Lead acid 20% State of Charge

[hbn7hj]

"2018: Stop believing that lead acid batteries cannot be run below 50% without damage. It is 20%, using 80% of capacity. Will we ever be delivered from all of the idjits on forums who just repeat everything they heard?"

Since I'm low on battery bank, have voltage stabilizers and have been priced out of RV parks I think I'll see how the below 50% discharge works.

Will let you know.
Harry

[booster]

Originally Posted by hbn7hj

"2018: Stop believing that lead acid batteries cannot be run below 50% without damage. It is 20%, using 80% of capacity. Will we ever be delivered from all of the idjits on forums who just repeat everything they heard?"

Since I'm low on battery bank, have voltage stabilizers and have been priced out of RV parks I think I'll see how the below 50% discharge works.

Will let you know.
Harry

Cool quote, yours or is it from somewhere??

Seriously, I think there is very, very, little chance that the 50% rule is correct and the 20% rule is armageddon. I am risk aversive and am willing to risk $1200 worth of AGM batteries on that bet. I think Avanti will tell you the same for his similar AGM bank.

In reality, I think it has never been a big deal to go to 20%, but the issue in the past was knowing when you got to 20% so you didn't kill the batteries at empty. With all the current battery monitor availability it has pretty much eliminated that issue, so it is much easier to take the batteries lower without the extra risk of going to dead.

With the lithium sellers telling everyone their lead acid batteries will die instantly if they go more than 50% down, we crusaders will continue to be on the minority end of the opinion curve, I fear.

[Bruceper]

Yes it's 2018, but you're using technology from 1859. Sure it's been improved a little since then, but not enough to make a difference and there's 160 years of knowledge and research that says they suck. But they work, and that's why they're still around.

[booster]

Originally Posted by Bruceper

Yes it's 2018, but you're using technology from 1859. Sure it's been improved a little since then, but not enough to make a difference and there's 160 years of knowledge and research that says they suck. But they work, and that's why they're still around.

All true, but I would be willing to bet that for 130 of those 150 years, they discharged the batteries to 20% without concern

I think it is just recently that the battery marketing folks learned that by manipulating how the cycle life charts are presented, they could sell a lot more batteries, plus knowing that they would get killed off early anyway by poor charging and no one would know that they had bought more batteries than they needed.

[hbn7hj]

Not my thought. It belongs to:

https://handybobsolar.wordpress.com/...ad-this-first/

I don't intend to hit 20% but the observation that before battery monitors you couldn't tell where you were and couldn't get that close explains a lot.

The problem with low state of charge for most of us is modern electronics check out and inverters scream long before 50% state of charge.

The fridge will sign off at 9.6 volts so I will have to keep an eye on that. The voltage I see at the battery posts is less than the open circuit voltage that would indicate state of charge. I only have two 6 volt Trojans several years old at risk.

Satellite TV and DVD player is my current drain and I prefer to only run the generator in the morning. My summers are at 9000ft so I prefer not to choose between electronic entertainment and furnace.

I'll put a voltage stabilizer on the fridge and even the furnace if I have to.
Harry

[Bruceper]

Originally Posted by booster

All true, but I would be willing to bet that for 130 of those 150 years, they discharged the batteries to 20% without concern

I think it is just recently that the battery marketing folks learned that by manipulating how the cycle life charts are presented, they could sell a lot more batteries, plus knowing that they would get killed off early anyway by poor charging and no one would know that they had bought more batteries than they needed.

I do agree.