Battery types and suppliers

[MikeWilliams]

Can somebody please direct me to somewhere I can read about battery types, sizes, output and how to look after them?

Having recently acquired two battery locos and with two more on the workbench, the technology is new to me and I need to learn fast.

I know there are now several types including the old acid, Nicad, lithium and maybe others too, and I'd like to read about their attributes and suitability for Gauge 3.   Are some motors more suitable for batteries than others - coreless for example which draw less current?

Or, is there anyone on here who feels able to write such a summary?

Thanks,

Mike

[John Candy]

Mike,

My own personal view is that Ni-MH are the best for our type of application.
The Lithium types have a lot of power for their size/weight but durability is an issue.

They begin to deteriorate the moment they leave the production line and continue to do so (whether or not they are used). They have 'shelf life' and an 'old stock' battery bought new could well be on its way out!

About 2 to 3 years ago I bought a 21.5 v lithium pack (from GRS) and left it in the cupboard until recently. When I came to charge it, it would only charge to 15V.

I read up on lithium batteries and they apparently have useful life of around 3 years, regardless of how they are treated, it has something to do with oxidation of the metals.

I saved the info on my computer (somewhere!) and will email it when I find it.

Regards,
John.

[John Candy]

Mike,

This is the link to the lithium battery article.

http://www.batteryuniversity.com/parttwo-34.htm

John

[MikeWilliams]

Thanks John.  You have confirmed what I suspected.  Is there a web site/supplier you would recommend with a large range of Ni-MH batteries, so I can find one to squeeze into the side tanks of my loco?

Mike

[John Candy]

Mike,

Brian Jones makes up packs to fit whatever space you have available (they come ready 'shrink-wrapped' with connecting leads).
He uses 'Strikalite' cells http://www.strikalite.co.uk/ and they are a very helpful company (you will remember my battery charging problem which resulted in a safety-related discussion on this forum).

Regards,
John.

[cabbage]

(cough!)

Mike,

Please consult "Batteries.doc" in the submissions area for articles for "The Technical Manual" -then look at the "Technobots" website.

regards

ralph

ADMINISTRATOR'S NOTE : Before anyone asks, 'where do I download the Technical Manual articles?', the answer is you cannot!
The Technical Manual is a proposed publication under consideration by the Committee of the Society and will not be generally available for some time yet. Only the Committee members have access to the webserver directory which contains the submissons which will not be released until vetted and approved as being appropriate and containing 'safe' advice. John Candy

[MikeWilliams]

Thanks both.  Have now read all that and looked at the web sites.

The loco I have was built 17 years ago with two lead/acid batteries, each of 12V 7Ah.  There is a change-over switch so they can be connected in series or in parallel, thus providing 12V or 24V to the huge traction motor whose make and type are unknown.  There is also a variable resistance so the speed can be controlled.

I guess technology has moved on since those days and I am just wondering about replacing those batteries (which are in a coupled but separate van), with new technology in the loco.  Any clues as to roughly what sort of space equivalent Ni-MH batteries would take up?  I'd like a rough idea whether its feasible before contacting somebody like Brian, and his web site is quite brief on batteries.  Technobots list lots of things but not really what I want.

Thanks,

Mike

[John Candy]

Mike,

The AA size cells are 1.2V 2400mAh and can be arranged in a pattern to suit the available space.
If you want 24v you will need 20 cells which could be two packs of 10 each, perhaps  one in each side tank?
The packs will be quite heavy and if all on the same side, the loco might sit awkwardly in a lop-sided fashion!
The 12 (4x3) pack in my N5 bunker has it 'down' on the back springs and I have had to counter-balance with weight in the smokebox!

Assuming you have the loco at Ampthill today, we can take some measurements.

Regards,
John.

[cabbage]

OW!

If you have a motor with a need for a (Potential) 12V 14Ah supply then it might not be possible to get it to use NiMH or NiCd batteries. It sounds like it could be a series wound one (possibly 3 or 5 pole). Try and get some dimensions on it and (if possible) count the number of poles that the motor has -slowly rotate the motor and feel for the commutators then divide by 2.

It might be possible to fit "slim line" 6V 1.3Ah SLA into side tanks -consult the MAPLINS website for those.

regards

ralph

[IanT]

As a lateral thought Mike, why not change the motor? It should be easy to get a modern motor that is smaller and consumes a lot less power. It probably just needs some form of motor plate 'adaptor' - to match the new motor spindle to the existing gearbox.

Regards,

Ian T

[Moonraker]

For a motor like that you need to be using a pack of Sub-C batteries not AA. My GRS Pannier runs for a bit more than 2 hours on each charge. I use two model racing car battery packs (7.2 volts each) wired in series.

Peter

[Christopher]

Try this

http://www.batteryuniversity.com/index.htm