Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is one!)

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Astrogroover
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Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is one!)

I've gained much joy (and about 2000 kms) out of my electric bicycle. I've also spent a small fortune on it, and experienced a huge amount of frustration because it's so hard to find reliable suppliers.
I am now awaiting the return of my 3rd LiFePO4 battery... It's being serviced under warranty somewhere in Taiwan, and I'm now told it won't get back to me for another month.
I'm not confident that it'll be any better than it was, if and when it gets here...
I have a 500W brushless motor kit installed on a Mongoose Hybrid commuter bike which, when it goes, is fantastic (though a little heavy).
I want to buy a decent back-up battery, and am nervous of getting another el-cheapo rip-off from eBay that will crap itself the moment it gets out of warranty, as has already happened to me twice.
Can someone PLEASE recommend a reputable OEM (original equipment manufacturer)that isn't attempting to make a 500% margin..., or should I build my own battery pack using DeWalt batteries? If so, is there a good BMS for protecting them?/A way the pack should be configured? Also, and finally, does the DEWALT NANO BATTERY 18Volt LITHIUM ION DC9180-XE contain LiFePO4 at all???
I suspect I may have to remain frustrated for some time, or fix this sordid business for myself??!

juanito
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Re: Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is ...

I haven't tried them, but Tenergy is a reputable battery manufacturer and they make both individual cells as well as battery packs. Tenergy LiFePO4 batteries At this same all-battery.com site I also saw some BMS's. But like I said. I haven't tried them and don't know how they'll do.

julesa
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Re: Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is ...

Yes, any of the DeWalt packs that use "nano" in the name contain A123 LiFePO4 cells. But if you're considering building your own pack, these cells will be less expensive and easier to assemble into a pack:
http://visforvoltage.org/forum/6285-new-headway-group-purchase

You can buy one of the BMS that's available through the group purchase, or you can build one of these BMS kits:
http://www.tppacks.com/products.asp?cat=26

Building an ebike-sized pack can be dangerous though. If you decide to take this on, make sure the cells are all equally charged before you connect them, be VERY careful about short circuits, take off any jewelry, and test everything thoroughly before making connections. You'll need to be very familiar with using a multimeter. You'll probably also need a way to charge individual cells.

If you're at ALL uncomfortable with this, I'd recommend you go buy a Ping pack, or a pre-assembled Headway pack (not available through the group buy, but you can order one direct from Victoria at chcj55 [at] gmail.com). Either of those should be more reliable than the average 200 cell 18650 ebay pack.

Astrogroover
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Re: Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is ...

Thanks for the advice. I'm curious to know who makes the 38120S batteries as I cannot find the manufacturer. What warranty do they offer?
I'll be needing a 24V BMS, and would probably like to go with a 20Ah pack, thereby requiring 16 cells. Do the actually make a 24V (25.6V) BMS for 2 parallel sets of 8 in series?
I'm looking at numerous alternatives, but this group buy looks promising...

eBike newbie, but eager for answers!

runfeng
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Joined: Sunday, March 15, 2009 - 02:08
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Re: Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is ...

Hello Astrogroover,
This is Steven, from Shandong RealForce Enterpriese,
we can produce 24V 20Ah LiFePO4 battery you need, with BMS, charger,
are you still need them ? please feel free to contact me.
Best Regards
Steven
sales_ae [at] realforce.com.cn
www.realforce.com.cn

dogman
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Re: Best LiFePO4 - DIY Dewalt or Reputable OEM (if there is ...

Any of those previous batteries from pingbattery? a 500 watt bike shouldn't need an a123 or headway pack in 20 ah size. If your previous batteries were round cell packs from cheaper vendors, they are more prone to have problems than the pouch type cells that ping uses. 3300 trouble free miles on my ping so far.

Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global

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