Trojan t-1275 vs Signature series J150 RE
Before winter, I need to get a dedicated flooded house battery, my Northstar AGM-27 has been working hard as both house and engine battery for the last 4 months, and I want to return it to engine star...
Forum Discussion
End of life at 50% rated AH is not based on reality. Most folks would say it is when they can't get through to the next scheduled recharge time.
Say you have two 6s at 232AH and use 70AH a day and you need them to stay above 50% so the inverter won't alarm off under load. So you need the capacity to be at least 140AH. That is 140/232 = 60%.
So somewhere before they get to 60%, you will want to replace them. Besides that, the usual story is that they will hold fairly well until they don't, when they decline rapidly.
So you have to watch for that, and replace them at 70% if you need 60% minimum, or get caught short while out camping with several days of camping still to go.
---Mex, I have a standard $6.00 glass bobber hydrometer that is good enough for my purposes. It is consistent for comparison work.
I don't know what the original SG was in these batteries. 1.300 was reported by an Interstate battery guy to be the new standard for their 6s ten years ago, but I have no idea if he had that right or just a rumour. Also I don't know if these were of the "northern standard" when we are in the "temperate zone". I would think where Mex is the SG would be to tropical zone for hot temps, but that depends on just where in any zone you live for what really happens there.
Anyway, I don't care if they die too soon. They were free to me and are doing great, so if they have all the battery diseases known to man, and will collapse anytime soon without warning-- too bad, so sad! :) Actually, I get the feeling they will last a long time from how things are going so far.
Say you have two 6s at 232AH and use 70AH a day and you need them to stay above 50% so the inverter won't alarm off under load. So you need the capacity to be at least 140AH. That is 140/232 = 60%.
So somewhere before they get to 60%, you will want to replace them. Besides that, the usual story is that they will hold fairly well until they don't, when they decline rapidly.
So you have to watch for that, and replace them at 70% if you need 60% minimum, or get caught short while out camping with several days of camping still to go.
---Mex, I have a standard $6.00 glass bobber hydrometer that is good enough for my purposes. It is consistent for comparison work.
I don't know what the original SG was in these batteries. 1.300 was reported by an Interstate battery guy to be the new standard for their 6s ten years ago, but I have no idea if he had that right or just a rumour. Also I don't know if these were of the "northern standard" when we are in the "temperate zone". I would think where Mex is the SG would be to tropical zone for hot temps, but that depends on just where in any zone you live for what really happens there.
Anyway, I don't care if they die too soon. They were free to me and are doing great, so if they have all the battery diseases known to man, and will collapse anytime soon without warning-- too bad, so sad! :) Actually, I get the feeling they will last a long time from how things are going so far.
