tweaking the Giant

I am the happy owner of a Giant Lite. I got it on eBay and I think it's new (or pretty much new).

I'm already dreaming of upgrades. Any ideas or suggestions? I have the 4 gear Shimano hub. I'm wondering about what the NuVinci hub would be like.

What about upgrading the battery? How many Amp Hours can I cram into the standard battery case? I'm not that handy, so any ready-made solutions would be warmly accepted.

thanks,

keith.

Hello, Keith.

You're the first Giant ebike rider here... I think. Not knowing much about them, can you post some specs and pics, especially of the controller, motor, batteries and battery box?

Upgrading/adding to the batteries is usually the easiest (but not usually the cheapest!), most bang-for-the-time-spent mod you can do for any EV.

The bike had a number of brand names over its 7 year lifespan. It was called the Lafree, the Giant, the Lite and the Twist (in various combinations).

The most detailed technical discussion can be found here. Another good description of the US version is here.

My version (called the Giant Lite in the US) has a 6.5 Ah NIMH battery running a 240-380W motor. The rear hub is the Shimano Nexus 4 gear hub. I don't have many details on the controller.

I've seen some discussions where people have recelled the battery case to increase the NIMH battery to 10Ah or so.

thanks for your help,

keith.

Krow said:

The bike had a number of brand names over its 7 year lifespan. It was called the Lafree, the Giant, the Lite and the Twist (in various combinations).

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Ya gotta wonder about a company that gives its bikes such crappy names... (do they really want to sell these)?

I think your 6.5ah cells are panasonic D nimh cells which have much lower resistance than other nimh D cells. so a disadvantage of using other higher capacity D cells are higher voltage sag and more heat.

if you are looking for a throttle on demand modification and more power/speed, see if a crystalyte or other brushless controller will connect to the motor. I see that the motor has Hall sensors so check if it is a 3 phase motor. Then you can see if the motor heats up at 36v or 48v.

So you gotcha one of those Panasonic drive bikes? Cool, I've got one too only the bike is a Japanese domestic brand called National. I've looked and asked for over a year about schematic or possible mods to the motor/controller with little to show for it.

Geared for 12MPH top speed the little 2.5 AH battery in my Panasonic lasts about 10 miles in level Manhattan. But, I opened the battery case and added a parallel plug to the battery cellls so now I can add extra 24V pack or two when I need more range.

Yours may be a 36V system but other than that it's probably pretty close to mine. The 24V system shuts down at about 31V and I've been unable to mod anything to allow me to run higher voltage.

I spoke to a dealer who once carried Giants with the Panasonic drive and he said the reason they're so reliable is that nobody seems to know how to mod anything. The brushless motor and software that controls it are very sophisticated and I bet most technical info, if found, will be in Japanese.

I'm currently drawing plans to re-cell the stock battery pack with 24V lithium chemsitry for when the stock NiMh dies and I've got a 16T rear cog to replace the stock 20T or so. Because the motor senses and drives the crankwheel my hope is that a final gearing change will be all that's needed to increase the bike's topend beyond the Japanese domestic limit.

Warmer weather will get me back to work on this platform and reveal a few more test results. Let's stay in touch should we learn anything more about the Panasonic drive and share the details?

IMO - Put extra batteries on there for now - that motor/controller is an AH miser! Compared to my hub motor bike in CA, the Panasonic has twice the range but it's not quite as much fun to ride as a twist throttle hub motor bike.

I'd also leave the 4 spd Nexus hub alone unless you're dealing with very hilly terrain? Electric bikes don't seem to need a lot of gearing since the motor auguments pedal power and it would cost a lot $$$ to go with 7-8 spd cassette or internal on the rear wheel.

But, easy enough to drop the rear cog down a few teeth and with the motor drive helping like it's programmed to do, 'should be able to get some higher top speed results?

Found this info on the http://www.pedelecs.co.uk/forum site.
Go here:
http://grandads.googlepages.com/

Has anyone got info on the controller as I have a Aprilia City Enjoy which uses the same peddle and torque senser setup as this. My Aprillia has burned out and I cant find a replacement controller and Im thinking this would do.

tesco said:

Has anyone got info on the controller as I have a Aprilia City Enjoy which uses the same peddle and torque senser setup as this. My Aprillia has burned out and I cant find a replacement controller and Im thinking this would do.

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I apologize if this hi-jacks the thread but tesco check here:

http://www.panabyc.co.jp/en/product_eb.htm

There's a Japanese site link and I know they made a lot of those drives. I think if you know somebody fluent in Japanese you could probably find a way to order parts and/or technical literature? If your Aprilla uses a Panasonic drive unit it may help?

Thunderstruck does a bit with BLDC controllers but I don't think the Panasonic hall sensors are like anything I've seen before so doubt they could help.

good luck and let's stay in touch as this stuff seems hard to source outside Japan but inside may be another story?