Vanadium batteries, a lithium-ion alternative ?

[Lance]

Vanadium batteries become option for solar home owners looking at lithium-ion alternatives.

A new use for the metal vanadium — better known for its steel-making qualities — is emerging as energy savvy consumers continue to look for better ways of storing solar power.

http://www.abc.net.au/news/2016-12-08/v ... ge/8094376

[T1 Terry]

We had a salesman for Redflow masquerading as a technical adviser give a lecture at the last Electric Vehicle convention I attended a mth or so back. Like this article, it was very selective on the down side facts The next day we got to have a face to face talk with their installer and a lot of the stuff that was left out was now supplied.
They are less than 80% efficient on the fully cycle from in and out again due to the parasitic pump losses. They must be fully discharged every 4 days from memory to strip off the metal build up on the active material. This means double the size battery is required because every 2 days one of the batteries must be completely discharged. If that charge is transferred to the other battery then a second 20% plus loss is involved.
The 20 yr life is the max for the cells themselves, not the electrolyte, that must be replaced depending on the number of cycles and remember that every second cycle is a 100% discharge, so no partial cycling like lithium. The cost is quite a bit more than LiFeP04 and each unit is huge, their comparison to an outside air con unit must be one for a very big house The electronics and special inverters to go with these batteries aren't cheap either.
This technology has been recycled every 5yrs or so since 1985, it wasn't competitive with lead acid batteries back then, not in the running against lithium batteries no matter how much they try to twist facts 5 to 8 yrs for lithium and 20 yrs for a redox flow cell, these guys should be selling used cars

T1 Terry

[native pepper]

My 120amp portable lifepo4 pack is 8 years old, used every day, with no lose of capacity and can be carried around easily.

[BruceS]

120amp or 120Ah? Yep, I know what you mean!

[native pepper]

Sadly Bruce, yet to be able to work out the difference between amp hours and amps. Have this maths mental block, which really frustrates others when I'm trying to describe something electrical. Thanks for your understanding.

[T1 Terry]

A few negatives I forgot yesterday, they can not be moved or suffer any vibration when operating, so a concrete slab is required, but they are that heavy a concrete base would be required anyway.
They are temperature sensitive, if the electrolyte reaches 60*C to whole thing shuts down, I believe the current rating in or out start to taper off at around 40*C, so the outback property relying on these batteries for all it's power would need an insulated and air conditioned battery shed.
Having said that, if the ambient temp was much more than 50*C any battery and associated electronics would need some form of cooling besides air movement.
Lithium batteries will release the most energy at around 60*C, the drag racers actually heat their battery packs, but for long service life they should remain below 40*C. Most inverters start to throw in the towel at 40*C, there are few exceptions, so an ambient temp below 40*C shouldn't require any additions for cooling other than air movement, but even if it was to hold up around the 40*C in the battery shed I'd think some form of addition cooling might be a good idea.

T1 Terry

[supersparky]

Gee, we are going back to the dark ages now aren't we. Sheds, cooling systems, concrete slabs etc. That's what the old LA batteries banks used to require. I thought that we were in the 21st century now.

[BernieQ2]

If they can from japan they would only require Tatami Mats .
Bernie .

[T1 Terry]

Gee, we are going back to the dark ages now aren't we. Sheds, cooling systems, concrete slabs etc. That's what the old LA batteries banks used to require. I thought that we were in the 21st century now.

At least the fumes from LiFe cells don't have to be vented outside and your clothes don't dissolve in the new wash after a specific gravity test, so we have at least moved that far forward
I don't think Elon Musk and his team have considered the higher ambient temp in Aust, or maybe that is why it's intended to be installed inside the house, to gain the benefits from the air con
With small inverter split system air con being so cheap and frugal on energy requirements, a few extra panels would keep the battery enclosure cool. LiFe are light enough to use a container as the battery shed so only the wooden floor already there is needed, but concrete foundations with container locks would be a good idea to keep it from floating away in some areas, that includes the type of float dragged by a semi