Two ordinary wet cell batteries can either be connected by series or by parallel.

What happens if I have a contraption that enables these connections to alternate between series and parallel cycles in such a way that, in one cycle (first cycle) it connects these two batteries in series. In the next cycle (second cycle) it connects these two batteries in parallel connection.

The contraption moves fast (30 - 100 times per second) between series connection and parallel connection so that it becomes almost series/parallel "at the same time".

Can these two batteries in the first cycle (series) be arranged to discharge the battery and in the second cycle (parallel) be arranged to charge these two batteries?

If so, can we have the possibility of a battery system that can charge and discharge "at the same time"?


closed as unclear what you're asking by The Photon, pjc50, Andy aka, winny, SamGibson Sep 1 '18 at 22:18

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  • \$\begingroup\$ First you say that at one time it's charging and at another time it's discharging. Then in the next sentence you ask if this is the same as charging and discharging at the same time. No, it's not. It's charging at some times and discharging at other times. \$\endgroup\$ – The Photon Sep 1 '18 at 4:01
  • \$\begingroup\$ I'm voting to close this question as off-topic because the answer to the question is already included in the question. \$\endgroup\$ – The Photon Sep 1 '18 at 4:01
  • \$\begingroup\$ That type of thing is done every day in probably a billion battery installations. It's just not done that way. \$\endgroup\$ – Harper Sep 1 '18 at 4:02
  • \$\begingroup\$ Switching 30 times per second is not a microsecond. A million times per second is. \$\endgroup\$ – Blair Fonville Sep 1 '18 at 5:28
  • \$\begingroup\$ I think if you do it really really fast, the battery stays fully charged as long as you don't draw too much current. \$\endgroup\$ – Henry Crun Sep 1 '18 at 5:37

There are components available to switch batteries between series and parallel.

However, there are no problems for which that is the best solution.

Matching voltages by dynamic series/parallel connection is far better done with a buck or boost SMPS converter. The effect of charging/discharging 'at the same time' is better done by powering the load directly, and making up the balance of the power flow to or from the battery, using voltage conversion as required.


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