If the price can come down into an affordable range, then they will be fantastic for frequency control of the power grids (regulating power on the grid up and down in the range milliseconds to a few minutes.) and also for un-interruptible power supplies where the need is often to deliver power instantly when the grid goes down and maintain it for a few minutes until standby generators can be started.

If you have a high power intermittent application in a hot desert – where you will be charging and discharging the battery fast, then Lead Acid will have a greatly shortened life – battery life halves for every 11 centigrade above 25C, which gets worse for a battery with poor cycle efficiency as the losses turn into unwanted heat in the battery!

I’m looking at some Trojan T-105 RE lead acid batteries for my off-grid use. They are rated at 1,000 100% DoD cycles. 4,000 20% cycles.

I believe there are lead-acids rated for more cycles, but don’t know the numbers offhand.

If lead-acids weren’t so bulky/heavy a set of REs in a 200 mile range EV would be 160k to 200k mile batteries.

DEEP cycle-life is of paramount importance of EVs/PHEVs and gird energy storage applications. The highest cycle-life requirements are for Wind turbine blade control, frequency adjustment/control on the gird, and regenerative braking for EVs/PHEVs. Supercapacitors can or already are used for the later applications. I’m sure there are other, maybe industrial electric motor power, but I’m not an expert in this area. Supercapacitors are typically higher cost and lower energy density than chemical energy storage batteries (lead-acid, NiMH, Lithium). You still need a chemical energy storage battery to go the distance in an EV or PHEV. Lithium is the best of the three and many lithium ion batteries can provide a lot of power for a short time, so why even add expensive supercapacitors for regenerative braking?

lead-acid something like 20 to 60 deep cycles, maybe more nowadays. I’ve read 700 or 1,500 deep cycles for carbon-lead-acid. I don’t know how much of that is bs/hype.

I have several year old information that says NiMH batteries are about twice the energy density of lead-acid and are good for 500 to 700 DEEP cycles. An order of magnitude better than most lead-acid for cycle-life.

Lithium ion batteries are typically good for several thousand DEEP cycles. (My old table, not updated in a few years, lists 9 lithium ion batteries claiming 3,0000 DEEP cycles or more. Altairnano claimed 85% good after 15,000 DEEP cycles for their Lithium Titanium Oxide batteries. Toshiba has claimed 80% after 6,000 DEEP cycles for their Lithium Titanium Oxide SCiB batteries.) Another order of magnitude better than NiMH batteries. This is why Lithium batteries are predominantly used in EVs and PHEVs.
Bob is correct about Lithium MnO2/Mn2O4 and Lithium FePO4 chemistries being available in addition to Lithium TiO2. There are some others and an awful lot of research in this area right now.
There are even more diverse chemistries being used for lower cost grid storage. For those applications weight and energy density are lower order issues and low cost, determined by including number of DEEP cycles they can be used, is of greatest importance.

Toyota uses NiMH batteries in the Prius because the design is over ten years old and they don’t want to change it. You can get away with this in an HEV because you are just using it for load leveling on the Internal Combustion engine. (ICEs have an efficiency curve with the greatest efficiency at a narrow speed range… Hence the need for complex gears/transmissions. The electric motor/generator in parallel is used to keep the ICE operating at a more optimal speed.) The Prius battery charge controls rarely allow it to come close to full discharge level. My own Prius rarely goes below 1/3 discharged and 2/3 charged. This allows the inferior NiMH chemistry to work for the HEV application, but means you are carrying around a lot of dead weight most of the time.

Toyota bad mouths Lithium battery technology, but they lie. They are trying to make as much profit as possible from the Prius design without changing much. The plug-in Prius uses a lithium ion battery. NiMH would not do the job. The lithium ion in the plug-in Prius does more and is apparently about half the size.

