For anyone doubting Tony, the PolySwitch manufacturer states they can be used in parallel.
Greg
p.s. to keep perspective this discussion started when it was stated you could simply parallel 2 packs and charge with a single charger. I still maintain that taking two packs that would charge at 3 amps each for a fast charge… it’s not a good idea to simply parallel them and use a 6 amp charger…
Tony Walsham said:
Wiring two separate packs in parallel is not only do-able, it is easy peasy.
As I see it there are two reasons why you would want to wire two packs after the fact in parallel.
- To enable higher current consumption.
- To extend run times.
Two separate packs (each with a suitable pcb) wired in parallel, should each be diode protected on the output. That prevents one pack backfeeding into the other.
The packs need to be the same chemistry, same voltage and same capacity.The diodes need to be able to handle the current. Like this;
Each pack is charged separately via the DC coax jacks on either side.
I use 3 amp Polyswitch fuses. If one Polyswitch trips, the other will follow suit as it cannot handle 6 amps on its own.
Tony, I’m confused by the presence of the grey wire. My batteries only have a red and black wire.
Getting off track for one second here, so please indulge me, my batteries are NiMH and I have some 12V (10x1.2V) packs that I have made from individual cells, would connecting a second in parallel be the same as if I made a pack with 20x1.2V so therefore I could charge them in parallel?
Not trying to be a smart Alex here this is a genuine question, because if I can it would make my life a little easier as I could bulk recharge my batteries.
By the way I also use LiPO but would never connect the in parallel they are scary enough singly I just buy bigger capacity ones. They are not fitted with protection boards , I rely on my charger not to overcharge them and my motor controllers are programmable so I set the discharge voltage higher than the recommended voltage (reduces runtime a small bit but its safer).
Steve Featherkile said:
Tony Walsham said:
Wiring two separate packs in parallel is not only do-able, it is easy peasy.
As I see it there are two reasons why you would want to wire two packs after the fact in parallel.
- To enable higher current consumption.
- To extend run times.
Two separate packs (each with a suitable pcb) wired in parallel, should each be diode protected on the output. That prevents one pack backfeeding into the other.
The packs need to be the same chemistry, same voltage and same capacity.The diodes need to be able to handle the current. Like this;
Each pack is charged separately via the DC coax jacks on either side.
I use 3 amp Polyswitch fuses. If one Polyswitch trips, the other will follow suit as it cannot handle 6 amps on its own.
Tony, I’m confused by the presence of the grey wire. My batteries only have a red and black wire.
Steve not trying to be Tony but not sure how often he checks in. But I do know what your looking at because I have used some of Tony’s charges. What you are looking at is just the charging schematic on the lt. and rt. with the red,black and gray wires are the DC coax jacks wear the charger plugs in. At the bottom is wear the batt. + and - go. one batt. on both sides out put to your engine goes.in the center. hope this helps
Richard
Yes Richard, the battery packs only have two wires. Red & Black. They are each connected one to either pair of Battery IN terminals.
The two DC coax jacks on either side are are actually each an SPDT switch. The grey wire makes up part of the negative circuit when not charging.
Be advised using regular silicone diodes will drop the output voltage .7 of a volt. I used more expensive Schottky diodes which drop just .2 of a volt.
As the charger is plugged into either jack, the internal switch isolates the battery pack from the running circuit for charging. Remove the charger plug and the running circuit is resumed on each side.
They are not ON-OFF switches. Such an ON-OFF switch would still be required on the Battery OUT terminals.
I built a few of these adaptor “plates” some years ago for placement in a fuel tank of large diesels so that one jack was on each side of the fuel tank. 12 years ago they were for PB, NiCd & NiMh chemistry. No allowance was made for balancing pigtails found on some batteries nowadays such as Li-Po.
The Li-Ion batteriy packs I sell are made by the Australian Sanyo agents and are fitted with battery protection circuits which internally balance the packs as well cover overload and overcharge.
I use 18500 size and 18650 size cells in various shapes to suit particular situations.
My packs are expensive & they cannot be exported.
I am by no means a battery expert. I willing will bow to Greg and Michael G when it comes to battery expertise.
Steve Featherkile said:
Tony, I’m confused by the presence of the grey wire. My batteries only have a red and black wire.
Steve
After rereading this thread 3 times I have determined that is the reason why the “Battery Won’t Fit”
If you would have kitbashed it into an F45 like suggested earlier in the thread then the grey wire would surely have fit!
It would help if the diagram of the sockets actually showed the switch mechanism, not just 3 unconnected contacts.
Tony is using barrel connectors.
Looks like the center pin goes to the red wire, with or without the plug in the socket.
Plug out of socket, the “switch” you don’t see connects the black to grey and completes the power output.
Plug in the socket, the switch is open, no output power, and the negative side of the barrel plug (outer shell) connects to black to charge battery.
Downside is you have to rely on the internal switch working and being reliable, upside is it is really hard to do anything wrong, charging automatically disconnects that battery from the circuit.
Pretty foolproof…
Greg
No disagreement from me Greg.
Very foolproof.
DC Coax sockets come in a variety of pin sizes. I standardised 2.5 mm centre pin size with a 5 mm barrel.
The reason I use them and not regular stereo type jack is because the former break before make, whereas stereo jacks short out as they are inserted.
If I had given a proper circuit diagram, someone would have asked for the pics of the actual physical connections.
I chose to show it this way so the average Joe could easily see how to wire them up themselves.
I have used literally thousands of those DC Coax sockets in my installation kits and never, repeat never, had a failure. They can switch 5 amps reliably. As shown above, each is only required to carry 3 amps for a total of 6 amps.
The only real problem is the metal cases of the sockets have (in this case) a ground potential, which means they should not really be used on metal bodied locos. Perfect for plastic bodies.
Have you found a good supplier for us in the US?
Greg
Sorry, can’t help you with a source in the USA.
I buy mine locally from Altronics.
luv you tony, in the US, diodes are silicon, silicone is what you see filling out bikinis (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)
Greg
Greg Elmassian said:
luv you tony, in the US, diodes are silicon, silicone is what you see filling out bikinis (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)
Greg
…Which is why I described them as regular silicone diodes. Schottky diodes are not the same.
No harm in trying to find something wrong with what I wrote. EG a spelling mistake. Thanks for the lesson.
Every Battery install I have done I use Tony’s BIK-U6 real clean and easy to use and have some over 10 years now. If you do your own installs you should look at these.
Richard
was just having some fun tony…
Greg
Me too!!
You are so predictable Gerg, it is a bit comical.
(@)(@) I always though that the purpose of silicone was to make caulks stiffen up.
Todd Brody said:
(@)(@) I always though that the purpose of silicone was to make caulks stiffen up.
Ah Ha Ha Ha Ha! Good 'un. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-smile.gif)
