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02-17-2014, 02:01 PM
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Join Date: Dec 2011
Location: Kirkland, WA
Posts: 886
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Quote:
Originally Posted by Jackm
Shoria recommends a max charge rate of 8 amps to our LFX18. We installed a Sterling product unit to limit charge to 3amps since this is our backup battery only. Reason we did this is to compile amp limmitter, reversed feed diode and over voltage protection all in one package. What are you guys experiencing on battery's wired direct into charging system? Is that something we should be concerned about or is the high rate of charge only short lived?
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I'm curious about this too... What happens when my 60amp alternator dumps all the amperage the battery will take into it?
Last edited by grayforge : 02-17-2014 at 02:04 PM.
Reason: added quote for context
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02-17-2014, 02:05 PM
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Join Date: Dec 2007
Location: Puget Sound Area, WA
Posts: 220
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I looked on the Shorai website and looked at the different batts to find one with the highest Max Charge Rate(A). The highest I could find was 18A. Many are way below that. Not all of their batts had the specs, but at least a good indicator.
I'm basically a novice at this, but I concerned that a 40A or 60A Alt could fry the Batt or the circuitry (smart charge batts) if you had low voltage, but were still able to start your engine (barely) and your Alt kicks in to charge the batt.
See my previous post on what happened to me at Osh2012. What would have happen to me if I had a Shorai or any other LiFePo batt, especially ones out there with the "smart charge circuitry" when my 60A Alt kicked into overdrive?
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02-17-2014, 05:01 PM
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Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,692
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Quote:
Originally Posted by Mike S
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Thank you Mike (for the link) and Terry (for causing the question to form).
I was erroneously thinking that LiPo was poor shorthand for LiFePO4. I see now it is not. Thanks again.
__________________
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 850 hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.
Yeah. The boss got a Silhouette Cameo 4 Xmas 2019.
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02-17-2014, 06:20 PM
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Join Date: Jul 2011
Location: Ponte Vedra, FL
Posts: 36
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Quote:
Originally Posted by rzbill
Thank you Mike (for the link) and Terry (for causing the question to form).
I was erroneously thinking that LiPo was poor shorthand for LiFePO4. I see now it is not. Thanks again.
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Glad to help. LiPo and LiFePo are definitely different animals. LiFePo batteries are very stable and provide incredible power for there size. As for charging, a lithium based battery has a max charge rate in term of "C". The C rating of a specific battery is based on its output. So, if a battery is rated for 100 Amp hours and has a C rating of 10 it can be charged at a maximum of 10 amps. "C" , is a percentage of output capacity. If a LiFePo battery is not protected with internal manager/balancer it can be easily overcharged. LiFePo require constant current variable voltage charges. An alternator won't do it. They are constant voltage variable current. Not compatible in my book. 
If you haven't noticed most of the LiFePo battery venders offer special chargers if there units are not internally managed. 
__________________
I'M NOT SPEEDING...I'M QUALIFYING.
Terry Peterson
Last edited by TangoPapa : 02-18-2014 at 05:10 AM.
Reason: Error in the wording.
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02-17-2014, 06:34 PM
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Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
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Quote:
Originally Posted by TangoPapa
An alternator won't do it. They are constant voltage variable current. Not compatible in my book. 
If you haven't noticed most of the LiFePo battery venders offer special chargers if there units are not internally managed. 
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This is incorrect, or at least only partially accurate given that even vendors with a BMC offer chargers.
While Shorai and others do sell balancing chargers, they specifically state that alternators will in fact charge the batteries. Shorai recommends doing so once per year; the condition inspection is a great time to do this. The rest of the time, the alternator keeps it charged just fine.
Empirically, I have 30+ hours on a Shorai LiFePo battery in my RV and it has yet to be attached to the balancing charger.
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
Last edited by ChiefPilot : 02-17-2014 at 06:42 PM.
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02-17-2014, 06:56 PM
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Join Date: Sep 2007
Location: Central IL
Posts: 5,516
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Quote:
Originally Posted by kbehrent
I looked on the Shorai website and looked at the different batts to find one with the highest Max Charge Rate(A). The highest I could find was 18A. Many are way below that. Not all of their batts had the specs, but at least a good indicator.
