Truth about Lead Acid Battery Capacity

john61ct

Adventurer
Did you wtach the video? None of the FLA/AGM meet your 80% professional or 70% non critical SOC when brand new so there's no way they'll do it after 10 years.
Nothing to do with SoC.

And yes they do, you might have misunderstood.

I know my text style is dense, and I have left out a lot of details.

I'd be happy to clarify if you (or anyone) wants to ask specific questions,

I just do not want to appear pointlessly argumentative
 

john61ct

Adventurer
Dual purpose batteries are like tires that are made to use when it's 110F in the summer and 20F in the winter.
There are some fantastic ones from those top few vendors, but not cheap.

Also not necessary, since a good House bank of any size will out-crank a smaller Starter every time.

And for winching, windlass etc high amp loads, you need to be running your alt in support anyway.
 

67cj5

Man On a Mission
Dual purpose batteries are like tires that are made to use when it's 110F in the summer and 20F in the winter.
Yeah thats according to US Specs, Mine are Rated to UK/EU Specs which are Tested at 0*f or -17.8*c,
 

67cj5

Man On a Mission
What brand?
These Batteries are made According to American Specs, If you read the Info and the specs they say it can be discharged up to 70% and in the specs below it says it has a 600 cycle life, I bought mine I think it was in June 18th 2017.

Hope that helps.

 

Hilldweller

SE Expedition Society
I used to get premium batteries at employee pricing. I'd run two 100ah (give or take) AGMs and try to keep them up with 100w solar. Replace every two years or so.
Got old. Then expensive without the employee pricing.
Doing much better now with 100ah LiFePo4 battery and 200w solar. Easy button. No fuss at all.
sigh
 

67cj5

Man On a Mission
I used to get premium batteries at employee pricing. I'd run two 100ah (give or take) AGMs and try to keep them up with 100w solar. Replace every two years or so.
Got old. Then expensive without the employee pricing.
Doing much better now with 100ah LiFePo4 battery and 200w solar. Easy button. No fuss at all.
sigh
A lot of people rage about AGM, I just don't like em, My Lead Acid Batteries posted above have higher Voltage and I can run my ARB Fridge in Freezer mode for a good 24 hours before the voltage even reaches 12.7v, And using Smart Chargers for AGM Batteries is a pain because they have a set way of doing things where as Lead Acid is more switch on and get it done. In 5 months my Lead Acid Batteries will be 5 years old, and when looked after they last a long time,

Doing the Maths, I paid at the time £100.00 for one at about $1.31c per GBP, That works out to be $26.20c per Year over 5 years, My Last Battery was just under 10 years old and I Killed it in the end so I could of got over 12 years out of it. If these ones last the same amount of time The cost per Year could work out to be under $10.91c per year.
 

67cj5

Man On a Mission
Here's the Reciept,
Invoice
  • Order Number 28465
  • Order Date July 18, 2017
  • Payment Method


ProductPriceQuantityTotal
Advanced XD31 Dual Purpose Leisure Battery 115ah
SKU: ABS-XD31
£100.00 1 £100.00
Subtotal£100.00
ShippingFree Shipping
Total1£100.00 (includes £16.67 VAT)
 

67cj5

Man On a Mission
egads, they charge you guys VAT on everything...
Yeah they have since put it up to 20% for the last 3+ years, Heaven forbid If I import anything from the US, A friend sent me a T-shirt and although he paid the postage I had to then pay Import Duty @ 20% plus Postage, and they were based on the Cost of the Shirt add that to the cost of the Postage my Friend paid in the US to send it to me So that 15.00 Dollar Shirt ended up costing about 75 to 80 Bucks,

Thing is If the Shirt costs under £20.00 then they can't charge anything but if they add the cost of the US Postage my Friend paid to the Shirt that then takes it over the £20 limit so then they get to add all those extras On, I wouldn't mind But it was a Gift not something I had purchased, :mad:?? LOL.
 

Alloy

Well-known member
I used to get premium batteries at employee pricing. I'd run two 100ah (give or take) AGMs and try to keep them up with 100w solar. Replace every two years or so.
Got old. Then expensive without the employee pricing.
Doing much better now with 100ah LiFePo4 battery and 200w solar. Easy button. No fuss at all.
sigh

During my 30 days in the woods I spent a considerable amount of time trying to bring the FLA up to 100%. Each day the generator was running in float for 1-2 hours.
I just spent the last 4 days equalizing them and did a load test this morning. All it took was 210Ah to get down to 12.0V on a 4yo bank that was suppose to have 467 usable Ah.
A new FLA bank of 8-6V is $1,400.00CDN. Based on past experience I may get 300 usable Amp hours + all the hassle of trying to keep them at 100%.

