BYD BBox

Getting into the nuts and bolts of wind and solar power components, installation and performance issues, ask technical questions, answers and tips

Re: BYD BBox

Postby tom rickard » Sat Mar 04, 2017 12:12 pm

I'm more interested in anyone with first hand experience of the different construction / chemical makeup of competing LiFePO4 LFP cells.

At this stage, especially for off-grid where the batteries are the primary energy source, it's a big risk to go for a powerwall, or Zcell, where it's as likely as not that the companies won't even exist in a few years time.

The next 5 years will tell if the LGResu / Samsung / Sony, etc with the LiNMC chemistry can last the distance in the Aussie heat. If they can, then that will be the way to go. In the meantime, i'll stick with the LiFePO4's. Just need to get more information so I can work out which type of LiFePO4 cell is the best value.
tom rickard
Solar Evangelist
Solar Evangelist
 
Posts: 92
Joined: Tue Nov 26, 2013 3:32 pm

Re: BYD BBox

Postby australsolarier » Sat Mar 04, 2017 12:18 pm

well, we will wait 5 years and will have more information then.
australsolarier
Solar Crusader
Solar Crusader
 
Posts: 279
Joined: Sun Mar 28, 2010 10:27 am

Re: BYD BBox

Postby Gordon-Loomberah » Sat Mar 04, 2017 12:51 pm

My CALBs will have been in use for 5 years in 9 months time. Apart from one cell with reduced capacity (retired from use last year, but I'll probably pair it up with the next weakest cell at some stage), the battery is still performing well, generally at >50% DOD each night these days. I work them pretty hard, often using 40-45kWh per day in warm-hot weather, and the nominal battery capacity is ~21kWh, although no doubt it is slightly less now.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia

Re: BYD BBox

Postby jaahn » Sat Mar 04, 2017 1:37 pm

Gordon-Loomberah wrote:My CALBs will have been in use for 5 years in 9 months time.--- I work them pretty hard, ---often using 40-45kWh per day in warm-hot weather, the nominal battery capacity is ~21kWh,---

Hi Gordon :)
Would that first statement actually mean 4 and a quarter years ?? :P
You are certainly using them hard, 200% is extremely hard some would say :shock:
Thanks for sharing your experiences. :mrgreen:
Jaahn
jaahn
Solar Crusader
Solar Crusader
 
Posts: 126
Joined: Sun Apr 25, 2010 9:42 am

Re: BYD BBox

Postby Gordon-Loomberah » Sat Mar 04, 2017 2:18 pm

Yes indeed 4 1/4 years, but since 5 years was the magic number in the previous 2 posts, my point was I'll be there in 9 months :)
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia

Re: BYD BBox

Postby offgridQLD » Sat Mar 04, 2017 7:10 pm

10 years is my magic number for many things to represent good value.

my electric car is a 2012 so cells are 5 years old . 16kwh bank that I have seen 63kw discharge and 45kw recharge (regen) often using 80% of the capacity and all 88 cells always recharge at the top to within 5mv.

I guess my point is that good cells can give incredible performance for many years. I will see how they are in another 5 years a the ten year mark.

I do actually have some (about 50 cells) 10ah capacity Headway lifep04 that are now 9 years old. performance is still very good for the age, partially if they were being used for a stationary storage application at low discharge rates they are able to put out close to there nominal capacity still.

In the real world there is only one way to test things and that just takes time............
Offgrid 2008, Selectronic PS1 6kw/48v inverter, x 2 Midnite solar classic 150 MPPT, 3960w NE PV 24 x 165w BP panels, 4200w NW PV 21 x 200w DAQO PV, 16x400ah lithium.
offgridQLD
Solar Crusader
Solar Crusader
 
Posts: 2067
Joined: Thu Jan 26, 2012 12:50 pm

Re: BYD BBox

Postby offgridQLD » Sun Mar 05, 2017 2:12 pm

I just dug up the original shipping docket from china for my headway lifepo4 cells (dated October 2008)
8 years 5 months old cells.

