Battery/RC LGB Krok headscratcher

WKDOR

WKDOR

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After five years of trouble-free running I have a head-scratcher of a problem with our most reliable Battery/RC powered loco - a very elderly LGB Krok.

Power is from two sub-C battery packs (6-cell and 8-cell = 16.8v nominal, overcharge = 18v). Control is a Railboss ESC, RC is Deltang, Sound is Phoenix P8. All stable for last few years.

Until now. On power up the RC connection is OK and Phoenix startup sounds start OK. The battery voltage measures 18v but the power to the ESC measures only 14v. As soon as I start turning the throttle up, the sound dies and the motor trucks turn only slowly. Voltage supply at the ESC and Phoenix card measures about 5v, whereas the battery still measures 18v.

The only item between the battery and the ESC is a small battery conversion module which is a switched and fused set of screw terminals:

http://www.gscalegraphics.net/uploads/2/5/7/7/25776635/bcm2_manual_a.pdf

I have replaced the fuse at 5A but that made no difference.

The loco has been in a recent collision!

What am I seeing here please? All suggestions as to possible cause or further diagnostics will be very warmly welcomed.

mike

Moderators please move if this is better under Battery RC
 
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You say collision...was the loco under power? was is also with throttle open for any length of time with said collision? I'm just wondering if and damage may have occurred to the esc from an excessive motor draw with the loco unable to move but power applied. What kind of 'collision' occurred?
 
nicebutdim said:
You say collision...was the loco under power? was is also with throttle open for any length of time with said collision? I'm just wondering if and damage may have occurred to the esc from an excessive motor draw with the loco unable to move but power applied. What kind of 'collision' occurred?
Click to expand...

A visitor drove into a buffer and then another train, so your suggestion may well be possible.

I don't have and can't get a replacement ESC so how could I test this theory?

Many Thanks

mike
 
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Do you know if it is the 5amp or 10amp esc? The only thing you can do is rule out other options first. Do you have any other batteries? Try them first as easiest to change. If that makes no difference check each bogie's current draw to make sure there is no motor issues/damage (although I'm sure one would work fine while the other would 'drag'). If all that seems ok then I'm afraid the esc is at fault. If it has been subjected to a high stall current then it could be that the output transistors on the esc have been damaged. Unless you really know what you're doing with all the test equipment then a replacement will be the only route.
 
it could well be the batteries. they may show 18V but perhaps due to age or damage they cannot sustain that output under load.
 
Anything bent / dislodged in the collision(s)?
Is the board you refer to touching something?
Is the charging socket damaged?
Trapped / chaffed wires to the motor(s)?

If all looks good, then it could well be the ESC.
 
WKDOR said:
A visitor drove into a buffer and then another train, so your suggestion may well be possible.

I don't have and can't get a replacement ESC so how could I test this theory?

Many Thanks

mike
Click to expand...
Sorry can offer no better advice than to get better visitors. However another solution when fixed, if you can severely restrict the Top Speed on any Train that you let visitors loose on. I am talking sub scale 30KPH.
JonD
 
stockers said:
it could well be the batteries. they may show 18V but perhaps due to age or damage they cannot sustain that output under load.
Click to expand...

Many Thanks to All. Yes visitors, eh?

I was hoping it might just be the batteries although I can assure you all that a swap will not be easy!

So I'll start with trying to by-pass/disconnect the little board with charger circuit, Thank you Phil and Greg.

mike
 
Update:

By-passed the charger/switch board and found everything OK.

Looked like the board/charge circuit, but which bit? The charge wiring was pretty inaccessible so I left that in and tried a replacement GSC BCM board - and bingo it appears to work OK subject to testing tomorrow.

Rigged up a separate test circuit and found that my charger doesn't like the suspect board.

Still a mystery how this all happened but the collisions remains a Possible/Likely cause - don't you think?

Thank you again to Phil and Greg. And to Neil Robinson who kindly sent me a msg/PM.

mike
 
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