Can I connect two 12 volt charge controllers to my 400 watt solar array?

I presently have a 12 volt 40 amp MPPT controller connected to a 12 volt 200 Ah lithium ion battery. I would like to connect a second 12 volt, 30 amp MWP charge controller that I have purchased and connect it to the same solar array in parallel and power two AGM batteries.

I hope this makes sense. I want to charge the second battery bank AGM separate from the lithium ion battery for obvious reasons (as you know, lithium ion doesn’t require a float etc.).

  • \$\begingroup\$ You can try... how well they share when both need charge is anybody's guess. But if your MWP charger is actually PWM, at least you don't have two MPPT algorithms fighting each other. \$\endgroup\$ – user_1818839 Mar 23 at 19:28
  • \$\begingroup\$ The lead acid batteries will probably charge first if the charger doesn't have MPPT. Up until they are close to charged they will probably pull output voltage below the maximum power point, making the other charger either not cut in due to insufficient voltage or limit to very low current because any increase will be detected as making the power point worse. Only after the non-MPPT charger input decreases enough for headroom on the max power point will the MPPT controller increase current. \$\endgroup\$ – K H Mar 24 at 2:36
  • \$\begingroup\$ Okay great thanks I believe you answered my question. Then I guess I will just get another PV for the PWM. Was looking at a 350 watt single panel from Canadian solar. I certainly wouldn’t want to damage any of the controllers. G. \$\endgroup\$ – Garry Kearns Mar 25 at 1:45

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