Complex question comparing lipo to lifepo4

[ebikedelight]

For me this is a complex question, because I havent ever used lipo for my ebikes.

Using a yescomusa 1000 watt .D.D brushless rear hub motor and a Lyen programable 12 fet controller , will I get longer travel times with a

1. One - 48 volt lifepo4 - 16 cell ---- 20 a/h battery

or

2. Three ---- Multistar - 6s lipo - 16000 mah wired in series to get me a total of 18s - 16000 mah


The route being travelled is the same with both packs....flat land , cruising around 20-25 mph with weight of bike and rider being 270 lbs { not including individual battery weight of each specific option mentioned } .

 

[wesnewell]

1 is 1024 Wh and 2 is 1065.6 Wh, so in theory you would get more distance from number 2 assuming the AH ratings are accurate and you drove the same course at the same speed. Of course your top end speed would be more with the 66.6V rc lipo pack if you wanted more speed.

 

[dogman dan]

Much depends on the real world usable capacity. Bottom line though, if you ride the same speed, 100wh of one type is the same as 100 wh of the other, as far as range is concerned. Both can go a long way.

Depending on the vendor, type of cells, quality of construction of it, the lifepo4 battery could have as low as 15 real world ah right out of the box. That's not typical, but can be for some of the very cheapest lifepo4 packs out there. But more likely, the thing will deliver at least 19 ah for at least the first year. It has a bms and a relatively safe chemistry, so you plug it in, go to sleep, no worries. If you run out on the road, the bms will stop you from ruining cells.

With the RC packs, they will deliver the 16 ah, but many choose a charging strategy and more conservative stopping point to make using RC packs without a bms less of a hassle. So you might end up running with more like 13 ah usable. And, as always....

Never store or charge RC lithium cobalt in a place you wouldn't build a fire.

Counterpoint, The RC pack will be a LOT faster, 8) have a lot less voltage sag under load, 8) and be lighter and more compact than lifepo4. 8)

 

[ebikedelight]

Thanks for the info.

Ive never bought lipos form hobbyking....and was interested in purchasing 3 of these packs, to run i n series, but theres a couple of really bad reviews.

http://www.hobbyking.com/hobbyking/store/__72326__Multistar_High_Capacity_6S_16000mAh_Multi_Rotor_Lipo_Pack_US_Warehouse_.html

Im concerned that if I get 1 or more bad packs out of the three packs I purchase, hobbyking will be reluctant to replace the pack or give me full monetary refund.

Can anyone suggest a high Mah brand , that would get me at least 16 - amps or more , in 16s - 18s configuration that has a fair price and reliable quality ?

I think its time for me to try lipo for my ebike and let my wife continue to use lifepo4.

 

[wesnewell]

It's hard to beat the 4s hardcase packs for value at ~ 31 cents per wh.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html

 

[ebikedelight]

It's hard to beat the 4s hardcase packs for value at ~ 31 cents per wh.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html

That is a good deal.....and I would be happy with 16s..with 4 packs wired in series...but the 5000 Mahs is to low for my needs....Id have to buy 16 packs to get 20 a/hs in
16s format . .....

 

[cal3thousand]

Just make sure the Multistars' low C-rate (relative to other LiPo) is going to be enough for your needs. That should be under 50A for that 16Ah you are looking at.

 

[ebikedelight]

Just make sure the Multistars' low C-rate (relative to other LiPo) is going to be enough for your needs. That should be under 50A for that 16Ah you are looking at.

My ideal lipo setup would be 16 or 18s - with 20 a/h capacity. ...for around $400 or less...

Im still not sold on purchasing the multistar brand....I like that they are inexpensive, but dont like the hit and miss reviews.

Mu upgrade from 48 volt lifepo4 to higher voltage lipos , really isnt to get more top speed { im happy with 36 mph on my lifepo4 } but to have more torque/ power when needed.

 

[ebikedelight]

How many topics about sellecting a battery are you going to start?

According to your latest one you have all ready order a battery with out saying what was it.

as many as I need , to pizz off our local greek guy.

or

about as many as you post about your stupid 250 watt mid drive system.

the lifepo4 i ordered is for my wifes bike.

im considering going to lip for my bike, which currently uses 48 volt lifepo4.

did I answer your question ?

 

[wesnewell]

15 4s packs as 20s3p is 1110 Wh. More than the either of the other packs and will provide more speed if you need it. You'd probably want a 20s bms for this as using a balance charger with odd number of packs in series is a problem. All the options with rc lipo make it hard to decide, But that's one thing I like about using it. I can change it up to whatever I want in minutes.

 

[dogman dan]

How about 18s 15 ah. 9 of the 6s 5 ah packs. If you get a bum pack, easier (or at least cheaper) to replace a smaller pack.

Any more than that, you get into a big large pack that's getting harder to carry.

 

[ebikedelight]

How about 18s 15 ah. 9 of the 6s 5 ah packs. If you get a bum pack, easier (or at least cheaper) to replace a smaller pack.

Any more than that, you get into a big large pack that's getting harder to carry.

this pack ;

http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html


what would my watt hours be compared to the 48 volt - 20/ ah lifepo4 I have ?

 

[wesnewell]

To find watt hours, multiply AH size times nominal voltage. A 16s lifepo4 pack is 51.2V. An 18s rc lipo pack is 66.6V. Assuming both are 20ah packs, 20x51.2=1024wh, and 20x66.6=1332wh.

 

[ebikedelight]

To find watt hours, multiply AH size times nominal voltage. A 16s lifepo4 pack is 51.2V. An 18s rc lipo pack is 66.6V. Assuming both are 20ah packs, 20x51.2=1024wh, and 20x66.6=1332wh.

thanks...so my lifepo4 is giving me 1024 watt hours

and

the 18 s turnigy lipo - 15,000 a/hs would give me 999 watt hours

since the lipo is 5- 6 lbs lighter ands only 25 watt hours less...I doubt there would be any noticeable difference in pack longevity when commuting the same routes.

 

[999zip999]

It boils down to how you ride. With more available power more throttle less range. Unless we are talking about a robot riding an ebike. Throttle twitch. Lipo has more power so is easier to use more.
Like on salad dressing bottle one with a plastic top with a small hole that you need to shake to get out more or a 3/4 in. hole which bottle would last longer even if the bottle with the large hole has one more oz. of dressing, and cost less.