My Screwy 31
First off let me say I am not stressing over this. It's just a battery, it is only money, it is meeting my overnight needs, but it is displaying strange behavior, and I am curious as to why. So th...
Forum Discussion
Mex must find this all so amusing :)
Solar is never going to exactly meet any battery manufacturer specific recommendation as it ramps up slowly.
When I wrote those last responses I was taking a break. I recharge my phone, crank up my fans, turn on the stereo. Open the fridge a bunch while I make lunch, flip open the laptop. It not as if those extra loads are going all daylight long. I do work.
Every time I've measured battery terminal voltage with a DMM and compared it to my battery monitor, the battery terminal is a few hundredths higher. I have 2 single decimal point voltmeters on my Dash wired directly to battery (+)'s. They are calibrated and follow both other voltmeters closely.
I realize I do not have enough solar to meet the minimum bulk current Spec of this battery. Attempting to meet Minimum bulk current is Why I reduced overall capacity and why I wired the system to run off either battery.
Usually by the time the sun is high enough for my 198 watts to be in the 13 amp range, the controller has already gone into acceptance and the amps are tapering and I start wasting solar electrons, yet I need more? I can't fit more.
Perhaps I should keep the solar off the depleted battery until 11 AM then switch all loads to the other battery just to barely meet the minimum recommended bulk current.
Too much effort on a daily basis,even if all it is is moving a couple switches.
I've been using 25 to 35 A/h per night lately. My solar, if the batteries were depleted enough to stay in bulk all day, could easily do 65 A/h this time of year and yes a small portion of that would be counted toward powering the small efficient compressor fridge and computer muffin fans, and whatever else I turn on during daylight.
This is about me trying to find the least aggressive solar settings which don't cause the SG of this specific battery to fall into the red after 2 weeks of cycling. I'm trying to not cause positive plate shedding by blasting it every freaking day with huge voltages in an attempt to get to 1.280 to make up for lack of initial bulk current.
If the battery only wants 1.5 amps to hold 15.3 volts what do you expect to happen when you force 10 amps into it at that point? Do you believe you can force 10 amps into it without voltage rising farther? I don't. The voltage would have to be risen to force 10 more amps into it.
Nothing is seriously amiss. It certainly is not perfect but As far as I'm concerned an 16v EQ cycle being needed every two weeks to bring the SG back upto 1.280 is hardly mind boggling nor reason to freak out and start taking things apart looking for issues. Especially since I've not yet been feeding it the USbattery recommended 15.3v finishing charge. That lack of 15.3 was mostly in deference to the AGM which I would allow to take part in the 14.4v+ come midday, but no longer do.
About this battery falling to voltage lower than hoped under relatively light loading for capacity removed, well my basis for initial comparison was a battery bank with 100 more amp hours, and now comparison is with a High quality AGM battery. So yea it does appear to be a loser, and it might very well be, but I am not going to rush out and get something else while this one still easily meets my needs.
And the Voltage does rebound fairly significantly in a few hours if I do remove all loads.
And it is just a battery They are just rented anyway. When this 31 no longer meets my needs I'll probably splurge on another Northstar AGM, if this one keeps performing admirably at that point.
Solar is never going to exactly meet any battery manufacturer specific recommendation as it ramps up slowly.
When I wrote those last responses I was taking a break. I recharge my phone, crank up my fans, turn on the stereo. Open the fridge a bunch while I make lunch, flip open the laptop. It not as if those extra loads are going all daylight long. I do work.
Every time I've measured battery terminal voltage with a DMM and compared it to my battery monitor, the battery terminal is a few hundredths higher. I have 2 single decimal point voltmeters on my Dash wired directly to battery (+)'s. They are calibrated and follow both other voltmeters closely.
I realize I do not have enough solar to meet the minimum bulk current Spec of this battery. Attempting to meet Minimum bulk current is Why I reduced overall capacity and why I wired the system to run off either battery.
Usually by the time the sun is high enough for my 198 watts to be in the 13 amp range, the controller has already gone into acceptance and the amps are tapering and I start wasting solar electrons, yet I need more? I can't fit more.
Perhaps I should keep the solar off the depleted battery until 11 AM then switch all loads to the other battery just to barely meet the minimum recommended bulk current.
Too much effort on a daily basis,even if all it is is moving a couple switches.
I've been using 25 to 35 A/h per night lately. My solar, if the batteries were depleted enough to stay in bulk all day, could easily do 65 A/h this time of year and yes a small portion of that would be counted toward powering the small efficient compressor fridge and computer muffin fans, and whatever else I turn on during daylight.
This is about me trying to find the least aggressive solar settings which don't cause the SG of this specific battery to fall into the red after 2 weeks of cycling. I'm trying to not cause positive plate shedding by blasting it every freaking day with huge voltages in an attempt to get to 1.280 to make up for lack of initial bulk current.
If the battery only wants 1.5 amps to hold 15.3 volts what do you expect to happen when you force 10 amps into it at that point? Do you believe you can force 10 amps into it without voltage rising farther? I don't. The voltage would have to be risen to force 10 more amps into it.
Nothing is seriously amiss. It certainly is not perfect but As far as I'm concerned an 16v EQ cycle being needed every two weeks to bring the SG back upto 1.280 is hardly mind boggling nor reason to freak out and start taking things apart looking for issues. Especially since I've not yet been feeding it the USbattery recommended 15.3v finishing charge. That lack of 15.3 was mostly in deference to the AGM which I would allow to take part in the 14.4v+ come midday, but no longer do.
About this battery falling to voltage lower than hoped under relatively light loading for capacity removed, well my basis for initial comparison was a battery bank with 100 more amp hours, and now comparison is with a High quality AGM battery. So yea it does appear to be a loser, and it might very well be, but I am not going to rush out and get something else while this one still easily meets my needs.
And the Voltage does rebound fairly significantly in a few hours if I do remove all loads.
And it is just a battery They are just rented anyway. When this 31 no longer meets my needs I'll probably splurge on another Northstar AGM, if this one keeps performing admirably at that point.
