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motorcycle project battery question

1726 Views 7 Replies 3 Participants Last post by  frodus
i know some where in the depths of previous post this question has been addressed, however: i'm building a motorcycle EV, which would give be greater range 4 six volts or 4 12 volts ? my motor is a 24 volt off a baker electric pallet jack,
NOTE: while you ponder that i have my eye on some lithium ion battery they are currently in tow 48 volt battery packs but each cell is as follows:Saft, type- VL45E AH- 42 volt- 3.6
if i can get my hands on these for my project would they be greatly better then floodies ?
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all depends on Ah capacity of the 6 and 12V batteries and how much current they can source.

what Ah do you have at 6V and what Ah do you have at 12V?
the 12's are 245 ah the 6'ers are 110 ah
energy = aH capacity x voltage

obviosly the 12V 245Ah cells are going to give more range.

245 x 12V = 2940Wh, total of 11760Wh for 48V.
110 x 6V = 660Wh, total of 5280Wh for 48V.

But I would ABSOLUTELY avoid flooded lead acid in a motorcycle. i.e. DON'T USE THEM. Every time you tilt the bike, or put it on a kickstand its going to want to leak. Use a sealed lead acid battery or skip and go lithium.

Also, Do you realize that a 245Ah 12V battery is over 150lbs each? So 4 of them would be somewhere around 600lbs just in batteries.

Time to rethink some things.
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The weight of lead-acid would make any motorcycle unwieldy unless the pack was only big enough to go 5 miles at 30mph or something but there really isn't much point to that IMHO, not much fun. I'd go with lithium, something like Headway would do well and the price would be reasonable.

It all depends on the goals of your conversion for range and at what speed and conditions you expect to have that range.

Well, to some of what you say, I disagree. Lead is just fine for a conversion of a motorcycle. The first itteration of my motorcycle was using 12 Power Patrol SLA1116 18Ah 12V batteries I got free. They got me ~15 miles. It was a great way to launch the project for a fairly cheap price. Yes, he could go lithium directly, but if he can source cheap lead, there's nothing wrong with it. Most people that do motorcycle conversions have used Lead for their first bike and then work out all the kinks and move to lithium. I know lots of people use larger SLA batteries and get 30 or so miles out of them.

Now, as far as range and weight, I agree....The Lead pack was roughly 170lbs in my first version (480lbs for the whole bike, near stock weight). The lithium in my new version should weigh about 105lbs for 160 cells of the headway 38120S batteries (~70lbs lighter than stock weight).

I'm still in the tail end of my "upgrade" froml lead/brushed motor to lithium/AC Induction, but I know that I can fit more than double the capacity in the same space, and less weight.
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Thanks for the insight, I stand corrected. 170 lbs isn't as much weight as I thought 144v 18Ah would be.
Nah, those 18Ah batteries are only like 13.5lbs.

And just a sidenote, I wired 2 18Ah's in parallel, then series for 72V. Worked pretty well, and made putting 2.5kwh into a bike easier than putting 6 12V 36Ah batteries in there.
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