that I can't use the new Unix hardware and hence have a major problem.
.............
 

I dont agree that Lithium BMS is a major issue. I think the assembly of prismatics in to packs of 48 volts is pretty simple for most people that have assembled a LA battery pack.  There are several BMS's for 16 cells (48 volts). Many of them uses a simple windows interface. In the case of the Orion Jr which I have been using for 3 years I can change the parameters as I change chemistry. Originally I was using it on some large 160 Amphour prismatic LiFePOs. Latter I changed to cells from a Nissan Leaf. Each of those chemistries has a different minimum and maximum voltage and the BMS was easy to reprogram. That included changing the number of the cells because the LFPs needed 16 cell groups in parallel and the Nissan Leaf Modules only needed 14 cells to get the same pack voltage. 

A custom pack of Lithium prismatics is almost infinitely scalable because no change in BMS is needed and an increase in size only means more cells in parallel. The big advantage of this approach is cost. Lithium prismatics can be found for under $500 per kiloWatthour.  I like this approach because I save money and have more data about how my pack is doing than I would with higher priced solutions like SimpliPhi. 

Dave Angelini

Simplyphi is not ready for prime because of the lack of internal Soc data for sure.

It does take a knowledgeable user to DIY this safely. Most of my clients could or would never be able to implement and safely make this work over time.

Most all of the DIY LFP look at bit dangerous also, at least the ones I have seen. An insurance inspection would probably not like seeing anything like I have seen. Certainly not anywhere in a home or attached garage. They need to be in steel or aluminum enclosures with tamper proof security.

Raj174

Dave Angelini said:

Simplyphi is not ready for prime because of the lack of internal Soc data for sure.

It does take a knowledgeable user to DIY this safely. Most of my clients could or would never be able to implement and safely make this work over time.

Most all of the DIY LFP look at bit dangerous also, at least the ones I have seen. An insurance inspection would probably not like seeing anything like I have seen. Certainly not anywhere in a home or attached garage. They need to be in steel or aluminum enclosures with tamper proof security.

They are dangerous, I dropped one of my 195AH Hi Power cells on my foot once and at 13 lbs, I thought, now that's gonna leave a mark. 

Rick

Dave Angelini

Put ice on it every hour for 15 minutes

richardimorse

We have a new startup company in South Africa making these, they are not cheap at $420 per kWh Capacity, customers are listening to snake oil salespeople who tell them everything is infinite and better, even lead carbon has a hard time competing, not technically, but in terms of the packaging and commodity status, where the battery tells the charge controller what to do over canbus.

Before you had Tradesmen selling inverters with car batteries, now they sell inverters with these batteries, they do a complete botch job on the electrics and walk away, solar is now being sold and installed by people who sell and install air conditioners, so no need for solar experts anymore ?

Dave Angelini

I can imagine it. The worst thing about what you said is a start-up. Sell as much as you can and then go out of business.  Then the BMS gets hit with lightning and you have a new failure point that was not there before with old technology.

I really totally love the LG RESU that powers my offgrid home so do not get me wrong please. It comes with all of the safety certifications, the testing for failure, and a very respected company. I just wish I could by them in NA.