Large Scale Central

14.8v or 18.5v for 2-6-0 (B-mann 10 wheeler)

OK so I was poking around and asking about batteries and chargers. I assumed I was going to use 14.8v to run my mogul. When I sent an email to rich at Cordless Renovations and told him what I was looking to power up he recommended 18.5v. I told him I was building a 2-6-0 on a 10 wheeler chassis.

So how many volt to power this loco? for all practical purposes it is still a 10 wheeler in size and weight and number of drivers. I plan to pull 5 or 6 cars along with the tender.

I am getting the hang of this battery thing I think. The original thinking was to start with a 14.8v 2200-2600 mAh pack and then if I needed to add another 14.8v 2200-2600 mAh in parallel to give me 4400-5200 mAh @ 14.8v. Now I am wondering if I need to instead do 18.5v. Space is a consideration as it is all going in the tender along with a speaker and the RC equipment. With the RC equipment installed and leaving room for a sound card that leaves me a space 3 3/4 X 3 X 1 3/4 for batteries and speaker. One thing I am thinking is that I am thinking I need more mAh than I really do. Looking back at the build thread seems people are suggesting 2600 would be enough. I think I would have no problem getting 18.5v in there with a mAh of 2200-2600. One consideration is to run an 11.1 flat pack on top pf the speaker and a 7.4 pack vertically between the speaker and the RC frame work I built. I have included the pictures to show what I am up against.

Cordless Renovations CR-1600B it 14.8v @ 3000Mah it will work just fine. we have them in stock at RLD Hobbies

So playing around a bit I think I have a real possibility here. Realizing that the only difference between 14.8v and 18.5 volt is one cell. Also knowing that the way that you get voltage is by adding cells in series the solution cold be very simple. If I buy 1 14.8v pack (or two 7.4v packs) and decide that it doesn’t work well I can always put in a single 3.7v cell in series. The single thickness packs are about 3/4 of an inch. that only leaves me 1" high for the speaker. If I go with two 7.4v I can put them in there in a tee pee fashion over a taller magnet on the speaker. I can get creative in making the speaker enclosure cone shaped and baffled to get great sound. A 7.4v pack is 2.8 long and an 1 1/2 wide. So they can go one in front of the speaker and one behind leaned inward slightly.

That would give me 14.8v at 2600 mAh. If I had to I am sure I can squeeze in another single cell if I have too.

Devon, maybe if you had run it on track power, you would know how much voltage for the kind of speed you want. My 10 wheeler usually runs at or below 12 volts, and that is plenty fast for mine. I run my shay, climax, and Aristo C16 in the 14 volt range, and I cant say that I run anything in the 18 volt range.

The Bachmann 10 wheeler also doesn’t draw a lot of current. So, I would say that 14.4, or 14.8 volt pack should give you the speed you want. As for MAH, I defer to the experts on that. Since the thing doesn’t draw much, you don’t need a huge battery for the loco. Now the sound board will draw power, and the smoke unit (if used) will suck up a lot of electrons.

David,

Track power was never really a consideration. I have zero intention of having track power, most all of my club is RC and to have built it with power pickups would have to have been deliberate in construction since the driver spacing and chassis is all together different than the 10 Wheeler.

Based on yours and others observation 14.8 will more than suffice.

A few thoughts. First and foremost, there are very few large scale narrow gauge prototype locos on the market which do not run amply fast (if not exceptionally so) on 14 volts. I’m working on two right now which will be running on 11.1 volts. My “standard” pack is a 14.8 volt/2600mAh pack, and most of my decoders have their top speed dialed back to around 60 - 70% of that, even. When “hauling the mail” was done at a breakneck 20 miles per hour, you don’t need a whole lot of voltage to reach prototypical speeds. :wink: I typically get between 2 - 4 hours out of one of those packs, which is more than ample for most operating days. Since the packs are usually removable, I can just swap them out to recharge them. In instances where the batteries are not removable, I try to fit higher-capacity packs in the locos if I can, but that’s not always possible.

My second thought: I’m not a huge fan of wiring Li-Ion packs in series or parallel to get more voltage or longer capacity. You can buy packs of varying voltages and capacities pre-wired with built-in charge/discharge protection for the entire pack, so why not just buy the pack at the voltage and capacity you need. The manufacturer has done the dirty work for you in those cases. While I’m not nearly as “nervous” about Li-Ion packs as some are, I’m also of the belief that the manufacturers know a lot more about the intricacies of how things work to where I’m just as happy to trust their judgment and just have one pack to charge and discharge at a time in a given installation.

Later,

K

In my locos – 4-6-0s (both old and Annie drives), Bachmann 2-8-0, K-27, Aristo FA-1s, Bachmann Shay – I’ve never needed more than 14.8 volts. 3 amp hour is likely fine for a 4-6-0 – my 5 amp hour battery lasts close to 10 hours with a light load.

My GP 9 does just fine with a 14.4 v battery. It will reach an estimated 45-50 smph with 20 tank cars having along behind. I doubt that you will need more voltage.

