There are Batteries, batteries and batteries

[beavercreek]

I have been doing some research on what is the best type of battery to use in my next set of large diesels locos to be converted to have the option of being winter battery runners.
My locos also have to climb a very steep incline so will be drawing a pretty high amperage when dragging a train up the slope. So the added weight of a trailing battery car is not best solution.
As I want to fit the cell-packs into the hoods of diesels I concentrated on comparing AA sized cell-packs to deliver 19.2V (16 cells) at about 2600mAH (real life delivery power). These conclusions would also go for 14.4V packs (12 cells).

I have spoken with a few hobby battery retailers including the excellent 'Component-Shop.co.uk'.
This is what I have been told by the guys who know a bit.
NO AA sized nimH cell can deliver what Chinese importers are claiming 3000 -3600mAH)...some even go as far as claiming 4000mAH. This is just hype and hot air.

As I want to fit the cell-packs into the hoods of diesels I concentrated on comparing AA sized cell-packs to deliver 19.2V (16 cells) at about 2600mAH (real life delivery power). These conclusions would also go for 14.4V packs (12 cells).

NiCad...
Good and strong with good amp delivery but can have memory effect if not treated properly. Holds its charge fairly well

NiMh non-LSD..
Better than Nicad for putting up with charging abuse but..self-discharges quicker and can have problems delivering continual high amp output such as that needed by USAT /ARISTO dual power block locos under load.This can lead to shorter running times
Is best for low amp power blocks like those in LGB locos or some other manufacturers where a 14.4V pack can give a good couple of hours running.
SUB-C size cells give better performance as they have larger charge capability

NimH LSD (low self discharge)
Holds charge very well but has problems delivering high amp output for continual use (even worse than non-LSD NimH type).
They do need a long time to recharge if they have been drained (could be up to 32 hours!) and cannot be fast charged.
Again SUB C cell size would be better

Lithium chemistry
When I asked about Li-ion, Li-Po and Li Fe I got some interesting replies, especially from retailers who specialise in Aero and car racing applications (including Component-Shop)
All LI chemistry batteries are capable of fast discharge at high amps but also able to give continual delivery of our G scale 'normal' amp consumption.
They are light in weight and smaller than comparable power NimH/NiCad
But they do need protection during charging and discharging
Nearly all of the Li-packs advertised for hobby use are supplied to the aero.racing fraternity and do not have protection circuits to prevent over charging or discharging.

Li-ion...
Nearly all of the Li-packs advertised for hobby use are supplied to the aero.racing fraternity and do not have protection circuits to prevent over charging or discharging.
There has been a very good thread on this forum about Li-ion by Peter (whatlep) http://www.gscalecentral.net/Lithiu...ata-on-shelflife-and-discharge-rates-m165095. < Link To http://www.forum.gscalece...ge-rates-m165095. This examines some batteries from ebay which DO have protection circuitry

I have a couple of Aristocraft 22V LI-Ion packs that just have the two wires for charging and for discharging as they have the built in protection circuitry. I would like to have more of thebut they are not cheap

Li-Po...
Even lighter than Li-Ion with even more power handling But......
If a Li-Po battery is allowed to drop below 3v and then charged it is then that there could be definite possibilities of fire.
For G scale purposes where the battery may be inside the loco or inside a trailing car, there needs to be some definite way of protecting the battery as even an audible alarm for over discharge might get missed.

Lead acid
Strong, very resilient unless totally discharged, good power delivery. But very heavy and to deliver 14 tp 18 v the size would just be too large.

My conclusions for what I might use are.....
For NimH
SUb-C cell NimH packs (possibly LSD type) would be ideal if there was room inside the loco (a good long hooded diesel). Remember I am really thinking here of USAT/ARISTO large diesel motor blocks. LGB ones would be quite happy with the lower mAH AA size celled packs.

For Li-Ion
Not so volitile as Li-po. A little more forgiving but still has to be treated right with protection circuitry. As I already have a couple then it makes sense.

It will be excellent to hear other member's views and experiences.
If you have views totally at odds with this, it would be great if you gave reasons as I am open to change me mind.
Remember I am talking about USAT/ARISTO dual bogie locos with higher current usage, as opposed to locos with lower voltage and current needs that would be totally fine with 12v to 14.4v AA packs.

