morph999 

I took my 3rd or 4th run on my new lifepo4 batteries. These things are awesome. I've doing runs on 1/4th of the battery that my entire SLA batteries could not do.

I'm getting 3.5 AH per 6 miles on my 5303 hub motor. If I lose weight, maybe I can increase the efficiency. That means I can go about 18 miles on 10 AH. That'll be plenty for me I think. That's a good ride. I was shooting for 15 miles range. By the way, that's without pedaling and going between 15 - 20 mph.

BroadwayJoe

SLA, eh? Even high-current NiMh is a very dramatic improvement - isn't it nice NOT to deal with the extreme weight, gradually sagging voltage and oversold AH capacity of lead chemistry batteries? Only downside seems to be the cost but even that works out over time if you take care of 'em.

In my experience, no peddling, 1AH per mile is about average for my 48V 20-30 amp BLDC hub setup. Hard acceleration eats into range and of course hills and headwinds can create large differences over the same route but it seems like you're getting excellent range.

I'm happy with a 1AH per mile - easy to calculate that way. Need 15 miles - remember it's not an exact science. Widely variable resistance experienced during each ride complicates estimating so get 20Ah battery and go easy into winds and from stops until you can see the charging destination!

Oh, and if into really understanding a nice battery pack and how it performs - one of these kicks major booty:

https://www.hobbycity.com/hobbycity/s...dProduct=10080

nwmtbiker (sp?) posted a link before and I bit on one. Best thing I ever did for best understanding battery performance. For folks like us it's extremely useful to know how much electricity you take out and put back in...

edit: I see your other thread - nicely done. haven't been around much. too busy building and riding!

johnclaim

Thanks for post.

By
John Claim
Bestofcolleges in US

wernmax

I too have the 5303 hub motor, and an amazing 48V10amp set of DeWalt A123 batteries that was pushing 500lbs of me and a prototype trike up and down some serious grades for awhile.

That pack was set away in the shed with a resting voltage of 53.4volts a year ago, and when I just checked, was still at 53.4 volts. They have sat through two winters and a summer without a charge! That alone would have killed even a brand new set of SLA batteries. Now I'm buying a 40 amp LiFepo4 48V pack for a new trike project that I want to run two motors on.

Zephyr Boy

I like my "ping LiFePO4 48v15ah V2.5" (standard size from his website-300x105x150mm) it arrived in a week after ordering it directly from his website. First impressions – it was light, durable battery pack it had 4 wires protruding from it (one big red wire, one little red wire, one big black wire, one little blue wire). No instructions inside the delivery box, you can download the pdf file at ping's website - "Wiring Guide for V2.5 Products.” The size of the battery pack fits perfectly in my Topeak MTX Trunk Bag DXP.

SLA batteries are in the Stone Ages: high maintenance, must plug in immediately or suffer sulfation (battery damage); heavy; low mileage, that every decreasing power curve until you just get only 4 miles per charge.

When I replaced my SLA batteries, it was like installing a new high performance engine. I upgraded from a 36v to a 48v, there is certainly a "kick" to my bike now, and the top speed feels faster (25-30MPH), and the mileage is FAR superior to SLA . Before, using my SLA 36v 18AH, I was getting about 15 miles per charge declining to about 5 miles per charge after 6 months of using. My ping battery I can easily do 15 miles (my normal fun route) plus 5-10 more miles to test the range: bottom line, I feel I can go ~ 30miles on a single charge.

Because the LiFePO4 battery pack is so light, it took about 13lbs off my bike's weight: that’s like not carrying a bowling ball around with you on each bike ride. So, if the battery pack died or you just want to ride un-assisted, the bike's drop in weight was very noticeable. With my LiFePO4 battery, my bike's weight feels like a regular bicycle again.

After owning my LiFePO4 battery pack for 6 months, I notice I have more peace of mind while riding. I know that I have the range to go anywhere (i.e. work route, fun route, chore route all combined), I can leave it un-charge at a friend’s house or at work, and know that the battery is not being damaged while sitting there. The long lifecycle means I can own one LiFePO4 battery pack for 3 years (instead of a pack every 6 months using SLA). The worry about having enough juice to get back home (SLA who knows if you just lost a couple miles permanently the night before) is gone from the back of my mind. In conclusion, my LiFePO4 battery pack is small, has at least double the range, light weight, safe, powerful, long life, gives me peace of mind: LiFePO4 is simply awesome!

chvid

I totally agree with Zeph. I've got two PING 48V 15Ahr - one V2 and one V2.5 . They are both awesome. With two of them on my big recumbent, in parallel I'm good for around 80 miles with moderate pedalling. The BMS in the batteries have an LVC of 41, but I rarely go anywhere near that level. Under load the voltage sag is up to 2 volts depending on the amperage. They typically run around 49-53 volt range, after the "surface charge" is burned off after charging (down from around 60 volts). The LEDS on the v2.5 BMS are interesting to watch, as balancing occurs. I know Morph is not a BMS fan, but for me they confer enough peace of mind that they are worth having.
I live in Canada, and incurred no extra charges, other than the stated shipping charge - around 600 Cdn. landed at my door.

morph999 

Good stories. My lifepo4 is still about 20 lbs My SLA's were about 30 lbs so I lost 10lbs.