Electric vehicles-Conversions

[bobins]

I had a few rides on this, maybe ten years ago on my first visit to Santa Barbara.

http://www.santabarbaracarfree.org/how- ... us-around/

That got me wondering how many trolleybus services are in use - I reckoned they can't be that popular due to the infrastructure needed. How wrong could I be !!!

"Currently, around 300 trolleybus systems are in operation, in cities and towns in 43 countries. Altogether, more than 800 trolleybus systems have existed, but not more than about 400 concurrently."

From Wikipedia https://en.wikipedia.org/wiki/Trolleybus

I've only ever been on one and that was down in (I think) Sevastopol. It didn't cost us anything to use as the ticket collector didn't want to try to communicate with us

[bobins]

Do I presume that large battery banks are "wet" alkaline?. The term "large" would then be very relevant .

Some of the installations I've seen could be described as very wet ! Nothing more than open containers of acid with the plates dangling in them...... and these were military grade installations...... Though I hasten to add that these weren't Western military sites

[Peter.N.]

We had trams and trolleybuses in my youth, the trolleys need less infrastructure but are less efficient than trams. I like them both, we go for a ride round Beamish most years.

We have a 2/3 scale tramway at Seaton but when we took the grandkids on it I thought I was buying shares in the company rather than a ticket.

Peter

[CitroJim]

Do I presume that large battery banks are "wet" alkaline?. The term "large" would then be very relevant .

The ones I dealt with driving a big building UPS years ago were were two banks of lead-acid cells in glass containers delivering 440V each at several hundred amps... They could support the full building critical load for around 30 minutes...

We had two banks of these and they occupied a very large tiled well-ventilated room. One of my jobs (when it was my turn) was to check the specific gravity of each cell and top them up as required....

That was a long and tedious task...

[harryp]

Remember travelling on trolley buses as a child in Rochester/Chatham area, would have been sometime about 1946-8 . Also remember seeing one with the arm off the wire; apparently a very common occurance.
Jim the Alkaline battery's were a very different kettle of fish; very corrosive electrolyte and with a very low internal resistance - you didn't dare short them out The upside was that you could run them flat without damage and when charging they would take all an alternator could throw at them until 80% full, when the charge would begin to taper off. I once acquired an ex bus one which at 25AH was more than sufficient to start the bus! I would think that it would probably melt a battery cable rather than just get it hot! On its way to me in the boot of a friends Mini it fell forward and the terminals punched 2 holes in the rear seat back where they touched ; spot welding, almost

[CitroJim]

Indeed Harry, a very different kettle of fish! I've only had experience with small alkaline batteries - used as battery backup in remote repeater stations - but even those required careful handling...

I've seen too what a short across HP2 (D Cell) sized Ni-Cd batteries could do... Quite impressive and a very serious fire risk.

A standard automotive lead-acid battery can be pretty lively if short-circuited too

[Peter.N.]

Harry

I remember NiFe batteries from my youth, they made one with a bank of small cells with a switch running down the centre which would switch the cells in series - parallel, it was used for a radio HT supply but could be recharged from a low voltage.

Excellent batteries if weight is not an issue as they are almost indestructible. I see someone has started making them again but they are very expensive.

I remember trams and trolley busses from Kent where I was born and bred, not all that far from Chatham.

Peter

[bobins]

I know where there's two banks of Alcad alkaline wet cell batteries for starting two Rolls gensets. The batteries must be way over 20 years old and still giving faultless service. It seems to be one of the Alcad batteries strong points - its long service life.

[CitroJim]

I remember NiFe batteries

Ahh, that's it I was struggling to remember their name... Although it refers to their plate materials it became their eponym in the same way as Hoover became the name of all vacuum cleaners...

Many people called them 'Knife Batteries' and spelled it that was in written notes too...

Here's a Wikipedia article on them...

As you say Bobins, extremely tough and durable which is why they were so good in unattended relay stations that received a maintenance visit once in a blue moon...

[white exec]

When I was teaching (some physics) during the '70s, a local authority science adviser came up with the money-saving idea of switching school laboratory student experimental kits on to rechargeable NiCd HP2s, instead of the shed-loads of normal zinc carbon HP2s then in use.

All went well, for a few weeks, until the reports of mishaps with short-circuits - melted wires, destroyed rheostats, burns... IIRC, the NiCd's were well capable of a good many amps when short-circuited, something which school students are adept at. The dry cells made a come-back; I think 1A was all they were good for.

[NewcastleFalcon]

More general information here on composite flywheels, and a summary of the state of play at the time, 2014 as it happens so not right up to date.

Plenty of input from Williams of F1 fame and also reference to a pioneering Buckinghamshire firm Urenco:!:

http://www.compositesworld.com/blog/pos ... g-up-speed

Regards Neil

[bobins]

Plenty of input from Williams of F1 fame and also reference to a pioneering Buckinghamshire firm Urenco

Regards Neil

To start with I thought "That can't be the same company as..........." Then a few seconds later the penny dropped -> Urenco -> Uranium enrichment -> centrifuges. Ah !

[NewcastleFalcon]

Plenty of input from Williams of F1 fame and also reference to a pioneering Buckinghamshire firm Urenco

Regards Neil

To start with I thought "That can't be the same company as..........." Then a few seconds later the penny dropped -> Urenco -> Uranium enrichment -> centrifuges. Ah !

Yes I looked Urenco up after I picked it up from the article, bit of a sideline from their main business.

But does give a location of Stoke Poges for the head office.......quaint!

Regards Neil

[bobins]

That's actually a fascinating article, Neil. Thanks for finding it.
There's a paragraph in their that puts the Urenco connection into perspective:

"According to WHP director Patrick Head, there are 500,000 composite centrifuge rotors (used for enriching uranium) that have been operating 24/7 for 20 years. (Note: a quick analysis of Urenco enrichment facilities estimates 575,000 centrifuges in operation by 2020.) According to an in-house strategy document, Urenco claims, “Another huge strength that Urenco has is their centrifuge technology that runs for 35 years while competitors have to replace their machines every 12 to 15 years.”

And a note to CitroJim - as well as the Culham facility that you really ought to book a tour on, you should also get on a tour of Urenco's facility at Capenhurst. A very fascinating - if somewhat eye-opening - few hours to be spent there. Their evacuation procedures if one particular alarm sounded makes you sit up and take note - it was akin to (and I paraphrase here) "Run away, very fast, climb over bodies if you need to"

[NewcastleFalcon]

Today's little slightly off-topic diversion heads off to California, and a rapidly implemented project involving the construction of the world's largest lithium ion battery storage facility, to make better use of the generation of electricity via solar power within the "grid".

Story here

http://www.utilitydive.com/news/inside- ... ci/431765/

Using a battery to meet demand peaks means it will likely be fully charged and discharged nearly every day. That puts a lot of strain on lithium batteries, which degrade as they get older and are cycled more often.

Under SDG&E’s contract, AES must maintain the batteries’ nameplate capacity and performance for 10 years, after which the utility takes responsibility for the project. Typically this is done two ways — by oversizing a battery project upfront or by adding new cells during operation to support capacity.

Follows on from Southern California Edison awarding Tesla contracts to supply 20 MW (80 MWh) of lithium ion battery storage capacity at the utility's Mira Loma substation near San Bernardino, California.

Unlike the Renault , "We are a car maker not a chemist" quote earlier in the thread, TESLA do have wider ambitions

http://www.utilitydive.com/news/sce-tap ... ho/426471/

Regards Neil