 

[Neil Robinson]

That's pretty much the same as I've discovered through research and/or personal experience.
At the risk of stating the obvious the matter doesn't end with the choice of battery type.
Take NiMH AA cells for example. There seems to be a great variety of brand names and prices with varying reputations for lifespan and quality control with the more expensive not always better.
If in doubt go for a supplier who will give good advice and after sales service.
Another vote for Component Shop.

 

[stockers]

Also, the recent changes in postal regulations make it technically impossible to have cheap Chinese batteries mailed in. It is now forbidden to mail Li batteries (presumably because if their fire risk.)

 

[CoggesRailway]

That write up is a good reflection of my learning too.

AA cells marketed/registered in the EU have more stringent rules around the claimed rating. I too have spoken with trusted RC types who say anything north of around 2200mah is just hogwash/contrived and wont deliver in real life. So imports from the web or in model shops from china be realistic. Or beleive the lower rates of the bigger brands.

I, where room allows, standardise on nimh sub c.

An observation- easy to get hung on run time. In practice two hours is more than needed and we are not an RC "session" based hobby, or competitive. So we have plenty of charge time. If u convert to locos I find iam cold/bored before I have nothing to run in winter. With nimh and a good charger u can easily replinish one before the other is done!

Even a big us loco with smoke and sound, is not pulling high performance plane/car amps and u will get decent runs from most chemistries.

 

[Tony Walsham]

AA size. All of them have a "choke" built in that limits the current drain. Anything more than 1/2 an amp will reduce the life span, in terms of the number of recharges.

NiMH. They all self discharge at a prodigious rate. Usually flat in 30 days. Each time that happens it reduces the total number of recharges by one.
They have half the total number of recharges compared to NiCd.
NiMh-LSD originally developed by Sanyo for use in digital cameras, where it was always a pain to go to use such cameras and the batteries would be flat. They too are limited in current draw. 2,200 mah is about right. Designed for a low current draw for a long time. Not high draw for a short time. Sure they will allow high draw but doing so will damage them and reduce the total number of recharges.
Ni-Cd. Not readily available nowadays but the best value for money bar none. Whilst the memory effect is not a myth it has basically been eliminated by the use of smart chargers. Most of which can handle multiple chemistries.
Sub-C not all Sub-C Ni-Cd cells are the same. They have to be marked SCR to handle high current draw capabilities. Non SCR Sub-C cells are generally OK for our usages.

Sanyo make the best Ni-Cd, NiMh and NiMh-LSD batteries.
Always use a good quality smart charger.

Can't comment about Li-xx based chemistries, other than to say I am am always wary of what vested interest claim to be "the latest and greatest". Although I freely acknowledge Li-xx batteries will have to be the battery of choice for very small locos. Just be really careful with them.

 

[beavercreek]

AA size. All of them have a "choke" built in that limits the current drain. Anything more than 1/2 an amp will reduce the life span, in terms of the number of recharges.

Does this mean 1/2 amp form a pack of cells or from an individual cell?

Ni-Cd. Not readily available nowadays but the best value for money bar none. Whilst the memory effect is not a myth it has basically been eliminated by the use of smart chargers. Most of which can handle multiple chemistries.
Sub-C not all Sub-C Ni-Cd cells are the same. They have to be marked SCR to handle high current draw capabilities. Non SCR Sub-C cells are generally OK for our usages.

The problem seems to be that NiCd AA cells come with a max of 1000mAH. So a pack of 16 to give 19.2V would probably not last very long in the diesels that I wish to use them in as in my first post. I really need a minimum of 2000mAH or more. Sub-C sized NiCd cells are better but I have just checked and It looks like 16 of those are not going to fit in (maybe 12 might to give 14.4v)

 

[tramcar trev]

Very interesting.
Nimh Ltd cells I have chosen to make up the battery pack for my prepackaged tv unit. Noah cells have no float voltage when charging which can make charging tricky. I have tried charging 10 cells in series as a 12v 2300mag battery and that worked well enough on 13.5v @ 230 ma. If I discover that individual cells die then they are cheap enough to replace.

 

[CoggesRailway]

Mike, 14.4v will be sufficient to give the running speed u need. If want I can do a youtube of various running 14.4v. Its fast on a garden railway.

