84v lead acid 20aH vs 72v lithium 20aH

[Svard75]

Hello,

New ebiker here. I'm 240lbs and commute 40kms both ways total. Will ride year round depending on the roads but we do have snow here and gets cold, often times -40 Celsius.
Would you recommend an 84v lead acid battery powered ebike or a 72v lithium battery powered? The dry weight of the ebike alone is about 50lbs lighter for the 72v.

Many Thanks,

 

[indianajo]

On the one hand, dragging around 50 extra pounds is a nuisance.
On the other hand, LiIon doesn't work below 0 deg F. Only lead acid does. 72 v puts undue stress on motors generally designed for 48 v.
I'd say in your circumstance, a gasoline motorcycle is in your future. Or a car. -40 C is a danger to hands & toes. I've been out in -25C and we had trouble keeping diesel trucks running.

 

[Svard75]

On the one hand, dragging around 50 extra pounds is a nuisance.
On the other hand, LiIon doesn't work below 0 deg F. Only lead acid does. 72 v puts undue stress on motors generally designed for 48 v.
I'd say in your circumstance, a gasoline motorcycle is in your future. Or a car. -40 C is a danger to hands & toes. I've been out in -25C and we had trouble keeping diesel trucks running.

Thanks for your reply. To clarify the -40 is in Celsius not Fahrenheit. I think comparable is -20.
I just read that lead acid perform much better in colder temps so I think I answered my own question.

 

[indianajo]

Yeah, the field exercise I was out on was -18F with a 30 mph wind. The warm spaghetti would freeze on your fork lifting it from the plate. The tent heaters fuel jellied up and quit working @ 3AM. The diesel fuel was jellying up in the fuel filters & wouldn't flow. I suppose the Soviets still have #1 diesel fuel; we didn't.
LiIon is down to ~half range just at 35 deg F. Battery cars have battery heaters, but a bicycle can't afford that weight or the insulation.

 

[Svard75]

Yeah, the field exercise I was out on was -18F with a 30 mph wind. The warm spaghetti would freeze on your fork lifting it from the plate. The tent heaters fuel jellied up and quit working @ 3AM. The diesel fuel was jellying up in the fuel filters & wouldn't flow. I suppose the Soviets still have #1 diesel fuel; we didn't.
LiIon is down to ~half range just at 35 deg F. Battery cars have battery heaters, but a bicycle can't afford that weight or the insulation.

What about adding a bit of antifreeze to the fuel?

Was your comment about battery cars have heaters directed at Tesla’s?

 

[harryS]

Interesting fact. -40C is the same as -40F. The coldest modern temperature in Toronto was -33C (-27F) at the airport.

Way too cold for exposed skin on a scooter.

 

[Svard75]

I just wanted to update this thread. I picked up the 84v eagle deluxe.
couple of things to note:
Plenty of power to get me up hills no problem. Cannot comment on the lithium version as they didn’t have it to test. I can only assume it would also have no issues given the 60lb weight difference.
so far so good.

 

[Svard75]

Went for a quick ride today. Temps are around 2 Celsius. I had the charger on the bike overnight on a timer set for 6 hours. The voltage initially displayed 94v. After a few minutes it dropped to 92v. Then drove around for about 15 minutes and the voltage got down to 84. How the hell can I expect to make even 17 kms if this is what I’m seeing. The app has 72v set as the lower limit.
is there an initial discharge then more gradual discharge that occurs with these bikes?