I use this pack in my smaller locos, like my Lionel Atlantic, and my Annie. It has been on sale for as low as $15.00 ea. so keep your eye on it, for when it returns. Many on this site have had good experiences with this product. I’ve gotten five hour runs with my Atlanic and four cars, a tender and a caboose on a level track at a show. The battery always lasts longer than I do.

Kevin Strong said:

My second thought: I’m not a huge fan of wiring Li-Ion packs in series or parallel to get more voltage or longer capacity.

The only reason I would do it this way is to make it fit in a non uniform space for example if I had to place them like /\ in order to make room for the cone on the speaker. Now after reading a little on Greg’s site about speakers he recommended the Vistaton line of speakers. Now being a audiophile in a former life I understand enough about speakers to be dangerous. With a few notable exceptions the deeper a cone and the bigger the magnet on a given size speaker the better the sound (other things also considered). But with that said this isn’t a car stereo, and other things need to be taken into account. Visaton makes a 2 1/2" round speaker that is water resistant and only 3/4 of an inch tall. Not very deep but internally magnetized, its height will more than give me enough room to run a 14.8v 2600mAh pack flat. Built with a baffled enclosure the speaker should produce a bit more bass. I have one other option I am looking at and that is to use a oval or rectangle shaped speaker that has a taller magnet and see if I can put a cubed shaped pack in in front or behind the magnet or an end to end arraignment (2X2) along the sides. Would require a wonky shaped enclosure but would allow for a taller magnet. I never in my life would have dreamed I would be using my audio skills in my trains. I have shoe horned speakers in weird/tight spots before with wonky enclosures. Sealed air space is sealed air space volume counts not shape.

So in all I think that is the solution. I am relieved to hear that no one believes it needs more than 14.8v. If the 2600 mAh battery doesn’t provide the run time I like I can always spring later for a higher capacity pack later.

Steve Featherkile said:

My GP 9 does just fine with a 14.4 v battery. It will reach an estimated 45-50 smph with 20 tank cars having along behind. I doubt that you will need more voltage.

I use this pack in my smaller locos, like my Lionel Atlantic, and my Annie. It has been on sale for as low as $15.00 ea. so keep your eye on it, for when it returns. Many on this site have had good experiences with this product. I’ve gotten five hour runs with my Atlanic and four cars, a tender and a caboose on a level track at a show. The battery always lasts longer than I do.

That is the one I was considering when thinking 2200 mAh. There is a 2600mah version with the same dimension but of course pricier (double or more). Any option besides the one you list jumps in price considerably. I was not really even thinking of making the batteries removable but given the price and the size that is a very easy option by wiring in a plug. So have a spare pack may be a better plan considering I likely will not run the 2200 mAh into the ground very often.

When I had nicads, I split the pack into 2 bundles of 7 and filled the boiler.

I tend to run sporadically and that chemistry needed me to plan ahead. Li-ions have a great shelf life so I made the switch, but… unlike Boeing, I don’t have fire insurance on my locos and can’t afford on board fires… so this time around, I’m trying to follow Kevin’s lead and make them removable to charge. I do have a burnout oven I can charge them in! The fire hazard is reduced, but still a possibility.

Until we get black smoke, I won’t waste the volts on it.

I have mixed emotions about sound… mostly I like it, but sometimes it intrudes. Get one with a volume control.

John

Now I have heard the scare with LiPo burning up but not Li-Ion. I thought that was the main reason everyone uses Li Ion instead of LiPo. If I am going to take them out to charge and charge them in a burn out oven (they actually sell bags for such a thing) then why wouldn’t I use LiPo batteries? Far more available in different sizes and configurations. I can walk into any RC Car shop and buy LiPo till my hearts content. They all take there batteries out and charge them in bags. The whole reason I was steered away from LiPo in my original inquires was because of the fire hazard and not much worry with that in Li Ion.

Now I have to ask, has anyone actually had a Li Ion or LiPO battery that had sufficient overcharge protection with PCB wired in and a smart charger programmed correctly catch fire? The R/C car guy at my local store has heard stories but never had it happen or knew anyone that had it happen.

Hmmm my understanding was we didn’t need the rapid discharge that LiPos allow and that we would get better run times with li-ion.

I thought the LiPos are safer, but what do I know?

I’m glad I brought it up.

John

Devon Sinsley said:

David,

Track power was never really a consideration. I have zero intention of having track power, most all of my club is RC and to have built it with power pickups would have to have been deliberate in construction since the driver spacing and chassis is all together different than the 10 Wheeler.

Based on yours and others observation 14.8 will more than suffice.

Devon, you misunderstood my post. I said that if you had run the thing on track power, then you would have an idea of how much voltage you need. I know track power isn’t even on your horizon for your layout. My point was, if you had run it on track power, and you knew it was a, say, 18 volt supply, and you liked it at a throttle setting of say just over halfway, then you could guestimate that about 10 volts would give you the performance you wanted. That’s what I was trying to say.

