Electric Bikes - LifePo4 battery questions

Am planning on buying a 36V conversion kit (probably the Amped bike kit), and have been looking for a good price on LifePo4 batteries.
As I'll most likely end up getting one from China, I'd like to know what I should look for.

Probably will get a 36V 10Ah LifePo4 battery with BMS.

They have offered either a 2A, 3A or 4A charger. I'd like to get the cheapest one.

1. How long do each of the chargers take to charge this battery?
2. Is a slower (the 2A charger) better for the battery over it's life, or doesn't it make any difference?
3. Does the BMS take care of protecting the battery from overcharging, etc......or does the charger have to be a "smart" charger?
4. Is there anything specific I have to request besides "36V 10Ah LifePo4 battery with BMS"....ie:are these batteries all basically the same, & will they all work for this electric bike application?
5. I'll be putting it on the rear rack, so I'm not overly concerned with width of the pack (as I would if I were to mount it between my knees). That said, are all LifePos approx the same size?

thanks

If you're looking for a HIGH QUALITY 36V/10AH LiFePo4 battery pack, take a look at the new E-BikeKit battery pack here:

http://www.eco-wheelz.com/catalog/ebike-kit-lifepo4-battery-p-178.php

A pretty good price at $599 considering it's nicely packaged with an aluminum case, BMS, charger and Anderson connectors. You could use it with an Amped conversion kit, but if you buy it with the E-BikeKit (Nine Continents motor just like Amped), you can actually save $100. I'm trying not to sound like a "salesman" - but this is the nicest battery pack out there!

I would highly recommend you move up to at least a 12amp/hour or 15 would be ideal. When you start running 12 amps or lower on those amped bikes kits it's on the verge of not providing enough amperage the way the ECU is setup and can cause overheating up steep hills. The ECU struggles to utilize 10/12a/h battery's up steep hills and can cause it to cut off/overheat easily. Running a 15amp/hour would be the proper way to do it, and it can take you up steep hills with no throttle cut-off at all.

ecowheelz I'm sorry but that is a ridiculous price for a 36v 10a/h battery. You can get a 15a/h 36v battery from ping in the $420 range with charger and bms and yes, they are TRUE LifePO4 cells. An extra $180 bucks for 5 amps LESS and an aluminum case and anderson connectors which cost barely anything? Your choice billkelm.

ecowheelz I'm sorry but that is a ridiculous price for a 36v 10a/h battery. You can get a 15a/h 36v battery from ping in the $420 range with charger and bms and yes, they are TRUE LifePO4 cells. An extra $180 bucks for 5 amps LESS and an aluminum case and anderson connectors which cost barely anything? Your choice billkelm.

It's always cheaper to buy individual components and build a battery yourself. But some people don't have the patience or the electrical ability. This battery pack is perfect for those people since it's "ready-to-go" right out of the box. If the battery is ordered with the kit, it's $100 OFF ($499) which isn't a bad deal (compared to your $420 "quote") considering no work will be involved to set-up or wire the battery. Besides the Anderson connectors, BMS and charger, it also includes a very nice aluminum case with handle, on / off key swith and lockable rack mount. It's a high quality, complete battery package that looks excellent (unlike most "home-made" battery packs seen on many custom e-bikes). In my opinion, it's a great deal and one of the nicest batteries out there...

...appreciate the recommendations...but, can anyone answer my original questions?

thanks

2 AH charger.... takes 5 hours.... and so... 4 ah will take 2.5 and so forth... hope that helps. The job of the bms is to protect from overcharge/Discharge. Slower charging is better but not always possible or reasonable. Many of the battery systems are very different. If your running a 40A controller the battery mentioned above would suck. Pings would suck also. If your running a 20A controller than they and most will work. Anyways... this should give you a few answers to your original questions.

Sorry about missing your questions...

1.) kyakdiver is right... 4-6 hours with a 2AH charger, about half with 4AH, etc.
2.) A faster charge might be convenient, but a slower charge is more effecient and will help extend the life your batteries over time.
3.) Almost every charger produced today is a "smart charger", so even though the BMS provides protection, you'll most likely end up with a "second-line-of-defense" with the charger.
4.) As already mentioned, specific requirements will depend on the system and the controller.
5.) Not positive about sizes, but I'm pretty sure the cells are all close in size...

slow charging on these types of cells offers no benefit. The best charge is to go 1C but with huge packs like this, delivering 10-15 amps might mean a more expensive charger.

Lithium based cells are almost 100% efficient when charging.


as for size, the actual cells can vary in size depending on quality. Higher quality cells can fit more mAh's into a smaller space.

Thanks for all of the help......when you talk about 20A or 40A "controllers", are you are talking about the
"computer"/brains component that would come with the hub motor?
Not sure what comes with the Amped kit??

You might want to also check out HighTekBikes batteries: http://www.hightekbikes.com/battery.html

You also have to factor in if you're taking the charger with you.
I find the 2amp plastic charger , which uses a fan, better, because the components are well packed and will not break during commute.

I have a 48 volt, 12ah LifePo4 battery. My 3amp alluminum charger, which was considerably larger, only lasted 8 months. The coil within broke off from too much movement and because the coil was poorly secured. (I take the charger to work and home). At the office, one day, I was smelling fumes, was coming from the charger.. later when I called the dealer they asked me to bring the charger to the phone and shake it, it clanked, they were familiar with the symptoms and asked me if I travel with the charger.

The model : Kingpan 3A alluminum charger is not meant for lugging around. But if I could give a word of advice, it would be: inquire if the charger can be lugged around when you travel (if that's something you're planning on doing).

Thank you fot that information.
I have the EbikeKit, 500 amp 36v Lifepo4 Great setup. I have had it for a week an am really enjoying it. So much so that I need to order a second kit fot my wife.

Did I understand you to say that this motor is the same as the 9Continents¿