Large Scale Central

What's wrong with this ?

Electronics Power and Sound
#21

John Caughey said:

The batteries are dense and a sharp bounce could depress a weak spring allowing a battery to break contact. Horizontally there is no such condition.

What did I win?

Bragging Rights! Or the old battery holder if you want it. Here it is.

There’s a considerable difference in the springs between the old one and the new one in my earlier photo above. I had already added small brass screws to assist with the battery contact, as you can see. The solution came to me when I realized I was jiggling the batteries every time. And yes, LiIon 18650s are quite heavy.

#22

"Bragging Rights! "

Works every time!

Uh I’ll pass on the prize.

#23

A nicad that size is way heavier. Lithiums, like the element are lighter than any other battery for the same volume.

I see you were homing in on the problem, as your modifications show. Also the older holder does not seem to wrap around the batteries as much.

Greg

#24

Well, let me comment that I have had some feedback about the undesirability of using those cells and charging them in that kind of holder. Hopefully the critics will add their 2 cents so we can all understand the issues.

Note that I am NOT charging the batteries ‘in situ’ in the holder shown. While the loco has a charger socket, my batteries came with an external smart charger so when I charge them, they are removed from the loco.

In addition, there is no protection for discharge, or short circuits. I will probably add a pcm to provide some protection in future. As I only run on a friends layout for maybe 1/2 hr, I do not think I will ever discharge them enough to damage them.

#25

A fuse would be a good start, cheap and easy.

Charging in that holder? My concern would be related to my charging current, as long as you are not super fast charging it should be fine, and LESS than the current flowing when running the loco!!! Think in that context.

Greg

#26

Greg Elmassian said:

A fuse would be a good start, cheap and easy.

It does have a fuse underneath - an actual fuse which blows occasionally. I have a 5A fuse from xmas tree lights in there today. I plan to fetch some Polyfuses from MD and install them instead.

Charging in that holder? My concern would be related to my charging current, as long as you are not super fast charging it should be fine, and LESS than the current flowing when running the loco!!! Think in that context.

Greg

Good point Greg. The boxcab came with 8 AA cells, and I switched to LiIon rechargeables, but I don’t have a plug-in charger here (I have one in MD for the 2x11.1V packs in my EBT #15.) I figure for the moment it is far safer to charge them out of the loco and out of the house!

#27

I agree Pete.

Based on what I saw, a little spray on anti-corrosion “grease” would be great on those battery springs. What I often use are products for boats. Lanocoat spray is great, keeps corrosion/oxidation/rust away, and it is basically spray lanoline, safe for everything (even good for your skin)… there are others, but you want something to coat the springs which are normally thinly plated steel, thus the rust you see.

Regards, Greg

#28

It also looks like you have two different cell manufacturers and two different milliamps levels, 1 Panasonic and 3 Sony / LG. Your pack will only be as good as the weakest cell, so if the Panasonic cell is 3400mah and the Sony’s / LG are 2800mah, your pack will never reach it’s full potential of 3400mah.

#29

Rick Isard said:

It also looks like you have two different cell manufacturers and two different milliamps levels, 1 Panasonic and 3 Sony / LG. Your pack will only be as good as the weakest cell, so if the Panasonic cell is 3400mah and the Sony’s / LG are 2800mah, your pack will never reach it’s full potential of 3400mah.

Don’t know where you got that idea. I bought them all at the same time.

#30

And the new horizontal battery layout did indeed solve the problem. No glitches, no jiggles.

#31

A question about the battery holder, is it made for the Li-ion cells or is it a standard AA holder?

My understanding is that the 18650 Li-ion cells are longer than AAs so you may be deforming the holder and over compressing the springs by removing the cells individually to charge them resulting in mechanical failure of the holder over time.

I would search for tagged cells and make a pack up then charge that, I did this with a AA NiMH packs I made, I used the holder body to mount them and took all the wiring out I learned that the less mechanical connections the better the reliability from my experience in aircraft/helicopter wiring (helicopters vibrate like hell).

I charge all my batteries at 1/10 the capacity so 5000mAH battery gets charged at 500mAH, this takes longer but I sacrifice time for safety and with a low charge current I have had no issues to date (over last 8 years).

Just food for thought.

#32

Those are 4/3 A, a standard size, different from an AA. No way a 4/3 AA fits in a AA holder. Therefore it clearly must have been made for that battery length.

#33

Also said 3.7v for each cell…

#34

Greg Elmassian said:

Those are 4/3 A, a standard size, different from an AA. No way a 4/3 AA fits in a AA holder. Therefore it clearly must have been made for that battery length.

Thank You for clearing up the size difference for me

#35

John Caughey said:

The batteries are dense

Just so it’s those and not the railroader.

(https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#36

Pete Thornton said:

That’s a neat little boxcab. Siderod drive makes it look like it is rushing frantically to get somewhere.

#37

Forrest Scott Wood said:

Pete Thornton said:

That’s a neat little boxcab. Siderod drive makes it look like it is rushing frantically to get somewhere.

That looks remarkably like my 7/8 boxcab

#38

Forrest Scott Wood said:

John Caughey said:

The batteries are dense

Just so it’s those and not the railroader.

(https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

Hasn’t bothered me a bit!(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#39

Bob McCown said:

Forrest Scott Wood said:

Pete Thornton said:

That’s a neat little boxcab. Siderod drive makes it look like it is rushing frantically to get somewhere.

That looks remarkably like my 7/8 boxcab

I really like your boxcab Bob. She looks like she actually works for a living.

#40

David Maynard said:

I really like your boxcab Bob. She looks like she actually works for a living.

Boxcab Bob, a name which sounds like good start for a railroad cartoon character.