As a side note, I don’t take knife or saw to any locomotive until I have run it (on track power) to make sure it actually works first. I don’t want to put the time and effort into bashing the heck out of something, only to find out that its a stone. That’s just my viewpoint.

Devon Sinsley said:

Now I have heard the scare with LiPo burning up but not Li-Ion. I thought that was the main reason everyone uses Li Ion instead of LiPo. If I am going to take them out to charge and charge them in a burn out oven (they actually sell bags for such a thing) then why wouldn’t I use LiPo batteries? Far more available in different sizes and configurations. I can walk into any RC Car shop and buy LiPo till my hearts content. They all take there batteries out and charge them in bags. The whole reason I was steered away from LiPo in my original inquires was because of the fire hazard and not much worry with that in Li Ion.

Now I have to ask, has anyone actually had a Li Ion or LiPO battery that had sufficient overcharge protection with PCB wired in and a smart charger programmed correctly catch fire? The R/C car guy at my local store has heard stories but never had it happen or knew anyone that had it happen.

I googled ‘Li-ion battery warnings’ and got this from BatterySpace;

“Please realize that batteries might cause damages like leaking, fire or explode when misuse or defective.
It is your responsibility to double check and make sure your devices have necessary protection circuits.
When charging Battery Pack, please put battery in a fire proof container. Always charge in an isolated area, away from other flammable materials. Ex: wood bench, carpet unattended.
We are only responsible for the products we sell.We are NOT responsible for any damages and consequences damages by using our products.”

I dunno, but that makes me cautious.

John

David,

I got it now. Yeah it would have been wise to test it before cutting it. But to be honest this Thing sort of evolved. From the very start it was going to be more static with the hope of maybe running it. Then when I got serious about making it a runner I had already chopped. Nice thing about being a Bachmann 10 wheeler is even if the motor is bad it’s not a total loss easy to replace.

John that warning is ominous and probAbly should be heeded but in practice it doesn’t seem to happen very much considering no one seems to ever had it happen. With that said it is really is smart proabnaly to remove it and avoid any risk.

Devon,

I use Li-Po batteries in most of my converted loco’s and the same batteries in R/C planes, cars, trucks and drones. As you suggest they are plentiful and offered in different shapes, physical sizes, capacities and voltages at very reasonable prices. Can they be problematic, yes same as Li-Ion as either offering is comprised of like chemical matrixes. Either technology reacts to abuse with the same potential as the latter.

Li-Po batteries are widely used in everything imaginable, cell phones, laptops, personnel electronic devices (Bluetooth headsets and more). Li-Po or more correctly Li-Ion Polymer cells market share in the Lithium world is second to none…

I list below minimally the variables of typical Li-Ion and Li-Po cells with regard specifically to integral safety features:

Li-Ion cell:

1). Standardized metal tube surrounds which offer some protection from physical damage.

2). Integral mechanical pressure relief vent.

3). Integral positive thermal coefficient switch (PTC). Reacts to heat rise becoming resistive. Or acurrent interrupting device (CID) either device provides short circuit protection.

4). Not capable of high discharge currents.

Lithium-Ion Polymer cells (Li-Po):

1). Flexible foil-type polymer laminate pouch form factor (provides expansion relief with heat gain).

2). Capable of High discharge currents.

PCM/PCB protection circuit boards are ancillary devices typically utilized and installed via second party battery assemblers/resellers of assembled battery packs, these devices can be utilized with either Li-Ion and or Li-Po cells/batteries.

PCM/PCB protection circuits are widely integrated into Li-Ion batteries and are just as applicable to Li-Po batteries (yet seldom used due to high current needs/desires attainable with Li-Po’s). For our train purposes Li-Po’s and PCM/PCB’s work as well as they do for their Li-Ion battery counterparts.

With Li-Po’s I use SMART chargers with cell balance features. This provides the ultimate cell/battery protection undercharge/discharge/cycling. The balance feature monitors individual cell performance/values and adjusts the need and or reacts to the individual cell while connected to the charger. This protection and cell balancing technology is FAR superior to any PCB/PCM currently offered. I also have my Li-Ion batteries fitted with balance charge pigtails in lieu of onboard PCB/PCM’s. Caveats; no onboard voltage monitor, which can be provided by other ancillary devices. Protection for short circuit and excessive current draw provided by the appropriate simple fuse.

The propensity for problematic behavior under charge is well known and mostly realized in the early exposure to end users. Human error was/is markedly the well documented reason for these failures. Improper chargers, improper charge values, improper charge regimens, excessive time under charge, errors in cell/battery values and requirements and such leads to failure modes.

FWIW: Not all Li-Ion battery packs have integrated PCB/PCM’s. As I allude to above these are ancillary devices added by the battery packagers/resellers or not! This secondary safety feature obviously help mitigate the aforementioned human error factor.

We’ve all heard or read about the horror stories, I’ve never had a failure and worked through hundreds of batteries over the years. I’m not aware of any friends or associates experiencing failures either. It’s my belief that we hear of the problems thousands times over as compared to the happy camper. In other words of the 12 billion or so Lithium cells sold since 1995, how many failures truly exist?

Michael