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
Niner, trojan's group 31, the link you posted, was what I was going to go for for a direct performance, and longevity comparison, to the screwy 31.
But, It is still the car jar compromise. The T-1275 would appear to be the smallest of the real deep cycle batteries available.
Trojans 31 terminal placement would also likely have needed modification to accommodate height, and the extra 1/2 inch on the length on each side for the handles could have posed a fitment issue requiring one of them be ground off.
The place where I can get either trojan, lists both the 31 and the 1275 at the same price, 175$
As far as I am concerned, the 31 is not an option. the t1275 will be made to fit, and will have protection from engine compartment heat.
Regarding terminal placement, the (+) goes deepest. The (-) will be closest to the hood closing. Individual caps would be better for Fitment purposes rather than the ganged 3 caps, but no configuration is going to allow easy watering or SG checking of the 3 distant cells. There is no other location possible for a real battery. It IS going here. My underfloor tray where my single 27AGM now resides, can fit two 27's, and nothing taller than 9.5 inches.
The battery basically has to be removed for getting access to the three cells. I turn a few 1/2/both/off switches, remove tie down hardware, pull the ground cable off, lift and angle the battery and slide it out a bit, pull of the positive cable, and the battery can be removed entirely, or balanced precariously on the edge of the structure.
This is how it will have to be with the larger heavier t1275 too.
Now an Hydrometer extension tube is possible, and a better method to check level rather than a flashlight and a mirror for the 3 furthest cells could also be pondered.
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I cycled my 91AH NS AGM to 50% last night at a rate peukert would come in to play. 6.8 amps to 11 amps from 9PM to 2:30AM. When laptop was shut down, battery monitor read 46AH from full, and voltage rebounded to 12.2v instantly. I switched my Solar off, and when I awoke I turned it back on and plugged in the Meanwell and dialed that upto 14.5v.
It has been taking 45 to 52 amps for 20 minutes depending on cloud cover, for over 20 minutes now. Voltage is still 13.9v.
I've not really cycled the AGM deeply nor paid attention to its voltage during discharge those times when I did cycle it, but it appears to still perform well and apparently above spec. It is the same age as the screwy 31, but only has 30 to 45 cycles on it. Mostly it is an engine cranker, and my engine rarely takes more than 3/4 second to start.
This AGM gobbles up high charging amps like a woman in a shoe store and a daddy warbucks credit card
But, It is still the car jar compromise. The T-1275 would appear to be the smallest of the real deep cycle batteries available.
Trojans 31 terminal placement would also likely have needed modification to accommodate height, and the extra 1/2 inch on the length on each side for the handles could have posed a fitment issue requiring one of them be ground off.
The place where I can get either trojan, lists both the 31 and the 1275 at the same price, 175$
As far as I am concerned, the 31 is not an option. the t1275 will be made to fit, and will have protection from engine compartment heat.
Regarding terminal placement, the (+) goes deepest. The (-) will be closest to the hood closing. Individual caps would be better for Fitment purposes rather than the ganged 3 caps, but no configuration is going to allow easy watering or SG checking of the 3 distant cells. There is no other location possible for a real battery. It IS going here. My underfloor tray where my single 27AGM now resides, can fit two 27's, and nothing taller than 9.5 inches.
The battery basically has to be removed for getting access to the three cells. I turn a few 1/2/both/off switches, remove tie down hardware, pull the ground cable off, lift and angle the battery and slide it out a bit, pull of the positive cable, and the battery can be removed entirely, or balanced precariously on the edge of the structure.
This is how it will have to be with the larger heavier t1275 too.
Now an Hydrometer extension tube is possible, and a better method to check level rather than a flashlight and a mirror for the 3 furthest cells could also be pondered.
-----
I cycled my 91AH NS AGM to 50% last night at a rate peukert would come in to play. 6.8 amps to 11 amps from 9PM to 2:30AM. When laptop was shut down, battery monitor read 46AH from full, and voltage rebounded to 12.2v instantly. I switched my Solar off, and when I awoke I turned it back on and plugged in the Meanwell and dialed that upto 14.5v.
It has been taking 45 to 52 amps for 20 minutes depending on cloud cover, for over 20 minutes now. Voltage is still 13.9v.
I've not really cycled the AGM deeply nor paid attention to its voltage during discharge those times when I did cycle it, but it appears to still perform well and apparently above spec. It is the same age as the screwy 31, but only has 30 to 45 cycles on it. Mostly it is an engine cranker, and my engine rarely takes more than 3/4 second to start.
This AGM gobbles up high charging amps like a woman in a shoe store and a daddy warbucks credit card