For $1500CDN I can get 560 (8-280Ah cells) usable Lifepo4 amp hours from Alibaba. There will be allot of screwing for the install but I'll enjoy it.
 

67cj5

Man On a Mission
During my 30 days in the woods I spent a considerable amount of time trying to bring the FLA up to 100%. Each day the generator was running in float for 1-2 hours.
I just spent the last 4 days equalizing them and did a load test this morning. All it took was 210Ah to get down to 12.0V on a 4yo bank that was suppose to have 467 usable Ah.
A new FLA bank of 8-6V is $1,400.00CDN. Based on past experience I may get 300 usable Amp hours + all the hassle of trying to keep them at 100%.

For $1500CDN I can get 560 (8-280Ah cells) usable Lifepo4 amp hours from Alibaba. There will be allot of screwing for the install but I'll enjoy it.
Sounds like you need to desulphid your batteries, My batteries hold 13.4v for 24 hours after coming off the charger, What I do is charge them until they reach 14.8v and let them sit doing that for between 2 to 4 Hours and then I remove the Normal lead Acid charger and then I let the Noco G26000 charge them and once it runs through its way of charging it will then sit there making a quiet clicking sound that can take a few days on Badly sulphided Big Batteries and once it stops I run its Repair Mode which runs for 4 hours exactly and if a battery is doing what yours is I might run the Repair mode 2 or 3 times, And I will repeat all of the above for the next 3 or 4 Cycles of the battery, In the end they will come back good again,

If the battery has been sitting for 2 or 3 months or slowly discharged ect I will run the above process just to wake the battery up again, As I posted earlier my batteries are coming up to 5 years old in a few months and they will still hold 13.4v after 24 hours from being removed from the charger,

Try giving that a go and your batteries should come back to life again,

Good luck.
 

john61ct

Adventurer
During my 30 days in the woods I spent a considerable amount of time trying to bring the FLA up to 100%. Each day the generator was running in float for 1-2 hours.
Even the highest-Car (charge acceptance rate) lead battery used for deep cycling takes at least 7 hours to get back to true 100%.

This is true no matter how much current the charge source offers, making 500A available may get to 90% in an hour, but as amps pulled by the bank declines it will still take 6+ more hours to finish the job.

Fossil fuel charging is thus only efficient up to that 85-90% point, hugely wasteful after that unless using alternator while you had planned to be driving anyway.

The ideal is do that in the early morning, then use solar for "the long tail". Does not need to be the same watts you'd want in a solar-only setup if CAR has dropped to 0.1C a little 200W setup can handle a 1200Ah bank.

But YES the fact that LFP actually prefers sitting at PSOC rather than getting murdered by it is a fantastic advantage

almost as nice as fully refilling in under 2 hours with a high Amp source.

But you now need to ensure that House does NOT sit at Full for long

And ensure that it's incredibly high CAR doesn't burn out your charge source...
 

67cj5

Man On a Mission
Even the highest-Car (charge acceptance rate) lead battery used for deep cycling takes at least 7 hours to get back to true 100%.

This is true no matter how much current the charge source offers, making 500A available may get to 90% in an hour, but as amps pulled by the bank declines it will still take 6+ more hours to finish the job.

Fossil fuel charging is thus only efficient up to that 85-90% point, hugely wasteful after that unless using alternator while you had planned to be driving anyway.

The ideal is do that in the early morning, then use solar for "the long tail". Does not need to be the same watts you'd want in a solar-only setup if CAR has dropped to 0.1C a little 200W setup can handle a 1200Ah bank.

But YES the fact that LFP actually prefers sitting at PSOC rather than getting murdered by it is a fantastic advantage

almost as nice as fully refilling in under 2 hours with a high Amp source.

But you now need to ensure that House does NOT sit at Full for long

And ensure that it's incredibly high CAR doesn't burn out your charge source...
To charge Deep Cycle batteries properly using a Normal Charger charging 2x 115Ah batteries can take up to 27 hours or more at around 8 or 9A from a 50% SOC so charging monster batteries is going to take days, Because Deep Cycle Batteries don't like being beaten in to submission,

If I am trying to put the power back fairly quickly I charge them at around 16A and after 8 or 10 hours I drop the charge rate down to the 9A setting by this time that are accepting around 5A on this setting.
 

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