Should I bet on the near future of battery technology?

I need to purchase a new 48 volt battery bank. Intend to buy 8, 6-volt batteries in the 350ah range. If quality and longevity were my highest priority (which they might be) I'd buy Rolls. But my question is this: Given the blazing pace of change in battery technology, would it be smarter to go with the cheapest possible solution that'll get me through a couple years, on the assumption that at that point there will almost certainly be more cost-effective options.
Just interested to know people's thoughts.
Just interested to know people's thoughts.
Comments
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
I am available for custom hardware/firmware development
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
Lithium batteries are gaining momentum as you read this and they are being applied to RV/marine/solar systems daily. The existing sales are largely driven by the promise of more deep cycles and less weight in the case of mobile applications. Some sales literature will quote superior charge/discharge rates and wider temperature tolerance, but that is already available with some lead-acid designs.
Once we see field verified applications prove that they really will perform long term...... per the marketing projections/estimates, the world will come running.
In the mean time, biting the bullet to invest 3-5 times the capital outlay to reap the rewards later - requires a certain leap of faith. Feel free to climb out on the "bleeding edge of technology" and let us know how you are doing in a few years!
Don't forget to include the cost of that invested capital.........
Marc
thoughts?
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
The expansion angle is interesting, but I guess if we separated charge control down to the cell level we could add to lead banks as well.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
The RESU 10 will support 5kw continuous and 7 kw peak but if the second bank is less KWH, it will have less continuous and peak output.
http://members.sti.net/offgridsolar/
E-mail [email protected]
You were thinking of buying a Rolls bank. That means you aren't going to get generic golf-cart cells from them. With LFP, you don't know, unless you do your homework and DEMAND that your supplier reveal that along with the cell-specs to you. Some assume you are too dumb as a consumer to know the difference between crap LFP cells and good ones anyway, so there is no point telling you or peeling back the re-wrapping of cells.
With large-capacity prismatics, you know what you are getting, just like with lead-acid for the most part. With full specs. Hey, just like lead acid. But in today's world, unless you DIY it yourself, you are at the whim of the purchasing department.
The reality for the future is everyone is looking to make a way to hide the technology inside from the consumer, and eventually proprietize the connectors, internals and charging systems and play the patent-troll sue-ball game.
Lead-acid is basically an "open system", with a century or more of basic tech behind. Not too much is proprietary. You can still slap some clamps on a lead-acid and charge. With lithium magic-boxes, (unless you know what you are doing) heh, no chance.
Technology early birds always seem to pay a large premium while often playing the guinea pig role. These claims of 15-20 year lifespans have no real world examples that I know of.
I would currently buy more lead unless weight and charge efficiency was an issue. Lithium should be well "tried and proven" by the time some good deep cycles are ready for recycling.
Now my "Post Comment" box is not working for at least a long minute. Just became useable..... Someone is controlling this board.
BTW you have come to the right place if you need technical questions on your build. There are a number of very knowledgeable members here
From the size of your proposed system you definitely will be in the market some of the larger controllers. There are some pretty sophisticated offerings out there these days. A few of the Mfg. that come to mind would be Midnite Solar, Outback, Schnider/Xantrex and Magnum.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.
Sounds like a good opportunity to learn balancing, charging and other characteristics of LFP batteries.
Might not be a good idea to buy any more solar equipment before you have a plan for a balanced system designed to meet your specific power requirements, designed for the in the area you live in. For example, your choice of 24 cell 320 watt panels will not allow the use of flooded lead acid batteries without the use of a special high VOC CC, as two panels in series will not produce enough voltage and 3 in series will produce a high VOC.
Many people make the mistake of buying the wrong equipment before they have a final design.
Rick
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Just posted here as the discussion was about battery tech, used car batts, and which direction to go. I decided not to go FLA as it is old tech and there are many alternatives at good pricing. With the advent of the number of EV's out there now, there are plenty of opportunities for salvage batteries that will serve our home storage needs quite well. People run into things with their cars just as often in EVs. For example, my 420AH LiFePO4 set cost me $2200. Used, but they will have a gentle remaining life in my garage. I will start a new posting about my project. Thanks
I intended to type 24 volt. To bad they don't make an auto correct for that.
Rick
The OP may have 2 or 3 strings. Winston cells come in sizes of 90, 100, 160, 200, 260, 300, 400 and up to 1000 amp hours.
Rick
Bob
I would be interested to know how old the batteries are and what their internal resistance is now that they have lost around 25% of their capacity, also what the variation in capacity between the the cells is.
You mention 3 strings in your last post. Did you mean wiring 3 cells in parallel and then wiring the 3 cell blocks in series or wiring the 16 cells in series and then wiring the 3 strings in parallel?
Thanks
Simon
32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
modified BMS based on TI bq769x0 cell monitors.
Homemade overall system monitoring and power management https://github.com/simat/BatteryMonitor
Bob