I few weeks back I pulled 9.2AH (measured from shunt based energy meter) from a 10ah 24v bank powering my Electric kayak.

They have a little more voltage sag under high load than years ago but its kind of making me question calendar life theory's.
Offgrid 2008, Selectronic PS1 6kw/48v inverter, x 2 Midnite solar classic 150 MPPT, 3960w NE PV 24 x 165w BP panels, 4200w NW PV 21 x 200w DAQO PV, 16x400ah lithium.
offgridQLD
Solar Crusader
Solar Crusader
 
Posts: 2067
Joined: Thu Jan 26, 2012 12:50 pm

Re: BYD BBox

Postby tom rickard » Sun Mar 05, 2017 4:29 pm

I guess life vs price is where it is at for me. I don't mind paying 1/3 the price for something that lasts 1/2 as long..

My point on the LiFePO4's is that they have been in many off-grid installations for 5 years + now, and those that have been treated sensibly are still going strong. I'd say they have proved themselves fit for that application.

The LiNMC packs are still at the 0-5 year stage for the ones that I know of, so it won't be long before a meaningful comparison can be made.

From my view, there is still no clear stand-out battery when it comes to off-grid storage, even the newer LA cells still have their place in my opinion. It really depends on the individual application.

It would be nice if there was more information out there, but I guess it's just such a small niche market that no-one really cares too much.
tom rickard
Solar Evangelist
Solar Evangelist
 
Posts: 92
Joined: Tue Nov 26, 2013 3:32 pm

Re: BYD BBox

Postby australsolarier » Sun Mar 05, 2017 5:08 pm

the most economical experience is always that experience that somebody else did. it does not cost you any money, nor wasting 5 years waiting. you only have to listen. there are always those people, when you tell them "do not touch this terminal because it has 450 volts on it" they instantly have the need to touch it to see if it is really true or see what happens when they do.

so, there are more than a million electric cars on the roads. one guess what battery technology they use? and what did they find out about keeping the battery cool? about balancing the cells? not over charging nor over discharge. etc.

the matter of the price, i think lifepo4's and lithium ion are still the cheapest for their life span and discharge cycles and charge and discharge capacity. for me it is a no brainer really.

lithium battery technology took 20 years to develop until they were first commercialized in small appliances. they have come down in price since then more than ten fold. and they have been in commercial use almost 30 years since.
the question is not what battery technology, but which lithium technology you want to settle on.
the battery management in cars cost more money than the actual battery itself. that is why you want to settle on the reliable manufacturer, that takes pride and knowledge in the battery management. that is why tesla and other car manufacturers get the batteries from china, korea and then make the battery management system themselves.
my main reasons being on the fora here is not so much giving my 2 cents worth, but to read what other people write about their experiences. that is for example why i have an aircon in the elektro shed. i prefer it this way, not having to shorten the battery life just for the sake of my own experience. i am totally happy somebody else reduced capacitiy to 60% in their RV. (they have since moved the lifepo4 into the interior of the RV)
australsolarier
Solar Crusader
Solar Crusader
 
Posts: 279
Joined: Sun Mar 28, 2010 10:27 am

Re: BYD BBox

Postby tom rickard » Sun Mar 05, 2017 9:13 pm

Not all of the EV battery experience is transferrable to using the same chemistry cells in an off-grid house power application. Certainly a lot can be gleaned though.

Still doesn't answer my question about the different manufacturers of LiFePO4 cells, and exactly what different manufacturing techniques they use, and how to determine the quality of the cell other than to wait until there are enough of them out there to get a decent answer.

No EV (commercial) that I know of uses LiFePO4 cells, so not much commercial information / experience available.

As you said, plenty on the LiNMC, but for a house bank the jury is out on how slow charge rates affect the durability. It's difficult to control the charge regime when it is cloudy! EV's have more easily controlled charge / discharge regimes.
tom rickard
Solar Evangelist
Solar Evangelist
 
Posts: 92
Joined: Tue Nov 26, 2013 3:32 pm

PreviousNext

Return to Components, Installation And Performance

Who is online

Users browsing this forum: Bing [Bot] and 7 guests

new solar power specials