Can USB rechargeable batteries be wired in series?

[XiliX]

I've seen a few members discussing running fans from rechargeable USB batteries.  Most fans are 12v and most USB rechargeable batteries are 5v.  I was wondering if two USB cables could be spliced so that the ground from battery 1 is soldered to the positive from battery 2, and then the positive from battery 1 is connected to the red lead going to the fans, and the ground from battery 2 is connected to the black lead going to the fans?

 

If so, this should provide 10v for the fans.  However, I'm not sure if this would affect the overall recharge life of the batteries or damage them in any way.  I am just trying to find a uniform rechargeable power source for my helmet fans. Has anyone tried this or have any comments or suggestions as to its viability?

 

Thanks for any and all replies.

 

[LordNikon]

There could be battery damage issues if the batteries are not completely even. Depending on the battery chemistry.

But why not use a 5V fan? They are less common, but do exist.

A USB fan perhaps? :-)

[XiliX]

Thanks for the tip. I haven't seen 5v fans, but I'll begin looking. If I use the USB batteries in series, I would get two identical units.

[Sly11[Admin]]

This is one of the extremely rare times you will ever hear me recommend evilbay, but I got 5 x 5volt 50mm fans from there. They came from China including postage for $6.00.

My thinking was, run 2 fans and have spares incase of failure. Haven't lost one yet, used them over the last 9 months, so best $6 I have spent.

 

Just to add, you can get Two wire or Three wire, go the Two wire, red and black you can't go wrong.

I also run lithium rechargeable batteries in series, standard Energiser x4 AA, bought them from local supermarket in a pack with the fast recharger, they charge from dead flat to full in about 15 minutes.

 

 

Sent from my iPad using Tapatalk

Edited February 26, 2015 by Sly11

[wonko]

Are the batteries Li-Po or Li-Ion.  The most important thing to look for are balanced cells (Especially Li-Po), not necessarily getting "identical units"  Li-Po batteries can be extremely dangerous if not charged and handled properly.  Li-Ion are a bit more forgiving, but can still cause damage if over or under charged.  Also, as far as I know you would need to charge each pack separately.  You would be better either buying a pack that already has the volts you want, or purchasing 5 volt fans.  I'm not sure if you're aware, but 12 volt fans can be run off 5-6 volts without problems.  I run 2 12 volt fans off of 4 AA batteries (6 volts) and have no problems at all.  The fans will run slower, but they will still move a fair amount of air and are much quieter than running 12 volt fans at 12 volts.

 

Brian