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I might give up on LiFePo4

Pappion

Pappion

Retired Engineer Tech
Joined
Nov 26, 2020
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Having problems finding decent LiFePo4 for less than Battle Born. Having problems find reviews too. When Will gives a positive review the supply dries up.
SOK 206AH x2 order was cancelled by amazon.
I am even looking at DIY build, LiitoKala 3.2V 280Ah lifepo4, but can't find decent review. DIY with Overkill BMS. Also don't have top balance hardware.
liitokala at amazon overkill bms
I might just go with the Firefly Oasis Carbon Foam AGM. They say it has lithium performance DOD, fast charging, and wide temperature range -20c - 50c. BUT it still has a peukert effect and is a heavy 74lbs. I wanted 400AH Li but at this weight will only buy 200AH of these and have less reserve days. These are very popular with boaters.
Firefly Oasis
 
There is nothing wrong with AGM for low power use applications. My small camper has AGM, i have 4 other systems that use LiFePO4.

I’d recommend AGM for less than 2kwh/day, and less than 1kw inverter.
 
There seem to be limited purchase options for the Firefly Oasis Carbon Foam AGM battery. The delivered prices I found were over 50% more than a premium AGM battery of similar but greater capacity. The limited number of Amazon reviews are mixed.

The manufacturer warranty contains several interesting caveats.

"The warranty does not cover a battery reaching its normal end of life, which may occur prior to the warranty periods stated below. Depending on the application, a Battery can reach its normal end of life before the end of the warranty period. Normal end of life is limited to a fixed number of usable amp-hours a Battery is capable of delivering over its lifetime and under rare, heavy-cycling conditions may use up all of these amp-hours regardless of the time the Battery has been in service. Therefore Manufacturer reserves the right to deny a warranty claim if it determines the Battery to be at its normal end of life, even if the claim is lodged within the applicable warranty period."

Warranty Period Group 31 Oasis, RV/Marine Application - 24 Month Free Replacement, 48 Month Pro-Rated Credit Period, 6 Years Total.

"The Warranty Period will be reduced if average operating temperatures exceed 80°F (27°C), as follows: the Warranty Period will be reduced by 50% for every 15°F ( 10°C ) of prolonged operating temperatures over 80°F, excluding starting applications."

Source: https://www.emarineinc.com/Shared/pdf/Battery/Firefly-Oasis-12VG31-Battery-Warranty.pdf
 
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gecko said:
There seems to be limited purchase options for the Firefly Oasis Carbon Foam AGM battery. The delivered prices I found were over 60% more than a premium AGM battery of similar or greater capacity. The limited number of Amazon reviews are mixed.

The manufacturer warranty contains several interesting caveats.

"The warranty does not cover a battery reaching its normal end of life, which may occur prior to the warranty periods stated below. Depending on the application, a Battery can reach its normal end of life before the end of the warranty period. Normal end of life is limited to a fixed number of usable amp-hours a Battery is capable of delivering over its lifetime and under rare, heavy-cycling conditions may use up all of these amp-hours regardless of the time the Battery has been in service. Therefore Manufacturer reserves the right to deny a warranty claim if it determines the Battery to be at its normal end of life, even if the claim is lodged within the applicable warranty period."

Warranty Period Group 31 Oasis, RV/Marine Application - 24 Month Free Replacement, 48 Month Pro-Rated Credit Period, 6 Years Total.

"The Warranty Period will be reduced if average operating temperatures exceed 80°F (27°C), as follows: the Warranty Period will be reduced by 50% for every 15°F ( 10°C ) of prolonged operating temperatures over 80°F, excluding starting applications."

Source: https://www.emarineinc.com/Shared/pdf/Battery/Firefly-Oasis-12VG31-Battery-Warranty.pdf
Click to expand...
Ouch, warranty reduced for for over 80f. Not for AZ or other southern states.
 
I had planned on upgrading to lithium about 12 months after I brought my camper online, but I am rethinking this. I’ve been pretty happy with my four 6 volt golf cart trojan’s. I have no idea how long they’ll last, but I do take good care of them, so hopefully five years.
 
