I have 2 battery banks, both about 370 Amp Hours @ 24 V. I have them wired to the Classic by switching the positive lead from each of the banks via an A/B battery switch. The negative lead from the banks are common. My question is can I switch between the two banks without causing any charging sequence issues? When I switch banks I first power down the system, switch the battery bank, then power up the Classic. On power up, does the Classic evaluate the battery bank, then start a fresh charging sequence? Can this cause charging problems? Does it remember where it was in the charging cycle on a reboot from the previous battery and apply it to the newly switch battery?
I can not say for sure but, it seems if the Classic is powered down when you switch banks that it will start up from scratch and see the second bank as a fresh charge cycle.. No different than it being powered down for any reason. The input source voltage might keep the Classic alive so not sure on that bit
I think.
No guarantees.
Tom
When the Classic is powered down or is reset in any other way, the Classic will start from scratch.
This means it starts from BulkAbsorb with the full time left on the Absorb timers. So if you set the Classic
to Absorb for 2 hours, it will do that when it is powered up again. ....assuming there is enough
energy available or enough time left in the day to get the job done...
Quote from: boB on February 01, 2015, 10:33:09 PM
When the Classic is powered down or is reset in any other way, the Classic will start from scratch.
Is there a byte or two of eeprom available so that a few running values could be retained?
I'm thinking of the Energy Kw/hr as its most annoying when this resets to zero on a
reset in any other way event.
It would only need to be saved as it changes but would probably need time stamped so that if the Classic was restarted after a long off period, perhaps more than 30 minutes, it would reset this to zero.
dgd
Quote from: tropicalsolar on January 29, 2015, 08:37:11 PM
I have 2 battery banks, both about 370 Amp Hours @ 24 V. I have them wired to the Classic by switching the positive lead from each of the banks via an A/B battery switch.
Many of those battery switches are "make before break". In other words, both batteries are connected in parallel for a moment during the switch. This means you do not need to power down the classic.
If the batteries are at very different SOC, or if there are large loads or charging currents, there may be huge current flows through a "make before break" switch.
--vtMaps
If the Classic is running when you change batteries, even if it is break before make, it will usually
stay on. In fact, if it is in Absorb or Float, it will probably stay on for a while before going off.
You cannot count on SOLAR mode staying on if in BULK MPPT mode though because the Classic
may sweep and turn itself off at that time unless you switch quick enough... BUT, sounds like
you WANT the Classic to start from scratch. Either that, or just go to TWEAKS and force
a BULK/ABSORB and that will make it start from scratch without having to actually repower
the Classic. Same effect. And then it will remember the Amp-Hours and kW-Hours etc.
Now, why is it that you do not want to just operate the two banks in parallel ?
As long as you can Absorb both of them connected together you should be fine...
Maybe if one bank is a LOT bigger than the other bank and it needs some different
amount of Absorb time, might be a reason to have two banks ?
boB