I'm basically a novice at this, but I concerned that a 40A or 60A Alt could fry the Batt or the circuitry (smart charge batts) if you had low voltage, but were still able to start your engine (barely) and your Alt kicks in to charge the batt.
See my previous post on what happened to me at Osh2012. What would have happen to me if I had a Shorai or any other LiFePo batt, especially ones out there with the "smart charge circuitry" when my 60A Alt kicked into overdrive?
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It would do some good to look at this site to learn about C rate for Li batteries. This is a basic standard rate for charge or discharge. A battery can operate at a higher C rate, but the base should be known to set some boundaries for charge limits. http://batteryuniversity.com/learn/a..._is_the_c_rate
There is much more on that site about internal resistance too. PbA batteries have a higher internal resistance than LiXXX chemistries. That greatly helps the self discharge rate, and internal heating with high amps (charge or discharge)
Learning about new technologies is fun, as long as safety is maintained.
__________________
Bill
RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
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02-17-2014, 07:11 PM
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Join Date: Dec 2009
Location: Jupiter FL.
Posts: 451
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I have 100 hrs on my 3.1lbs Ballistic battery. I've only used a $30 charger from Ace Hardware made for riding lawn tractors. I only use the charger after long hangar times powered up. These batteries do not seem to trickle down like traditional Lead acid.
I have noticed that when the temp drops below 50F degrees volts read low initially (12.4ish). Normally it reads 12.8volts before start at all other higher temps. Regardless of Volt readings, starter engaged slings the prop just the same. (others have talked about these batteries need to warm/wake up at the lower temps by putting on elec loads)
100hrs and A LOT of start n stop operations with Young Eagle flights. The little 3.1lbs power source really slings the prop and hasn't let me down yet.
Hope that helps add to the data on this thread.
__________________
VAF DUES 7/13, 12/13, 03/14
Founder/Director
www.Aircraftwraps.com
Replace paint with performance.
This is my personal account and does not reflect the official communications of Aircraftwraps.com. We have retained a username for such correspondence. I post about formation, eating, aerobatics and pilot stuff  .
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02-17-2014, 07:29 PM
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Join Date: Jul 2011
Location: Ponte Vedra, FL
Posts: 36
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[quote=ChiefPilot;854932]This is incorrect, or at least only partially accurate given that even vendors with a BMC offer chargers.
While Shorai and others do sell balancing chargers, they specifically state that alternators will in fact charge the batteries. Shorai recommends doing so once per year; the condition inspection is a great time to do this. The rest of the time, the alternator keeps it charged just fine.
Don't get me wrong. I'm not saying it can't be done. Charging straight from the alternator is not optimal and has some risk. Excess charge is dissipated from the battery as heat. If two LiFePo batteries were put in a side by side test, one with a BMS and one without. My money is on the one with the BMS. It will live longer and provide better service.
I like the stats on this battery.
http://earthxmotorsports.com/our-batteries/
__________________
I'M NOT SPEEDING...I'M QUALIFYING.
Terry Peterson
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02-25-2014, 03:57 PM
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Join Date: Feb 2014
Location: Windsor, CO
Posts: 257
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Going to try and answer questions from the horses mouth
Thank you all who have purchased the EarthX lithium batteries for your airplanes and as many of you have asked us to go on this forum, I am going to attempt to be a resource here. Thank you Russ for helping out with the registration questions!! I am not an expert by any means on aircraft and our main focus and expertise has been of starter batteries for the power sport industry, but that being said, the aircraft market found us and will make us an expert in this field as well. I thank you all in advance! I am an expert on batteries though and if I can be of assistance, I will do my best to answer your questions. We are not a certified aircraft battery and should be only used in experimental aircraft (see, I am catching on already to the aircraft world...). I look forward to your questions. Kathy
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02-25-2014, 04:06 PM
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Senior Curmudgeon
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Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
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Welcome to VAF!
Kathy, welcome to VAF------the best site on the planet for things RVish
Good to have the support of another vendor.
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011 
Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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