Originally Posted by Ex-Calif
Good on ya!
BTW - I am considering this monitor myself and have not found any real world description of the programming - Yes I can RTFM but I am interested to know if you found it confusing or daunting?
For an Ah counter to be accurate, you will need to know:
*Your banks ACTUAL PHYSICAL 20 hour Ah capacity at this current time. This requires a controlled 20 hour capacity test.
*Your banks average temperature (the BMV does not have a temp sensor)
*Your banks Peukert
*Your banks charge efficiency (how many Ah's out vs. in to get back to 100% SOC)...
For an Ah counter to be a good guide
* The closest approximation to your banks current physical capacity. (It will not be the rating
for very long) Programing for less than you assume
you actually have will always be safer..
* Your banks average temp
*Peukert (factory number fine)
With any Ah counter please do yourself a favor and dial out "auto reset".. I have not seen a single
one that works well and there are far too many variables that can trick them into resetting to 100% SOC well before the bank is actually at 100% SOC... These devices DO NOT reset on Ah's they reset on voltage, % current and time at both..
"Know full resets
" are the best way of keeping them in-line and should be done as often as possible when the bank is known full..
How do you determine known full
Is the bank accepting less than 1.5% of its Ah capacity at 14.4V+ (ABSORPTION VOLTAGE)? (14.1V for GEL) If yes, reset....
DO NOT do a known full reset
at float voltage! The batteries must be accepting less than 1.5% - 2% of Ah capacity at absorption voltage.
Ah counters are NOT plug
& play they are like dead reckoning and require human intervention to give accurate results. Far too many owners try and plug
and play with them, and for a couple of years it works to their advantage, then it tends to fall off the cliff......
Do not expect Ah's consummed to relate to SOC. It NEVER WILL!!!! Only the SOC screen
, with a PROPERLY programmed monitor, can do this because it takes Peukert, temp and other factors into consideration that the Ah's consumed screen
20 Hour Capacity Test (an Ah counter can be used to count the Ah's delivered):
Charge battery to 100% full
Let sit at 75-80F until the battery is at that temp
Apply a load = to the 20 hour rating tested load. This is Ah Capacity divided by 20. Eg:
100Ah / 20 = 5A
150Ah / 20 = 6.5A
225Ah / 20 = 11.25A
Hold load steady, adjust as needed, as voltage decays. Current will change as voltage falls. It needs to be held steady for the capacity test to be accurate.
Discontinue test as soon as battery terminals hit 10.5V
Count Ah's or count time. If less than 20 hours before hitting 10.5V what percentage of 20 hours did the bank deliver. If using an Ah counter how many Ah's before hitting 10.5V?
Recharge battery immediately at the 20 hour rate. Do not "fast charge it"...