LiFePo4 Battery Usage

Excuse my ignorance. I'm going to assume it's dry.

NiCads should be fully charged and fully discharged over each cycle. Ni metal Hydrides, too.

Li ion likes a partial discharge, not full and should be charged slowly up to the full voltage level.

Check the net. There's ton's of opinions out there.

I was hoping to get a more scientific/engineering comment rather than manufacturer conservative anti-libel protect-the-consumer data or from the hip blog posts of urban myth best guesses.

Pardon me. I'm gone.

No, what you're clearly hoping for is someone who you think has an inside scoop on the top-secret sure-fire top-secret techno-magic method of getting absoulte maximum possible performance out of your exact battery model to break his/her code of silence and divulge it all in exquisite detail.

What you'll actually get here are rational answers based on the best info we have available. In this case lynlynch took a shot and answered at least one of your questions to the best of his ability with the limited info given. If you'll be so kind as to post both the battery and charger manufacturers' full data sheets so that we can look at the specifics of each, you might get an answer up to your high standards. But I wouldn't hold my breath.

Well...

some slightly more scientific reading for you to do...

https://www.sciencenews.org/articles/20020928/fob4.asp

Postscript: the more commonly recognized acronym for your equipment is simply 'LFP Battery'.

In trying to find out how this got all personal, I think I found the link.

Let me rephrase the response above; By posting on CR4 I am hoping for a more scientific/engineering response other than an assumed on my part "manufacturer conservative anti-libel protect-the-consumer data blah blah blah" response that I would recieve elsewhere on the WWW.

I'm sorry if anyone on CR4 interpreted I was critical of them & that their response was discounted or unappreciated. I was confused about being flipped off but then there you go. If I sound like an ass, again I apologize and appreciate your patience and grace.

If you expended time and effort to post this posting, why not add the type of battery you got and it's amp/h rating. How can you expect anyone to reply to your question without this information.

It's all there Loki, LiFePo4(lithium Iron Phosphate)=type; 20 amp hour= amp

_{Picture lynlynch slapping forehead with palm.}

No, Richard, with all due respect, it's not all there. Not everyone knows what "LiFePo4" means. One can only assume what it means and assumption is not knowledge. For this reason, the higher echelons of technocracy try not to use labels, acronyms or abreviations wherever possible.

As far as is known, Lithium batteries have no memory problems and lend themselfes to charging in any state. Important is to have a first class, top notch automatic charger, guaranteed not to overcharge a battery if left "ON" too long.

I would also suggest to take a closer look at advanced Lead-Acid batteries of suitable voltage and amp/h. Their total life time is slightly less than lithium, but they do excellent work and cost peanuts compared to the 500 bucks you mention.

No, with all due respect, if you don't know what Li=lithium; Fe=iron; Po=phosphate; represents in battery technology, your not up to date and should listen rather than talk. If you must make assumptions maybe again you should watch quietly while learning.

Remember I mentioned that this was for a bicycle? Lead=Heavy. LiFePo4=light. Heavy=Bad. Light=Good. Lead-acid must be recharged immediately after use, this makes it less viable as an alternative transportation to the automobile/motorcycle. Lead-acid also loses its capacity after as little as 300 rechargings. Lead and acid are both toxic to man and the environment. Lithium Iron Phosphate is the same technology used by Tesla Motors in it's Roadster.

Be nice, live long and prosper.

With all due respect (Which at this moment is getting near zero) If you chose to continue to be an arrogant, self centered, pompous windbag, spouting demeaning comments to the good people of this forum. You will be lucky to continue getting responses from any other qualified persons, who may have been able to answer your question.

I for one could give you the answer and settle your dilemma, however I choose not to thanks to you previous comments to genuine requests from other posters.

Consider that a polite slap on the wrist.

This guy is amazing.

he apologises on on reply then talks down to someone who is trying to explain where he is going wrong.

Some of us on this site are not up to his status with knowledge, we can still help by thinking out of the box.

The beauty of this site is you get answers from people who are trying to help, With answers from different angles.

Then its up to the person who asked the question, To work out which answer best suits the problem.

It may be he is expecting a perfect answer,

But if it were me i would be grateful for all answers, i would be able to decide which suits my problem best, Knowing that if the first answer doesn`t work, There would be other approaches

what type of battery?

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

http://www.google.co.uk/search?hl=en&rls=com.microsoft:en-gb:IE-SearchBox&q=lifepo4+electric+vehicle&revid=646838898&ei=jd6VS7yvAoT40wTi-fjtCw&sa=X&oi=revisions_inline&resnum=0&ct=broad-revision&cd=7&ved=0CEQQ1QIoBg

If the "kill a watt" clone shows that you are drawing one amp from the grid then what is the 2 amp rating? Is it the rated draw from the grid when the charger is pushing its maximum amount of current back into the battery? I would expect that your battery is not a 120 volt batter, therefore the voltage would be reduced and the actual amperage being pushed back into the battery is greater than 1 amp. Assuming no losses and 120 volt house supply, and a charging voltage of 48 volts, the actual amperage to the battery would be 1 amp times (120/48) = 2.5 amps. I hope that your charger is intelligent enough to know when to stop charging. Some modern chargers will charge at a safe level and as the battery voltage approaches it's maximum, they will taper the charge to a save trickle level.

Thanks for replying, the 2 amp rating is what is printed on the sticker thats peeling off the back of the charger. It's the charger that came with the battery from China.

There are higher amperage chargers, like 5 amp that are available, but it is believed that this higher charging rate will reduce potential charge cycles whith which my goal is to maximise.

I am assuming a minimum 2000 charge cycles with this battery and the math says, Sealed Lead Acid (SLA) @ $90 (36V12 amp hr)/300 charges= $.30 per charge (storage, electricity cost must be added as well); Lithium Iron Phosphate (LiFePo4) @ $500 (normally $800 for 48V/20 amp hr)/2000+ charges= $.25 per charge (storage).

Cost per mile is significantly less for LiFePo4, SLA; 150 days(battery must be charged immediatly after each use) @ 12mi a day = 1800mi/$90= $.05/mi. LiFePo4 2000+ days @ 12mi a day = 24000mi/$500 = $.02/mi.

The charger is automatic. When the light turns green I disconnect it.

Maybe it is best for everyone concerned here for you "Sir Richard-the-Blowharded" to ditch the battery on your tricycle and pedal the entire distance both ways as an overall weight savings and a way to get more exercise, since you've demonstrated all quite well how to huff & puff & blow smoke up everyone's arse? *LOL* Ohhhhh, the indignity of it all.....

CaptMoosie sitting on the sidelines enjoying the bashing contest for once....

Have a great sunny day!

I grew up being told there was no such thing as a "bad" question.

It's not the question. It's the arrogance of your response. Though you've exhibited some basic arithmetical skill keep in mind you are amongst professionals.... Lynlynch being foremost among them.

From your question

should i charge after 17 miles.

As LiFePo4 doesnt have any memory, Then i wont matter when you charge it, Will it?

Try these links:

http://www.pingbattery.com/servlet/the-LiFePO4-Chargers/Categories

http://www.e-bikekit.com/e-bike-batteries.html

Manual for battery in question.

http://www.juicedriders.com/storage/product-manuals/LiFePO4_48V15Ah_Charger_Manual20048003CHA001.pdf

basic quot from above.

Charging can be started at any discharge condition. This will not reduce the life span of the pack. It is not necessary to fully discharge the battery after initial use.

the charging process may be interrupted at any stage

I hope this helps.

Ps got info from google search