Talk to Michael on this forum. Lots of people had good luck through him.
diysolarforum.com

Lishen 270ah-272ah cell group buy.

Ok, this will be a longish post but I want to lay some foundation before taking orders on these cells. Eve 280ah cells appear to only be available at this point from suppliers that want a premium price for them From everything I can find, Lishen is extremely popular in China but has yet to get...
diysolarforum.com diysolarforum.com
 
Your firefly has reviews split between 1 star and 5 star.

Lead-acid batteries get hot during charging. They are only 70% efficient (more or less) so that's a lot of heat. If charging at a high rate, thermostatic fan should help keep them closer to ambient temperature.

Here's the AGM battery I use. It will cost you about $350 not $550 for one of that capacity.

Sun Xtender Solar Batteries - Photovoltaic Battery

The Sun Xtender Battery line consists of specialty lead-acid solar, photovoltaic batteries, and renewable energy storage batteries manufactured by Concorde Battery Corporation.
sunxtender.com
 
Concorde Battery manufactures both Sun Xtender deep cycle AGM batteries and Lifeline Marine & RV deep cycle AGM batteries.

A range of Sun Xtender and Lifeline battery sizes are readily avilable online at similar sizes, weights and prices. I found the Lifeline GPL-27T 12v 100AH Deep Cycle Battery and the Sun Xtender PVX-1040T 104AH Deep Cycle Battery both for $329.99 each with free shipping. However, there are differences in the manufacturer warranty for each series of batteries.

It appears Sun Xtender® AGM batteries have been specifically designed for fixed systems such as grid tied systems, off grid energy systems, energy storage systems for backup power, solar street lights and smart grid energy systems applications.

It appears Lifeline Marine & RV AGM batteries are specifically marketed for marine and recreational vehicle (RV) applications.

The Concorde manufacturer warranty for Sun Xtender batteries provides "full warranty credit for the battery or a replacement battery, at Concorde's option," for "365 days (12 months)". No extended pro-rated warranty is stated.

Source: http://sunxtender.com/pdfs/Sun Xtender Limited Warranty 6331-WT.pdf

The Concorde warranty for Lifeline (Marine & RV application) batteries provides "12 free replacement months" and "60 pro-rate months".

Source: https://lifelinebatteries.com/mcm_resources/lifeline-battery-limited-warranty/
 
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Hedges said:
Here's the AGM battery I use. It will cost you about $350 not $550 for one of that capacity.
Click to expand...
I already have FLA, but I really like these AGMs. Especially the higher AH rating at the lower volts. I like the idea of a 2 volt 600+ AH at the 20 hour rate battery. I just put six of these in Parallel, and I'm at 12 volts.

I had found 2 volt batteries, but these were odd sizes, which made getting cases for them impossible. I needed cases for my FLAs to add a vent. Don't really need a vent for an AGM battery, until they're at the end of there life and then they could start to vent.

Putting together a case and vent system took me about 2 weeks of searching to find something for my golf cart tall, 6 volt battery class GC2H. I solved it, but I would have liked a standard sized battery option where all the parts would have been easy to find and I did not need to go to so many stores to measure their boxes, order things on line to see that they don't fit and return them.
 
In my camper van I need a battery that can reliably handle charging day after day during a temperature range of -10° F to 105° F. I currently have a single Lifeline 12v 100 AH AGM battery which has served my needs well year round for the last four years. I don't use a large bank of batteries or power inverter. Battery weight or size of a single house battery in a van is not an issue.

If I ever needed more capacity I could purchase a Lifeline 150 AH AGM Battery for $469.95 twice and still spend $100 less than the Battle Born 12V 100 Ah LiFePO4 with the heated battery kit for $1,049.00. The usable amp hours are about the same assuming the sweet spot for an AGM battery is 50%-100% SoC and 10%/20%-90% SoC for LiFePo4. By using two consecutive Lifeline AGM batteries back to back the five year warranty coverage is the same as the ten year Battle Born warranty.

