Garden Railway Forum

Hello all,

A few weeks ago I went to use my RH Little John and found that it was out of charge - I'd left it switched on, and it seems the battery drained. It won't accept a charge, so - following advice I think I've received previously - I think a trickle charger may be the way to go?

I own such a device, but don't really know how to use it - can anyone advise please? It has 6 settings, covering 50 mA to 300 mA - if I'm honest, I don't really know what that means, let alone which I should use and for how long...

Thanks in advance,

Andrew.

What batteries are they?

The battery will have a voltage and a capacity. The capacity will be in mAh (milliAmp Hours).

The setting on your charger will be mA. Therefore, if your battery is 1000mAh and you use the 100mA setting on the charger, then it will take about 10 hours to charge. Make sure that the voltage output of the charger is correct for the battery (if it is a 4 cell battery then it will likely be 4.8v).

For trickle charging, just put the charger on its lowest setting (50mAh) and leave it overnight.

WARNING: This assumes that the batteries are Ni-Cd or NiMh (i.e. 'normal' rechargeable batteries). If they are lithium of some sort (e.g. Lipo or LiFe) then let me know, as they need special chargers and procedures.

If the batteries were completely drained, and left like that for some time, they may not all charge again, and you should replace any faulty batteries, otherwise this will continually drain the good batteries.

Jimmyb wrote: ↑Sun Apr 10, 2022 9:15 am If the batteries were completely drained, and left like that for some time, they may not all charge again, and you should replace any faulty batteries, otherwise this will continually drain the good batteries.

Beat me to it, I was think they are likely to be FUBAR by now.

Oh dear...

Thanks for the advice all, much appreciated.

I'm afraid I have left it awhile though, probably a month or two, didn't know they'd be trashed so quickly - that's an expensive mistake!

Oh well, I'm attempting to charge them anyway, you never know...

Andrew.

Been there, done that.......

I've found this website is a good source of info on the care and feeding of rechargeable cells.

https://batteryuniversity.com/articles

It may well answer questions you didn't even know you had.


As I get older I'm developing the attention span of a goldfish and a memory like a sieve, so I've fit working headlights to my r/c battery models to remind me to turn things off at the end of a run.

If the prototype didn't have a headlight, I'd fit a small LED somewhere visible in the cab, like the control panel on a diesel, or the fire door on a steam loco.

The various little railmotors I've built don't have speed control, just an on/off switch, so it's pretty obvious even to me if they haven't been turned off......


Regards,
Graeme

It might be that only one cell in the pack has been damaged. Might be worthwhile disassembling the pack and testing each cell before trashing the whole pack.

Rik

[What batteries are they?}
{The battery will have a voltage and a capacity. The capacity will be in mAh (milliAmp Hours).}


Little John has 8 cells (MKI) or 6 cells (MKII)
These are AA size and the packs are supplied by Strikalite.
Typical costs for a made-up pack are £3 per cell.