My new LiFePO4 battery and charger

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briotone
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Hi people,

I am a newbie to the Forum and also a bit of a dummy regarding electrification of bikes?

Give me an old V8 Chevy small block and I´ll strip and rebuild, no problem. To each his own!!

Long story short, I bought a Giant Cruiser beach bike, fitted with a Crystalyte Phoenix 5303 Racer rear hub motor (48 volt, 40 amp.= 1920 watts) and an absolute rubbish Chinese LiFePO4 battery, the size of a truck SLA, that collapsed after two weeks!

I then went the route of 4x12 volt SLA´s, that gave good service for a couple of years but were so heavy (each weighed some 10lbs.) that I decided to go to a LiFePO4 again, because modern technology appears to have moved on.

I was advised, because I only do a few miles a day, at low speeds (plus my wife has a Dahon ROO EL folder, that struggles a bit but she is happy)to buy a 48 volt x 12 amp. LiFePO4 battery, together with a 3 amp. charger.

This I did. It arrived yesterday, WOW!! Weight only some 10lbs. in a little rear rack bag. I then noticed the charger stated 5 amp.

So guys, I have three questions, if I may?

Will the battery handle my Phoenix Racer motor OK?

Should I buy and try to learn the intricacies of a stand alone Cycle Analyser?

Will a 5 amp. charger reduce my battery life by much?

Thank you in advance for any help and advice.

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reikiman
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Re: My new LiFePO4 battery and charger

Who is the maker of the battery pack?

What was the specs they gave for the battery pack, especially the rated discharge capacity?

The deal is - your crystalyte motor is powerful for a bicycle (48v 40amps = 1920 watts, or almost 3x the legal rating of an electric bicycle in the U.S.). The key number is the 40A discharge rate. Assuming you got a 10AH battery pack, that means your peak discharge rate is 4C, and depending on the cell maker a 4C discharge rate may be too much.

The battery pack should have come with a specifications sheet listing max discharge rates as a peak discharge you can do for a few seconds, or a continuous discharge you can maintain over time. What were those numbers?

The spec sheet should have also listed the max charge rate. And if you bought the charger from the battery vendor, presumably they mean for the two to go together.

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

briotone
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Re: My new LiFePO4 battery and charger

Hi Reikiman,

thanks for your reply.

I am sorry, I forgot to mention, the battery is 48 volt, 12 amp. LiFePO4.

I did not receive any spec. sheet from my supplier. They are the official Crystalyte end user suppliers for Spain, where I live. That was something else I forgot to mention, apologies!

They manufacture the battery packs themselves, because they want to be sure the quality is consistent, something that had been lacking in the past!!

I did make sure he knew the specs. of my system. I also explained that my wife has a Dahon ROO EL, which is rather slow, so I do not reach any great speed anyway and the area we live is very flat, with only slight inclines, which is why he recommended this particular battery.

There is a language problem here for me but my wife speaks fluent Spanish, so I can get her to talk to the supplier. He does speak some English but with the aid of a Google translator, so it is all a bit long-winded.

Does the fact the battery is 12 amp. help my cause, may I ask?

I ordered a 3 amp. charger but although the invoice stated they would supply a 3-5 amp., the label only states 5 amp?

reikiman
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Re: My new LiFePO4 battery and charger

12A helps a little .. still depends on the ratings of the cells.

As for the Cycle Analyst question -- they are EXCELLENT. I have Cycle Analysts on all my electric vehicles, from bicycles up to my electric car.

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

jdh2550_1
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Re: My new LiFePO4 battery and charger

I agree with everything reikiman says - I just wanted to add that I'm 90% confident you'll be fine and wanted to address the charging side a little more.

1. Will the battery handle my Phoenix Racer motor OK?

2. Should I buy and try to learn the intricacies of a stand alone Cycle Analyser?

3. Will a 5 amp. charger reduce my battery life by much?

1. I expect the pack will be fine - given your stated "low stress" riding. If you can take a picture of any markings on it we can probably help identify it. Amp draw will peak during acceleration (especially from stop on an uphill). The advantage of an e-bike is that it has pedals :-) You don't need to pedal it up hill but even just an initial push on the pedals should help reduce the peak load. Oh, and no burnouts!

2. YES. I've actually never owned one of these but from what I know they are one of the best aftermarket devices. More data is always a good thing. :-)

3. I very much doubt the peak current of the charger (5A) will cause you any grief. The question is more to do with "how smart" the charging system is. And how smart it needs to be is dependent on the pack construction (number of individual cells) and pack usage (how low do you drain it? how often do you charge it?). On the usage front: seeing as you only go a few miles every day and you have a fairly big pack you're not draining it very deep and if you get in the habit of charging it after every use you should keep the pack happy. One caveat being if you're going to store the bike for a long time you want to store it with the pack about 60% full. On the "smart" front: do you have a BMS? I don't know if David runs a BMS on his e-bike? It's essential on large packs that get worked hard (for example in a maxi-scooter)

Enjoy your ride and raise a glass of Sangria for us... (but not while actually riding ;-))

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

briotone
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Re: My new LiFePO4 battery and charger

jdh2550_1,
thank you for your response, I appreciate the input.

