Would it be okay to charge four identical 12V batteries in series-parallel, using a 24V charger, as shown?

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I am trying to create a 24V battery bank, so naturally I need to connect two 12V batteries in series. I also need a larger capacity than these batteries can supply, so I intend to wire up two more 12V batteries in parallel for a total of four. I have a 24V charger for this battery bank, but will it be able to safely and effectively charge all four of the batteries wired in this configuration?

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    \$\begingroup\$ It appears that your diagram has the 24 volt charger completely shorted out. \$\endgroup\$ – Andy aka Jun 2 '20 at 13:41
  • \$\begingroup\$ Not only is the charger shorted, but you need to make sure the current flow is corre3ct through each battery. \$\endgroup\$ – Solar Mike Jun 2 '20 at 13:47
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    \$\begingroup\$ If you post a diagram like that, you should not do anything with components. Stick to ready made. \$\endgroup\$ – Neil_UK Jun 2 '20 at 13:48
  • \$\begingroup\$ The comments above are valid but the larger question remains if a combination of batteries in series and parallel can be effectively charged \$\endgroup\$ – Jack Conway Jun 2 '20 at 14:14
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    \$\begingroup\$ You can only really float charge parallel lead acid batteries. \$\endgroup\$ – Andy aka Jun 2 '20 at 14:20

Charging and discharging batteries in series can lead to voltage imbalance over time. You can read more about it here. To get the most lifetime from your batteries, you can charge them in series but then you should have a charge balancing circuit.

  • \$\begingroup\$ A 12 volt lead-acid battery consists of six, 2 volt cells connected in series, with no battery mangement/charge balancing circuits. Why wouldl you need charge balancing circuits when you connect two such batteries in series? \$\endgroup\$ – Peter Bennett Jul 22 '20 at 1:01
  • \$\begingroup\$ @PeterBennett Good question. This is necessary to prolong the lifetime of batteries that are series connected. It applies to all battery chemistries, not just lead acid. If you don't do it, one battery may end up becoming overcharged over time and another undercharged. You can read more about it here: eenewsautomotive.com/content/balancing-lead-acid-batteries \$\endgroup\$ – mr_js Jul 22 '20 at 10:46

voltage is doubled when connected in series, but amperage stays the same. When connected in parallel, amperage doubles but voltage stays the same. Wire 2 batteries parallel and then wire the other 2 the same. Then wire one set to the other set in series. Problem solved.

  • \$\begingroup\$ This does not answer OPs question. \$\endgroup\$ – winny Jul 21 '20 at 8:37

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