I dont have an Electrical degree for nothing…
Rick parallel it will be pulling from both packs…
so if you had 5 amp draw and use 2 packs in parallel it would pull from both 2.5amps… not just one… when charging you charge both pack by them self.
you don’t have to weldthem together… just hook them in parallel for more current and series for more voltage. Basic electrical laws…Hook an amp meter to the and see for your self… Heck Give me 2 sets and I do it for you on video to prove a point and send them back to you. If its shows I wrong then I will admit it. How are your battery packs made by putting them in series for the voltage and then in parellel for the current draw. so realy no different in paralleling packs.
Daniel’s basically right. No welding needed, just a good electrical connection. Power will be drawn pretty equally from both packs, meaning you can supply twice as much power, when they are in parallel.
Actually, unless you put a big load (more draw than one battery can supply) on it, you will not be really able to measure that in any practical way except by noticing that, as you would expect, two batteries last twice as long as one battery for the same load.
But really, looking at the original post, the key issue is not the batteries themselves but the pcb protectors that manage the charge on the batteries. My suspicion is that it makes no difference, but as to this point, I know nothing at all. It’d be a poor design that would not allow either configuration.
Conventional wisdom would say yes, you should be able to wiring a battery-pack in parallel with another, but this is lithium with a PCB dictating it’s output. The PCB only know’s what the battery parameters area when the cells are either welded in series or parallel prior to wiring them into the PCB (ie: 4 cell lithium and each cell is 2amps = 14.8V @ 2000mah). If you bypass one PCB and wire the cells in parallel to the other pack before it enters that PCB, then yes; your battery is now 14.8V @ 4000mah.
If you wire both battery-packs with two separate PCB’s in series, one pack will slowly over time (estimate - 3 months) discharge faster than the other, thus making the individual cells go out of balance. To gain more life out of your battery-pack, I would leave the packs separate and toggle between the two packs during operation.
Rick Isard
Cordless Renovations, LLC
RCS America
put a diode in series with the output so one pack can not charge the other but have separte charging jacks… and it will work cause one PCB will not effect the other… Do some reaonable thinking here…so it goes
battery, switch for charger, diode
---------------------------------- together output...
battery ,switch for charger, diode
One pack has no effect on the other…Try it…Rick…
Daniel,
No, all my lithium-ion battery-packs are welded in series and then in parallel prior to the PCB, then depending on which pack it is; there either welded to the PCB or inline soldered to the tips.
I wish you the best, and when your battery-packs go out of balance don’t hesitate to give me a call.
Rick Isard
Cordless Renovations, LLC
RCS America
http://freightsheds.largescalecentral.com/users/daniel_peck/Battery.pdf
Take a look at the PDF…
If this does not work then explain to eveyone in detail why, not just because…
As for batteries I go to the manufactory for them, cheaper that way with same warranty.
Isn’t this what Paul Norton did on page one of this thread? Apparently he has had great success using a 4-pole DT switch. I am actually using the same 2100 mah battery packs and following his diagram. Looks like a winner to me!
Hi Daniel, Here is a simple circuit that automatically blends two packs with diode protection on each pack. At the same time it allows individual charging of each pack.
YES THAT WILL WORK
but for some reason Rick says no…
Daniel,
My Mum taught me that if I cannot say something nice about someone don’t say anything at all. So I won’t say anything. 
Mike & Paul, how long have you guys been running your packs in parallel? Have you noticed any drop in battery preformance?
I’m assuming the guys flying planes are using LiPos? Not LiIon batteries? My RC car LiPos don’t have the PCB protection in them (wish they did sometimes) do you notice any preformance issues?
Tony, do you sell that circuit? And is it a parallel or series circuit? After my rectifier fun I have lost most of my desire to do any circuit work…
Thanks (and sorry for whipping up a hornets nest)
Terry
From the LiPo side of things…No change in performance. They too have PC boards. I plug multiple matched amp rated packs into a parallel connector board but charge seperately. I also never leave them in the plane “hooked up”, not due to battery discharge concerns but basic safety. I have been doing this for years.
I will be wiring my battery car just as Paul Norton outlined earlier. Looks good to me.
TonyWalsham said:Your right....Me Too.......
Daniel, My Mum taught me that if I cannot say something nice about someone don't say anything at all. So I won't say anything. ;)
Terry
My main activity has been non-train, where I have been happily paralleling batteries for decades, with great results. As to the trains, well, that’s mostly applying the same theory, accent on theory. As I mentioned above, any impact that the pcb’s may have is beyond my ken, and I’d rely on actual experience as a strong guide.
Michael
Terry.
I did make a few of those pcb’s but they are long gone.
The circuit places the batteries in parallel for drain.
The two charge jacks (RS # 273-1583), one on each side, are actually SPDT switches. They are wired such that when the charger is plugged in they disconnect the battery pack from the circuit. Remove the charger and the battery pack is once again in the parallel circuit. The two diodes prevent feed back from one pack to the other.
Terry Burr said:
Mike & Paul, how long have you guys been running your packs in parallel? Have you noticed any drop in battery preformance? I’m assuming the guys flying planes are using LiPos? Not LiIon batteries? My RC car LiPos don’t have the PCB protection in them (wish they did sometimes) do you notice any preformance issues? Tony, do you sell that circuit? And is it a parallel or series circuit? After my rectifier fun I have lost most of my desire to do any circuit work… Thanks (and sorry for whipping up a hornets nest) Terry
I ran my Dash 9 and SD-70 with my Evans power car for a couple of years. The output terminals of the switch were wired as shown with diodes on the positive terminals and a jumper across the negative terminals.
(http://ovgrs.editme.com/files/EvansPC/Wired.jpg)
When I added to an on-board battery pack to my Dash 9, I sold the power car to a friend. He still uses it for his big diesels. He drives me to our club railway every Wednesday and Saturday, so I am sure it is still performing well or he would have mentioned it.
Yes and like Paul I use diodes, I just eliminated the swithch as I pull my batteries out after my run. I have been doing so for a couple of years. Trueth be know I got the idea from Paul’s club website.(great sorce of info).
Extensive battery article in December Garden Railroading.
Michael Moradzadeh said:William Canelos' article, "Battery Packs Demystified", points out one of the downfalls of Lithium battery packs. To protect the battery pack from full discharge, the protection PCB cuts off the voltage completely and the train just stops dead in its tracks, most likely on a hill or in a tunnel, making it difficult to get the train back to storage. This forces the operator to guess when the pack might be ready to quit, and therefore never get the full run-time from the battery pack.
Extensive battery article in December Garden Railroading.
This problem is resolved with the G-Scale Graphics RailBoss Plus controls, which feature built-in low battery warning systems for Lithium batteries. A user programmable setting warns you when you have only a few minutes remaining on the battery pack by slowing the train to get your attention. Then you run it home before the PCB cuts it off. This feature takes out all the guess work and the need for monitoring run-times.
There is also a “hard cut-off” for use with Lithium Polymer battery packs not having a protection PCB, or to act as a backup to the Lithium-Ion battery packs’ protection PCB. For more information go to www.GScaleGraphics.net.
Quote:Those of us who run live steam are very familiar with this concept. You lose pressure at one of two spots: (A) the most inaccesable spot on the railroad or (b) the farthest point from where you are standing. :)
...most likely on a hill or in a tunnel, making it difficult to get the train back to storage.
Later,
K