I dropped my Shay off to Jonathan Biese yesterday (Electric-Steam Model Works) to have my Nicad replaced with a lithium but forgot to ask him a question. I have a bettery car that I use behind the Shay. It is a Nicad. Can I mix the two?
Doug,
Kinda depends… What do you mean by mixing the two? If you’re asking can you source power simultaneously from both, I’d suggest NOT! But there are variables that could be in play that would allow such use. That said it’s unlikely your equipment is rigged accordingly. However if your equipment power sources are electrically isolated from one another it’s plausible to run them simultaneously providing there voltage ratings are closely matched, i.e., 14.4v NiCD and 14.8v Li-Ion or what have you.
If it were me I wouldn’t go there… Unless the batteries were like technologies and even then I’d want them electrically isolated from one another.
A Lithium battery charger is an absolute must for you batteries.
Michael
Mixing battery technologies is never a good idea.
That said…You could install a switch that would allow you to change from one battery pack to the other but the two must always be kept separate! Then again, charging could be a nightmare if you have the battery car connected to the loco!
What will happen, one battery will have a higher voltage and amperage, it will try to power the “weaker” battery. Batteries are not designed to function this way…Best case, you kill your pack, worst cast, fire.
I’d just avoid the trouble and not do it…
Michael is correct.
Jon usually installs a charge jack that can double as a port for extra batteries in a trail car. The DC co-ax charge jack is in fact a small SPDT switch. As the trail car plug is inserted it mechanically isolates the negative (-) of the on board batteries. In which case it does not matter what type of chemistry the batteries are. Neither does it matter what the battery pack voltages are, other than if they are mismatched, there will be a difference in the max speed.
Tony Walsham said:
Michael is correct.
Jon usually installs a charge jack that can double as a port for extra batteries in a trail car. The DC co-ax charge jack is in fact a small SPDT switch. As the trail car plug is inserted it mechanically isolates the negative (-) of the on board batteries. In which case it does not matter what type of chemistry the batteries are. Neither does it matter what the battery pack voltages are, other than if they are mismatched, there will be a difference in the max speed.
Now that is a sweet feature.
Mark.
Here is the circuit if you want to do it yourself.
(http://www.rcs-rc.com/pics/Drawings/BIK-U3-Battery-Wiring.jpg)
I use the aforementioned DC co-ax charge jacks as on-off switches in a few smaller loco’s. In these circumstances I use a dummy plug inserted in the charge jack for the power OFF position and a second plug wired with a pigtail connected to my charger is again inserted in the charge jack for charging. This works well for me with locos/tenders with limited space. And so I don’t forget to turn off the loco the sound emitting from the onboard card makes it known…
My loco’s are equipped with Airwire and/or QSI equipment as well as Lithium power. I also utilize Lithium batteries and chargers with cell balance technology. This affords me the ability to monitor individual cell performance/condition while charging and running or not!
Michael
Jon did the original installation so ut does have the jack. I’m “electrically challenged” so I wasn’t sure how it all works. I knew I could just plug the lithium charger in that way but that was all. I’ll double check with Jon but I think I’m a happy camper!
Doug.
One word of caution.
Do NOT plug the trail car batteries in with the ON - OFF switch OFF. Only plug the trail car batteries in when the switch is ON.
Another word of caution.
Similarly, do NOT plug the charger in when the switch is ON. The charger may have a high voltage in which case it might exceed the voltage limits of the ESC and a sound system.
Thanjs Tony. My natural inclination would have been to do it the WRONG WAY!.
Tony Walsham said:
Mark.
Here is the circuit if you want to do it yourself.
Thanks Tony, we’ll give 'er a go!
Mark V said:
Tony Walsham said:
Mark.
Here is the circuit if you want to do it yourself.Thanks Tony, we’ll give 'er a go!
Don’t forget the wire that goes diagonally across the back of the switch, or the circuit will not work.
Ah, sneaky little devil!!! Honestly I might have missed that.