Model Boat Mayhem

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: MadMax on September 27, 2015, 10:49:15 am

Title: nicads
Post by: MadMax on September 27, 2015, 10:49:15 am
hi
   can any body tell/show me how to wire 2 12volt nicad /nims stick packs together to still get 12 volt
                                          hope sombody out there can help
Title: Re: nicads
Post by: grasshopper on September 27, 2015, 12:01:27 pm
If you have two similar voltage packs then connecting the two positves ( red) and two negatives ( black) together and then to the load ( Esc / controller)  should give you the same voltage but the combined amperage rating.


It is suggested that isn't advisable to do it though, you can get a situation where one pack is trying to charge the other if you have a weak cell that the resistance is low on.


Are you trying to get increased runtime?
Title: Re: nicads
Post by: petermun on September 27, 2015, 02:36:16 pm
You may find that Component Shop still stock a small Action circuit board that allows 2 batteries to be safely connected in parallel.   Inertia can probably confirm or otherwise.   Pete
Title: Re: nicads
Post by: Bob K on September 27, 2015, 03:34:06 pm
I recently bought one for two large 7.2V packs.  P103.  They are very good.  You do have to charge both batteries separately though. Lead acid batteries are not as sensitive, but ensure both are of the same style and age.
Title: Re: nicads
Post by: malcolmfrary on September 27, 2015, 03:38:47 pm
If you have two similar voltage packs then connecting the two positves ( red) and two negatives ( black) together and then to the load ( Esc / controller)  should give you the same voltage but the combined amperage rating.


It is suggested that isn't advisable to do it though, you can get a situation where one pack is trying to charge the other if you have a weak cell that the resistance is low on.


Are you trying to get increased runtime?
Similar isn't quite good enough - they both need to be the same and at the same state of charge.   If there is a dud high resistance cell in one of them, it will just mean, most of the time, that that battery will be ballast.  If both batteries are good, but one less charged than the other, they will try to even out.  They will do this rapidly, with quite a bit of energy dissipation on the way.
The action unit has diodes to stop this, but this in turn means that the better of the cells will carry all of the load until it gets down to the level of its companion, which will then join in.
Title: Re: nicads
Post by: MadMax on September 27, 2015, 06:11:01 pm
thank s to all that replyed to my post on the nicads......i understand a little more now and have ordered the
103 from action .......so thank you all
                                                                        regards
                                                      madmax