Battery advice needed -

[mthead]

I have a 26" Schwinn Beach Cruiser with a 750 watt Aotema front wheel hub motor. I'm an old dude, in no hurry and weigh 240 lbs. I'd like to peddle as little as possible and hope to have at least a 10 mile range. Where I live is flat as a pancake so hills aren't a problem. Finances ARE a problem. I'll be buying a 36 volt battery and my choices with Ping Batteries are 10, 15 or 20 Amps. My questions are - will the 10 Amp serve my needs or do I need more Amps? And, should I be looking at other battery options, than Ping?
Thanks for any advice.

 

[dnmun]

sun-thing28 and hunk 801 on ebay are the cheapest sources of the lifepo4 pouch packs. they are cheaper because they are shipped surface freight and not air freight.

 

[mthead]

Thanks for the source info, dnmun. Much appreciated.

 

[d8veh]

IMHO LiFePO4 is too heavy for an electric bicycle. There's much better alternatives available now.

 

[dogman dan]

10 ah of 36v lifepo4 will work fine with that motor kit. But you'd get a better lifespan, resulting in a lower cost per mile on the long haul by getting a 15ah.

Among the cheap battery vendors in china, the one to avoid is V-power HK. Ping is great, Sunthing not bad.

 

[dnmun]

there was another guy who had ordered a new Vpower pack recently so it will interesting to see if his pack is like the other Vpower pack we saw that the other guy had opened. it seems like Vpower has been reading here and they now use the big 26650 cans now and they pay attention to the overlap of the paralleling strip so that it doesn't overlap the case on the anode ends.

so i have reduced my opposition to the Vpower pack if that is how they are built now. it would be nice if the guy who just ordered the new Vpower pack would open it up so we could see it.

but i still think the sunthing guy has essentially the same product as ping, except i think ping has more control over the manufacture of his pouches now too so that implies he can upgrade the quality of the chemicals and use better lifepo4 cathodic powder. but i have no way to know if the pouches that sunthing guy uses are less in quality or if all the pouches are now just generic and built to a specific level of grinding for the lifepo4 powder and additives to the electrolyte.

i don't know how we could ever know the inside stuff.

 

[mthead]

Hey, Dogman! I remember you from years ago. Good to see you're still here. I went ahead and ordered the Ping 36V 15amp and am pretty excited now. Way back about the time I bought the Schwinn and the motor kit, my wife became very ill and medical bills prevented a battery purchase until now. I just plowed through the posts in the FAQ section you recommended and now have a case of numb brain :?

 

[wesnewell]

Any battery purchase, regardless of chemistry, should have an amp output capable if meeting the max amp draw of the controller. The motor wattage size doesn't matter at all. For instance, if the controller has a 30A max, the battery pack you get should be rated for at least a 30A output. For weaker chemistries rated at 1C that may require a 30AH pack.

 

[Syonyk]

IMHO LiFePO4 is too heavy for an electric bicycle. There's much better alternatives available now.

Can you justify that with numbers?

For the OP, a 240lb rider and an ebike is going to be rolling 280-300 lbs over the road.

A Ping 15AH 36v pack and BMS weighs 12.3 lbs - http://www.pingbattery.com/36v-15ah-lithium-lifepo4-battery-pack/

It looks like the comparable energy in lipo pouches, the lightest thing I am aware of, would weigh 5-6 lbs - so half the weight.

A savings of 6 lbs on a 300lb rolling weight is 2%. Do you really think that's going to make a radical difference in how the bike rides or handles, and is it worth losing the safety and long cycle life of a slightly heavier pack?

 

[mthead]

My thought exactly, Syonyk. I'll keep the battery low in the frame but I just couldn't see how an extra 6 lbs would make a bit of difference.

 

[mthead]

@ wesnewell - My controller is 36V 20 amps.