Two Banks in One Cabinet

tcvb
tcvb Solar Expert Posts: 44
What do yall think of this kind of setup? Having two separate banks in one cabinet.One bank AGM's the other flooded.Having a switch between the two of them so you could alternate between banks.I understand your not supposed to have a switch in a flooded bank enclosure but if you ventilate it before you operate it would this be good?

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Two Banks in One Cabinet

    Could you not have the switch outside the box where there would be no chance of gas build up to be ignited?
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Two Banks in One Cabinet

    AND - you have to reprogram the charge controller for each type of battery when you switch. AGM & flooded have different charge regimes.

    AND you will have to power down the PV and then the controller BEFORE switching the batteries, or you risk "glitching" the controller when the switch Breaks before Make .
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Two Banks in One Cabinet
    mike95490 wrote: »
    AND you will have to power down the PV and then the controller BEFORE switching the batteries, or you risk "glitching" the controller when the switch Breaks before Make .

    AND if your switch Makes before Breaks, you may have quite a current flow (and pitting on the contacts) as the two batteries of different voltage are momentarily paralleled.

    What's the point (what are you trying to accomplish) of having two different battery banks on one system?

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Two Banks in One Cabinet

    Probably to have some back-up DC available in case things get too cloudy for too long. Having the charging system switch to the AGM bank (held in reserve) when the FLA bank is full could provide that power (AGM has lower self-discharge rate and so would be easier to maintain in readiness).

    But as pointed out the Voltages would be different. Yet since the AGM is lower it might be possible to use some simple method such as a diode to drop the charging Voltage and keep the bank full.

    On the whole it sounds like more trouble than it's worth. I've tried dual banks of the same type/size battery and found it to be so.