Or watch that connie rescue again. Theg are 7.2v running 75% speed. Obviously that varies loco to loco. But that would be bachman 45 tonner at 6v. So u dont need the volts you think.....

 

[Madman]

These are my main batteries of choice. It's what I use to power my locos. They have overcharge and discharge protection built in.

http://www.all-battery.com/li-ion18650148v4400mahpcbpreotectedrechargeablebatterywithbareleads

 

[beavercreek]

Mike, 14.4v will be sufficient to give the running speed u need. If want I can do a youtube of various running 14.4v. Its fast on a garden railway.
. So u dont need the volts you think.....

I was thinking along the same line but for my very heavy inclines (10%+ in places ) and the need for a lot of grunt to get up them, I was also thinking that I will probably need the mAH and the voltage to overcome them (volts x amps for power etc ).
I don't run trains fast but I do like to run long trains at times. Although I won't be using smoke units on the diesels, (Aristo: SD45, GP40, USAT: SD50 (converted from SD70), SD70, GP30, GP38, F3), I will be using sound and lights.
The locos would also be in consists so this might help the individual power consumption as each loco would be taking its own proportion of the strain.
Obviously the power needed for the extremes of my layout will sap a battery much faster than when running on the layouts like you lucky fellows have, with gentle or no inclines at all.

The battery-ised locos will very probably be used, not only in winter, but all year round, so they will need to have the reserve to run for longer periods than the length of time that it takes for me to become numb with the cold. Even in winter I would let them run and control from the conservatory when I went blue. :

So that is why I was thinking of 19.2V NiMH AA packs, as they would give a little more power to be available especially as the battery was becoming drained.

I am definitely in a quandry here....perhaps the Li-ion batteries that 'Madman' mentions (I think they are the same that Peter 'Whatlep' did a very good write-up on) could also be the ones of choice as they could be cheaper options than buying more of the two old Aristocraft Li-Ion batteries that I already have.

If I go with the NiMH packs...
Bearing in mind the eccentricities of my layout, the length of trains, the grunt of the diesels and the prolonged running times that I seek, do I need the extra headroom of 19.2V packs?
Would NiMH be disappointing? Would Li-ion batteries that include the protection circuitry be a better bet, even if they are more expensive?

Mmmmmm..... anyone else out there, with a ridiculous layout, who runs big diesels and long trains with battery?

 

[Tony Walsham]

Forget about AA's.They are choke limited to about 1/2 amp. Each or in a series pack doesn't matter.

14.4 volts is not enough to power those big 6 axle USAT and AristoCraft locos pulling moderately heavy trains.
18 volts of heavy duty Gel cells would actually work quite well. They are awkward to fit in anything and doing so would likely require quite substantial body and chassis modifications to them in.
Use Sub C's at a minimum. and don't believe the mah rating on them either unless they are Sanyo cells. I would use two x 8 cell packs in series to get 19.2 volts. Finding a smart charger that can handle 16 cells is not easy and they are more expensive than the more common max 15 cell chargers.
To increase the run time put two 16 cell groups in parallel with a diode on each 16 cell group to protect from one set of 16 cells back feeding into the others. The diodes also ensure the control system draws equally from each bank.
You would charge each bank of 16 cells separately. You should be able to get four 8 x cell packs inside the body shell of an SD70 etc.
There is no low cost way of doing this.

 

[Mij]

Guess my torch batteries will not cut it then:clown::clown:

 

[stockers]

These Chinese BLUE batteries (or any LITH) are banned by Honk Kong postal authorities. Not sure about mainland China (they'll probably ignore the ban)

Quite correct Ross. The ban is also by most postal services including the UK. IATA regulations on the movement of small quantities make air transport almost impossible. They are a class 9 hazardous material and the labelling and paperwork is onerous - to say the least. The shipper is legally responsible. DHLs guidance runs to 27 pages and thats just a preci of the regulations - in short - you cant mail these Li batteries.

 

[beavercreek]

:thinking:On the other hand Boeing Deamliners use Lithiums Mmmmmmm....

As does every laptop, mobile phone, tablet etc that travels inside planes........of course you can't charge them.....unless you are in business/club/first class........it is always the rich who sink the poor ..............

