# Trojan Batteries and EV Motorcycles



## kek_63 (Apr 20, 2008)

6 x 12v Trojans will weigh around 300lbs, maybe closer to 400 - gotta keep that in mind when comparing range with the little batts.


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## frodus (Apr 12, 2008)

It's going to be very difficult to get 50 miles range with Lead acid. Also, Trojans are flooded lead acid, which isn't good for a motorcycle that leans. You need Sealed Lead Acid, but even then, your range isn't going to be that great.

What motorcycle frame are you going to use?

The hills are gonna kill ya


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## jrod84 (Jan 20, 2011)

Thanks for the info on flooded versus sealed. Thats one of those answers you never see until you ask the question.

As far as frame, I am hopefully going to go with a CB750 frame or the like. Something long and low. I kinda envisioned a retro cafe type build. My Honda Sabre 1100 is a hefty 640 pounds right now, so I am not so much worried about the weight issues I need to solve. I have also not given up on the idea of a sport bike frame, just have to be careful which one because I am 6'4".

The only saving grace about hills is that they give you opportunities to coast. I can coast some serious distance right now with my honda. I had two stretches where I coasted for 7/10 of a mile each time. 

The shear expensiveness of lithiums worries me that I would do something to harm the batteries.


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## frodus (Apr 12, 2008)

Then don't harm them 

The range is the issue with SLA. It'll be hard (not impossible) to get that range, and you'll need quite a large moto for something like that, and it won't be lightweight.

Just some observations I've seen on people's bike. Hell, even with lithium, it's gonna be hard for me. Not weight, but volume.


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## Sunking (Aug 10, 2009)

Using any lead acid battery is somewhat pointless. 

To start is energy density. At best you are going have 50 wh/kg with 40 wh/kg more realistic. Throw in greedy Mr Peukert Law and you are down to 30 wh/kg or less.

Second is with lead acid batteries you do not want to ever go below 50% DOD. If you want them to last no more than 20% DOD.

This is why all manufactures and hobbyist prefer lithium chemistry. Energy density up to 200 wh/kg and more, and you can discharge to 80% DOD without loss of cycle life. Pluss the Peuket Law penalty is not as steep with Lithium chemistry. You can get that 60 mile range with 1/5th the battery weight over lead acid technology.


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## jrod84 (Jan 20, 2011)

With lithium prices still over $500 per kWh. I need an 8 kW pack. I am looking at $4k in batteries alone on the low side. I may still decide to take the plunge but at those prices, I need to be sure the range is there and I can use as a commuter to make it cost beneficial. 

My next house will be closer to work but that is in my 6 to 8 year plan so my commute is what it is barring something happening with job.

I started looking at reverse trikes and different ideas to either be able to store more batteries or become more aerodynamic. Reverse trike is an interesting idea but I haven't seen it proven with an electric motor yet.

As a last resort and just to get a project going, I may go after 100mpg+ mark on a motorcycle. I have until January until the money starts changing hands.


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