โSep-22-2019 06:06 PM
โSep-29-2019 12:09 PM
โSep-29-2019 05:40 AM
โSep-28-2019 10:54 PM
โSep-28-2019 05:56 PM
โSep-28-2019 05:04 PM
โSep-28-2019 04:31 PM
BFL13 wrote:
100lb AGMs sound like 4Ds Some of those can be 200AH, while my 8D at 150 lbs is rated 250AH. AGMs except Lifeline seem to have spec max charging at about 30% charging rate. So 50 amps on 150AH works.
I had the 100AH AGMS for a year before they got in this MH and for the two years since they have been recharged per Mex's rules (20% bulk, 0.5/100) The 8D was second hand so I don't have its history. It has worked ok for a year until this started.
It seems to arise from repeated high amp draws where heat must build up inside and warps or cracks the plates somewhat. One high amp run I can get away with, maybe--we'll learn more about that when next out camping.
The mix of 27s with these AGMs is a quick-fix attempt to get more time with these AGMs before I have to get a new battery set. One of these days I will have four new batteries all the same, and have no more trouble ๐
โSep-28-2019 03:24 PM
โSep-28-2019 03:17 PM
BFL13 wrote:
I do in fact adjust the charging voltage for temperature, so that when camping in February and ambient is 35F, I will set 15.2 instead of 14.7 as in July. The adjustable voltage PowerMax "LK" line of converters lets you do that manually.
My old VEC1093DBD portable charger has built in temperature comp and you can see it working when it operates at higher or lower voltages.
Neither compensates for battery internal temperature though, just ambient.
The AGM guides insist upon temp comp. If you set the spec 14.4 (for 77F) in February at 35F, you will be undercharging the AGM, with no way to see the SG failing to rise to the right amount.
โSep-28-2019 02:47 PM
BFL13 wrote:
...
--When doing my capacity testing with Wets at the 20 hr rate,
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โSep-28-2019 01:48 PM
โSep-28-2019 01:31 PM
BFL13 wrote:
I have always used the same voltage vs SOC at all ambient temperatures. Is that proper?
The AGM loses 15% capacity at freezing vs at rating temp of 77F, so is it still 13.0v when full? BUT at freezing temp, your charging rate of 14.8 is now supposed to be adjusted upwards to 15.2 volts to compensate for the cold. Voltage going opposite directions there maybe.
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โSep-28-2019 12:05 PM
โSep-27-2019 07:01 AM
โSep-27-2019 12:52 AM