Thanks for your input Tony.
Well it seems to come down to Sub-c packs or the Aristocraft 22v Li-ion jobbies for the big diesels. Two 8 cell Sub-C packs will be a tight fit, even in the larger diesels but as 'Component-shop' (and I should imagine other suppliers too) can make 'custom' configurations it is going to be a case of taking some exact measurements I think.
I have an Anselm Xmove quad 'smart' charger so will check to see what the cell limit is for that one.
Are diodes needed for two 8 cell packs if they are going to be charged as one?

 

[stockers]

They probably work on the basis that if your jobbie catches fire on your lap or in your back pocket you might notice it.!nphone:

 

[Neil Robinson]

Two 8 cell Sub-C packs will be a tight fit, even in the larger diesels but as 'Component-shop' (and I should imagine other suppliers too) can make 'custom' configurations it is going to be a case of taking some exact measurements I think.

2/3 and 4/5 sub-C size cells used to be available in NiCd.
If the site link below is to be believed 4/5 are currently available in both NiCd and NiMH types. Naturally the run time between charges will be lower than full size sub-Cs. The reduction in physical size may however make possible fitting them inside the loco.

http://www.batteriesplus.co.uk/acatalog/Batteries_Plus_Tagged_Batteries_26.html

 

[CoggesRailway]

I know there are loads of people who "know best" about this topic. However i run heavy trains with batteries so it may be worth listening, even though i am no chemist. U do need to forget AA. Please watch this all the way through. Nothing more than single pack 14.4v nimh sub c. The alco pulled this for over two hours. The drag on the drawbar was huge - I pulled it my self by hand to see!

I guess the key is get the most umph you can for the physical space- and invest the money to buy good quality/capability.

I have also found diode protected paralell packs a good solution, simple to do.

http://www.youtube.com/watch?v=xQoHGmmid44

 

[beavercreek]

whoops

 

[Tony Walsham]

Diodes are only necessary if the packs are to be used in parallel. That is, increasing the capacity or run time.
They are not used when battery packs are placed in series. That is, increasing the voltage.
What voltage to be used is a subjective thing.
The more voltage, the faster the loco will run.
My suggestion would be to run the loco on track power up to the maximum speed you desire. Measure the voltage going to the track, add about 1 volt and you have the ideal battery voltage.
As a rough guide the 22 v Lithium packs will result in slot train speeds unless the voltage from the Lithiums sags under load.
14.4 volts is just fine for most locos.
14.4 volts is also fine for LGB locos when the ESC motor driver output is wired directly to the motors. If an LGB loco has the 6 volt lighting circuit no motion will happen until after the lights and sound come on. Then you need to add 6 volts to allow for that.
14.4 volts would work if you are happy with slow to medium speeds on the big 6 axle locos you have mentioned.

 

[beavercreek]

I know there are loads of people who "know best" about this topic. However i run heavy trains with batteries so it may be worth listening, even though i am no chemist. U do need to forget AA. Please watch this all the way through. Nothing more than single pack 14.4v nimh sub c. The alco pulled this for over two hours. The drag on the drawbar was huge - I pulled it my self by hand to see!

I guess the key is get the most umph you can for the physical space- and invest the money to buy good quality/capability.

I have also found diode protected paralell packs a good solution, simple to do.

http://www.youtube.com/watch?v=xQoHGmmid44

Due to the power hungry nature of the USAT/ARISTO large diesels, I have cast AA sized cells aside and am concentrating on the maximum number of SUB-c sized cells that In can fit into the hoods alongside Aristo Revo boards, sound board etc.
I have not discarded the use of fully protected Li-Ion packs like the Aristo ones as they pack the power for smaller space.... BUT one thing that I was told by the aero/racing fraternity was that Lithium chemistry does hate the cold and that if I store the locos (with the batteries inside) in a cold environment (which they will be) the Li-Ion packs will not work optimally.

So I thanks all you lads greatly and also to the advice from the good trustworthy retailers.
Small locos...AA NiMH or small protected Li-ion
Large power hungry locos.... SUB-c NiMH or larger protected LI-ion
If size of void in loco is a problem then Li-Ion
If no problem with void size, then SUB-c as they are a lot cheaper! (they also have one more advantage..they add more weight for traction)

I will go for the 19.6V option as, although i do not run fast trains, I do have to climb large inclines and will need to drive the locos harder. DCC boards have back-emf but Aristo Revolution boards do not.