More Solar for "Us"
Ok, I went off.the deep end? Bought 3 used 37watt uni-solar panels and a blue sky 2000e controller for the hefty price of $400, They were being listed as 75w panels, they are not The tested open...
Forum Discussion
Salvo wrote:
That's a fair question. All modern multi-stage converters have an algorithm to prevent boiling. They are designed to reach the max boost voltage and then go into absorption mode (at a lower voltage level).
Never say "all." Vector , Xantrex and Deltran don't. The whole idea is to get to the threshold voltage and switch to constant voltage at that threshold while amps taper doing the absorption stage. In fact Deltran has now added a new stage after the absorption stage where they *increase* the voltage to 16v for a time before dropping into Float.
Lowering the voltage for the absorption stage would be crazy. That would make the battery acceptance rate less in amps and prolong the recharge time a bunch, defeating the whole objective of achieving the fastest (but safe) recharge time for that size battery bank.
They do limit the absorption stage though , because that could run for infinite time. They stop it around 97% SOC and THEN let the voltage drop to Float from Vabs.
Some limit Vabs to four hours. This does not matter if the battery bank will be recharged in that time anyway and go into Float, but IMO it is unsat for a larger bank and a low amp smart charger which might take longer than four hours to complete the absorption stage. (such as what Mr Wiz has with his bank and solar controller)
So with a four hour limit, just when you need the higher Vabs the most, near the end at the higher SOC with lower amps being accepted, the silly thing would get to four hours and drop the voltage on you! Ridiculous. Better not to have the time limit and just use the 97% SOC as the marker.