I have emailed my supplier for the statistics mentioned by Reikeman and await his response.

As an aside my supplier has apologised for sending a 5 amp. charger by mistake. He is sending a replacement 3 amp. model. He says the 5 amp. one is 25 Euros more anyway!!

I do believe the charger has a BMS because the rather sparse manual does list a series of conditions in which the charger will indicate something is being done or not, as the case may be and automatically preserve the batteries condition, i.e., reverse polarity connections, etc., and several other functions it takes care of.

The worries I have with the Cycle Analyser are, I need the Stand alone version that requires a shunt between the battery and the controller(because I do not have the 6 pin connector) which will create an even larger bundle of cabling in the controller area on the bike, to try and hide somehow.

The only other thing is trying to benefit my rather "lack luster" mind with an understanding of the more important features and functions of the unit. However, I shall probably buy one and struggle through somehow?

I need to buy from the Netherlands. They have offered to attach matching Anderson 50 amp. connectors to the pigtail leads for free, but the shipping is very expensive I notice.

briotone
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Re: My new LiFePO4 battery and charger

Reikiman,
I have had a reply from my supplier, together with a complete technical manual re. the battery. Rather than try ans send that, I have translated his email to English (sort of) in the hope that you could maybe be kind enough to peruse it?

Here it is:

Dear Antony,

Sorry to write you in Spanish, but I changed my email and the translator does not work. I'm also very busy and do not respond as fast as I would.

I send you attached the technical characteristics of LiFePO4 cells.

As you can see from the attached specifications, to support load testing up to 0.5 C is if your battery is 12Ah could load up to 6A (12A * 0.5 C) without that it would prejudice the life cycles. As you have a charged battery 5A entonce your not in danger of shortening life. Anyway, I can also change your charger charger 5A for another 3 A.

The download supports hata 5C, that is 60A (12A * 5C), but I think BMS can put up so it is a download of 15-35A BMS so if you get over power, the battery is temporarily disconnected to protect you . Anyway do not worry you have a good battery and have made a good buy, I sincerely hope you enjoy it.

If the above doesn´t make sense, I can transfer the Manual, but it´s a bit on the lenghthy side??

Kind regards and thank you for your help, in advance.

P.S. I have also ordered a Stand alone Cycle Analyser.

briotone
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Re: My new LiFePO4 battery and charger

jdh2550_1,
If you would be kind enough to look at Reikiman´s latest post from me, you can read what my supplier has stated!
I have tried to post the Manual but for some reason it will not let me "paste" it anywhere, it is grayed out??

briotone

PS I am laying off the Sangria, in favor of Coke Zero, lovely!! Saludos!!

Tonyxhb
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Re: My new LiFePO4 battery and charger

are you finished this? I thought the battery is ok. Please let me know your process on this battery,I would like to know this also

briotone
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Re: My new LiFePO4 battery and charger

I am waiting for any response to my last postings, but remember, these people have other things they must do, so it may take a while for a response, if at all?

I have learned in the meantime that my battery is quite strong and allegedly can take a 5 amp. charge without creating a short life.

I have oredered a Cycle Analyser, to help me keep an eye on discharge, etc.

My battery can handle my motor, if I exercise reasonable restraint!

I am only really waiting for a "blessing" from the Gurus on this great Forum!!

reikiman
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Re: My new LiFePO4 battery and charger

I'm sorry to have taken so long to respond.. in any case the specs on the battery pack are approx what I thought they'd be. If I understand it right, the max discharge would be 35A which would be not quite enough to satisfy the max demand from your controller. But my experience with this sort of battery is if the BMS turns the system off, you simply unplug the battery then plug it back in. On my bicycle the connector for this is near the seat tube, and I've been able to unplug then plug it back in while riding. And over time you'll learn to not hit full throttle .. ;-)

__________________

- David Herron, Green Transportation Examiner, Green Transportation Info, The Long Tail Pipe, Electric Race News, davidherron.com, 7gen.com, What is Reiki
- Charger bike (rebuilt), Electrified Electra Townie, 1971 Karmann Ghia

briotone
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Re: My new LiFePO4 battery and charger

Please do not apologise Reikiman,

I realise you must be busy with many things in your working day!

I have an on/off key operated switch on the positive side oof the battery feed, so if I experience trouble, I guess I can switch that on and off. It is located within easy reach for me.

Thanks for your input.

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