Absorb times...

Started by alyaz, April 10, 2019, 08:31:19 PM

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mike90045

As to setting off CO detectors - why are batteries inside the house, and not in a box or outbuilding with proper venting ?
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

Vic

#16
Hi Tim,

Since you have Flooded LA batteries,  you can use your high quality Hydrometer to actually MEASURE your SGs,   as the charge progresses.

SIX hours of Absorb is a very,   very,   very long time,  unless the battery is taken to somewhere around 50% SOC,  in normal use.

60 V Abs IS high,   unless Surrette has changed to Lead-Selenium-Antimony construction.

The Surrette FLA banks here use Abs voltages of about 58.3 - 58.5 V,   and Absorb times of about 2.25 hours,   on average.

Shunt EA settings of about 0.9%-1.6% of actual 20 hr Capacity.   All of these battery banks are in their 14th year,   so Abs voltage  and EA settings have increased,   somewhat over their lives.

To me,   the Surrette Formula for Absorb time is useless for systems that are charged from off-grid PVs.   IMO,   that formula is for grid-powered chargers and constant current charging.

More info on your system would be helpful,   and the Ah removed from the batteries on the average cycle,   etc.

Just opinions,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
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