Author Topic: Absorb times...  (Read 2051 times)


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Re: Absorb times...
« Reply #15 on: June 03, 2019, 02:31:51 AM »
As to setting off CO detectors - why are batteries inside the house, and not in a box or outbuilding with proper venting ?

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


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Re: Absorb times...
« Reply #16 on: June 03, 2019, 10:10:10 AM »
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
« Last Edit: June 03, 2019, 10:11:52 AM by Vic »
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!