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Are you wary of Li-Po batteries?
 Moderated by: W C Greene Page:  First Page Previous Page  1  2  3  4  5   
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 Posted: Tue Sep 8th, 2015 12:12 am
   
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Tramcar Trev
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Herb Kephart wrote:
Thanks Bob, and bookmarked.

Last time that I tried to turn a three cell LiPo into a two cell, I managed to stab the bloody thing with an xacto knife and it had a hissy fit. If I do in again, I'll know better.

(axe?) 

Herb

Did I tell you Herb the best tool for separating cells is a plastic egg lifter or a plastic, non metallised, picnic knife???



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 Posted: Tue Sep 8th, 2015 09:27 pm
   
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Pete Steinmetz
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Rod Hutchinson wrote:
Pete,

I have picked up on your comment and similar from other sources.

Could it be that there are possibility 3 levels of LiPo quality in descending order?

1. Hi end cameras, computers etc.
2. Bricks and mortar RC shops
3. If so, what would you view be on 3rd party providers such as those on eBay?


I supposed there could be many levels of quality. I put RC batteries in the low quality. E bay is buy at your own risk. It is hard to tell from the limited descriptions and specifications.



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 Posted: Sat Mar 12th, 2016 10:56 pm
   
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Bob D
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Has anyone in the model railroading world actually witnessed a train catching fire from using LiPos that were charged according to specs? My LiPo charger says to charge them at 1amp/hr. It takes 2 hours to charge a 2000Mah pack and 2hrs-15mins to charge a 2200Mah pack.

The only fires I've read about were from packs installed in planes or cars that get jostled around quite a bit or from fast charging.

I keep seeing the same folks on other forums express caution about using LiPos, but have yet to seen a train go up in smoke/flame, and of course they have provided no proof of it happening.

BobD.

Last edited on Sat Mar 12th, 2016 11:00 pm by Bob D



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 Posted: Sun Mar 13th, 2016 03:42 am
   
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Pete Steinmetz
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Bob D wrote:
Has anyone in the model railroading world actually witnessed a train catching fire from using LiPos that were charged according to specs? My LiPo charger says to charge them at 1amp/hr. It takes 2 hours to charge a 2000Mah pack and 2hrs-15mins to charge a 2200Mah pack.

The only fires I've read about were from packs installed in planes or cars that get jostled around quite a bit or from fast charging.

I keep seeing the same folks on other forums express caution about using LiPos, but have yet to seen a train go up in smoke/flame, and of course they have provided no proof of it happening.

BobD.


Bob:

You must have a lot of space to be able to use a 2000 ma pack. At a 1 amp charge rate, you are charging at 1/2C which is kind to the pack.

I have never heard of a train catching fire.

The best way to be safe is to use a pack with a protection circuit. The RC guys are not able to use protection due to the high discharge rates.
Train guys have much lower discharge rates and are encouraged to use packs with protection.

I use 240ma, 400ma, and 450ma packs. All have protection. Protection circuits, called PCMs, protect against over charge, over discharge, and short circuits.

None of the cells I use are from the RC world. All are low discharge rate cells.

Never had a problem

Pete Steinmetz



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 Posted: Sun Mar 13th, 2016 12:30 pm
   
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Bob D
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Pete,

I'm in O scale, so I do have a bit more space than those in smaller scales.  A 2000Mah, 9.6v, NiMh pack is 1-1/8"x1-1/8"x4", a 2200Mah, 11.1v, LiPo pack is 3/4"x1-3/8"x4-1/4".

I think if a person follows some basic guidelines things will be fine:

Never quick charge
Never poke holes
Never cut both wires at the same time (I actually saw someone try to measure the distance between terminals on a 12v car battery once with his metal tape measure, should have seen the look on his face when the tape went inside the housing while the end hit the floor)
Secure the battery so it doesn't move

The LiPo packs I'm using don't have a PCM installed:

LIPO PACK

I just checked the one in my Williams brass 4-8-4 and I see no bulging or any deformation and I do balance charge them.  I wonder why they would even sell a LiPo pack w/o the PCM/PCB if it was so critical?  Obviously they're being used (this one says for helicopters) in conditions that are more unforgiving than our trains.

BobD.



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 Posted: Sun Mar 13th, 2016 01:45 pm
   
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Pete Steinmetz
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Bob:

The PCM on a LiPo pack typically trips at 3A or 5A discharge. The RC motors can draw more than that.

Flyers wouldn't want to hit the throttle and have the PCM trip. Then the RC becomes a brick.

Pete



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 Posted: Sun Mar 13th, 2016 02:12 pm
   
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Bob D
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I flew RC back in the 70s using fuel with castor oil mixed in. Had a couple of bricks fly into the ground back then too :bang:

My steam engines typically draw around .75amps, haven't converted a 2-motor diesel yet.

All the naysayers on the other forums are trying to equate our trains to RC planes and such, to me it's not quite the same thing.

Bob



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 Posted: Sun Mar 13th, 2016 03:01 pm
   
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W C Greene
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Naysayers have spent their money on DCC stuff and don't want to hear or know about something that is (my view) superior.

There...take yer shots.
Woodie



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 Posted: Sun Mar 13th, 2016 03:53 pm
   
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Bob D
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I agree Woodie!

I don't know about the other BPRC systems, but Tony Walsham's RCS stuff was very simple to install and operate.

I don't have smoke (don't want it) or sound (I would like to have steam chuff though, timed to the rotation of the wheels), but I do have excellent motor control, headlight, backup light.

When I want to run, it's a simple process of turning on the Tx then the Rx, then direction and speed of my choosing. No books to read, no track to clean, no layout wires to run/solder.

There was one magazine that ran numerous monthly articles on using DCC, seemed like it took them 2-3 years to do the whole thing. Some of us don't have that long :old dude:

The only thing I regret is not putting BPRC in my engines 1st. I "wasted" a load of $$$ installing the MTH DCS PS2 electronics only to replace them with BPRC, I have 8 sets of circuit boards I need to sell.

Bob



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 Posted: Sun Apr 16th, 2017 03:28 am
   
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Nice Guy Eddie
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Nothing more can be added to this thread


:f:


Eddie



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