The original EV1 design used lead-acid batteries, but was later improved using NiMH. Now we have EVs that run circles around the EV1 at a fraction of the production cost (order of magnitude lower cost) using Lithium ion batteries. The Nissan Leaf, Ford’s EV, GM’s Spark and Volt, and Tesla Roadster and Tesla Model-S all use Lithium batteries. The Tesla battery is interesting. I believe they use, or maybe originally used, lithium-cobalt which is the “unsafe” lithium chemistry invented in the 1970s. They solved this problem with electronic controls and mechanical isolation. If the individual cell starts to misbehave then it is isolated electronically. If it gets hot and fails by burning up, then it is still isolated mechanically from effecting the other cells. They have not had problems with this design and it allowed them to use low cost cylindrical Lithium batteries made by large companies in the millions for electronics use. Don’t remember if they are moving or have moved to a safer chemistry. Doesn’t matter. It’s already safe. Waaaayyyy safer than gasoline.

I think there was a conspiracy surrounding the NiMH technology originally invented and brought to the market by Energy Conversion Devices. I think there was a semi-successful effort to purchase patents and keep this tech off the market. Ancient history. Multiple lithium chemistries are out there now. They are way better and the future profit potential is greater than what the oil companies can pay to keep it off the market.

Don’t forget DEEP cycle-life is important!

I did find this one comment which I’ll offer because it sounds good. Don’t know how accurate it is…

“NiMH batteries are well known for their fast degradation as cycle count increase. They don’t last as long as the NiCd batteries they replaced, although development have reduced that difference.

NiMH batteries used for hybrid vehicles are a sort of
“heavy duty” NiMH battery, designed to be durable and provide good power. This does however come at a cost, the energy density is not as good as other NiMH batteries. To reduce degradation hybrid cars also keep the batteries state of charge in a narrow range; typically less than half the actual capacity. The result is a poor energy density, only about 30 Wh/kg.

There isn’t one type of lithium ion battery,
there are several different types. The most common are the cobalt oxide, manganese and iron phosphate types. The lithium ion cobalt oxide type provide good energy density, today in excess of 200 Wh/kg (just the cell alone), but they are unstable (safety issue), and they offer a poor power density. When they degrade over time, which is both cycle and age ralated, they lose capacity and the internal resistance increase (the latter will limit power output over time). These batteries are mostly suitable to low power portable devices where maximum battery time is of great importance. But such a battery is not suitable for a production car.

Lithium ion manganese and iron phosphate batteries offer a
higher power, and they are are much more stable (safe). But this comes at the cost of a lower energy density – about 110-140 Wh/kg on a cell level. Power densities can be in excess of 3 kW/kg. To improve battery life, the battery is oversized just as with NiMH. Using half the
capacity we’re down to about 55-70 Wh/kg and for a complete pack about 50 Wh/kg is reasonable; some 60% better than a NiMH pack. Chevrolet Voltfor instance uses a lithium ion manganese spinel battery. These batterytypes are also common in power tools which require durable high power batteries.

Lithium ion have other advantages too. They don’t
require large amounts of nickel which would be problematic for large scale production of batteries, they don’t have a high self discharge andtheir charge/discharge efficiency is very high. The latter means less battery heat during charge/discharge and greater fuel efficiency. NiMH batteries suffer froma particulary high internal resistance when they approach a high state of charge.

Today NiMH batteries are used for two reasons; they are safe and cheap. But NiMH is also a mature technology. This means they batteries are proven, but it also means there isn’t much room for improvement. NiMH are about as good and cheap they can be.

Cobasys did also offer NiMH batteries to the large
car manufacturers, but there wasn’t much interrest after California dropped the demand of zero emissions cars. Electric cars where neither practical or cost effective and it took a great deal of development until Toyota actually made a profit from their hybrids, and these have abattery that can store just slightly more energy than a regular lead acid car battery (at several times the cost). Small electric car
manufacturers never could offer the volumes required to start series production.”

http://www.supercars.net/PitLane?viewThread=y&gID=1&fID=2&tID=183739