I realize there are cheaper LiFePo4 alternatives such as DIY used cell and Class B cell systems but there are also cheaper deep cycle lead acid batteries as well. If I am missing a benefit of LiFePo4 over AGM for a four season minimalist camper van, let me know.
 
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When I first made the jump into backup power systems I so wanted to upgrade the FLA batteries in my golf cart to Lithium. The cart is extensively used for driving, and is a self-propelled 48V battery pack for my off-grid inverter that back-feeds my breaker panel.

Then I learned about all the precautions and care that Lithium requires. Being in south TX cold weather protection was never an issue for me. However this week we were hit with frigid temps that froze the power plants and created rolling blackouts. The coldest day was 8F with a high of 20F so would have shutdown or trashed an expensive lithium battery set. The well-used and boring FLA batteries functioned without complaint.

Additionally my golf cart requires 130+ amps to accelerate and climb hills. At 48V that is one expensive lithium battery + BMS set. Four Battle Born in series won't do it. At this point I am very content to stay FLA.
 

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Delmar said:
The coldest day was 8F with a high of 20F so would have shutdown or trashed an expensive lithium battery set. The well-used and boring FLA batteries functioned without complaint.

At 48V that is one expensive lithium battery + BMS set. Four Battle Born in series won't do it. At this point I am very content to stay FLA.
Click to expand...

I question how much your run time actually increases with a small solar setup on the roof of a golf cart powering your house's panel. If you got say...12 hours of run time, how much would you have increased that to in the winter being able to charge at 8-20*F? 13 hours?

And what about overall capacity of lead being reduced in the cold, combined with the fact that you can't draw them down to near the lows of lifepo4?

Could get more than double (nearing on triple) the capacity of those battleborns for less than half the price with a DIY pack-with BMS.

But if you're content...
 
Any experience with these: Sio2

Lead Crystal / Silicon Dioxide Batteries (SiO2)​


  • No freezing. Higher temperature range with greater capacity than other batteries at low temperatures. -40C to +65C
  • Zero maintenance. No off-gassing. No acid spills. 1 year shelf life without charging.
  • Faster charging (.25C charge rate). 4 Hour charging vs. 7 Hours for lead acid.
  • Approx. 1/3 of lithium ion cost.
  • Long lasting up to 5 times longer than AGM batteries at 50% DoD (depth of discharge). Up to 7 x longer at 80% DoD. SiO2 batteries last to 16 years at 20% DoD.
  • Can be discharged repeatedly to 100% DoD with full recovery of capacity.
 
I think those are lead-acid (silica) Gel batteries.
But they do claim a relatively high 0.25C charge rate. Which my AGM can take.
I suspect it represents advancement in marketing
 
hour said:
I question how much your run time actually increases with a small solar setup on the roof of a golf cart powering your house's panel. If you got say...12 hours of run time, how much would you have increased that to in the winter being able to charge at 8-20*F? 13 hours?

And what about overall capacity of lead being reduced in the cold, combined with the fact that you can't draw them down to near the lows of lifepo4?

Could get more than double (nearing on triple) the capacity of those battleborns for less than half the price with a DIY pack-with BMS.

But if you're content...
Click to expand...
I'm in the Houston area so get lots of sun. The system was originally built for summer hurricane grid-down and I never expected this kind of cold weather. During the previous mid-40sF cold spell, in bright sun, I measured a peak 400W from the 400W panels.

Additionally I supplement the solar panels with the wall charger. The rolling blackouts were around 10 hours off and 16 hours on which gave me ample time to recharge. Running the usual lights, TV and computers would normally draw around 1000W, and cycling the furnace was around 2000W. With the combination of wall charging and solar panels the FLA easily lasted the required 10 hours. Mission accomplished.

Wouldn’t the BMS's on the Battle Born’s shutoff at 8F? Regardless four in series would not give me the needed 130+A to accelerate the cart.
 
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