48V Conversion.......

[Spacelander 1946]

Has anyone completed a 48V conversion with a Lifepo4 battery on the GM 500W hub motor?..........This would involve a change of controller + battery pack, an expensive option. Does the performance/torque improve markedly considering the extra $$$. My kit is a bit dissapointing when faced with even moderate hills. Please advise....Cheers.

[biohazardman]

MY inexpensive GM 36v 500w motor will take me and the bike 260lbs up moderate hills at 10-14 miles an hour.  But if speed drops to less than that I need to pedal.   I am 56 years old overweight have several partial dissabilities and Hepititis-C still I can climb hills like the better part of the very healthy crowd, spandex type, ;^) for about a mile.  With my motor and some physical effort to date I have passed all of them I tried to pass. The cheap GM will do better at 48 volts with a top speed near 30mph but may overheat with high loads and long steep grades from what I have read.  The more expensive geared motors rule on hills because of thier torque but once again high loads, high voltages and long steep hills will overheat them.  If you want to climb mountains the C-lite 5000 series motors with lots of batteries seem to werq well and costs allot also. Check it out for yourself.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=5652&st=0&sk=t&sd=a&hilit=canada

[pdonahue]

Has anyone completed a 48V conversion with a Lifepo4 battery on the GM 500W hub motor?..........This would involve a change of controller + battery pack, an expensive option. Does the performance/torque improve markedly considering the extra $$$. My kit is a bit dissapointing when faced with even moderate hills. Please advise....Cheers.

I did a conversion on my previous bike from 36V to 48V, but it was with cheapy SLA batteries.  It would take me up all but one of the local hills, though to be fair, many cars have trouble with that one as well.  I actually climbed the local ski hill with pedaling just to see if I could. 

My bike had a fight with a car and lost, so when I was replacing it I just went for the 48V kit.  So far so good except for the frying the charger by plugging it in reverse polarity.

Pete

[Spacelander 1946]

Thanks for your comments....
Another problem I have is the BMS overheats then cuts out when in regen mode. I have heard that this happens with some LIFEPO4 bateries & the mosfets(what ever thay are?) Maybe I have a battery problem (I had to repair poor conections on my battery purchased though E-Bay from China) I hate the regen mode anyway. Ohh well, more money to spend I guess. Cheers & Good Luck!

[Lanchon]

this could happen if cells have high internal resistance. its VERY dangerous for the controller to be disconnected from the batt while regening. it's gonna fry if you keep it up; don't.

[biohazardman]

Has anyone completed a 48V conversion with a Lifepo4 battery on the GM 500W hub motor?..........This would involve a change of controller + battery pack, an expensive option. Does the performance/torque improve markedly considering the extra $$$. My kit is a bit dissapointing when faced with even moderate hills. Please advise....Cheers.

Well my original regen died so did the 48v conversion as I had the controller already and it fit in the box.  I have 36v of Lifepo4 and 12 of the SLA flavor.  Just finished it up and the wheel spins up although I worry about the throttle.  Will find out more on the way to werq tomorrow. OK I lied again just got back from a run down the road only hit 23mph with low tires and not fully charged battery.  Blew another fuse on the way into the house and found the on/off switch to be toasted.  Likely I was not running at full voltage.  Still it has alot more torque early on and more later.  Put a grin on my face and I'm hooked on the 48 for now 60v is right around the corner? ;^)

[Nicobie]

I just finished my 48v conversion yesterday and I'm getting about the same results, 23.4 mph with more torque. My range is down about 15% but that might be because I was a bit 'throttle happy'. I'm using 4 x 10Ah SLA batteries and am able to pull 4.7Ah out of them before the motor cuts out bad. My Watts Up meter shows a high of 38A (momentary) used and at full throttle it shows around 31A. I run a 30A fuse and it hasn't blown yet. Even though I didn't check real close, I didn't find anything getting warm. I need to check what voltage it runs at with a full 53.4v charge. I might have a wiring problem as I think it showed only 46v crusing on a full charge. Even though the batteries are only 10Ah I don't think they are the problem as they only have about a dozen charges on them. But they might be as I really don't think SLA's are good for 3c (or even 2c). Can't wait until I can afford 20Ah of LiPo4's.

Do you remember what your switch was rated for? The biggest key switch I could find was only rated for 12A @ 28v DC and I'm a bit worried about it as I would hate for it to crap out miles from home. I've got some 14 ga. silicone wire coming so I can replace the cheesie thin stuff that came from GM. That should help getting a bit more power to the road.

[biohazardman]

The rocker type switch is rated at 12v 30A has many miles and likely a bit of moisture in it.  Picked it up at radio shack it was a bit larger than I wanted but an easy install as it only needed a .5 inch hole to install.  I put another one in today and went to 30A on the fuse as they seem to blow under load on accelerating a bit to easy.  Did 11+ miles on the bike today with no problems got to love the torque for sure.  The bike managed 17mph on hills that used to take it down to below 12.  I had the throttle wide open on the trip and the Lifepo4 36v was at 39.4 but the SLAs were down to 9.5. I now have three broken spokes and I am really needing some stainless 12 gauge replacements.  I know they are available but can't find them. I expected a bit more on the top end but was really after the hill climbing ability.  Still I can't figure out why it does not go faster the torque is there

[Nicobie]

I also wondered why the bike does not go faster. Most said it would go 26+ mph @48v

Maybe it's just wind resistance as I ride with the seat and bars high or as I mentioned, the skinny wires (~18ga) powering the hub motor. The more I think about it, I'll bet that it is the lead acid batteries at fault.

I'm going to look for a better key switch too...

Nick

[biohazardman]

I just finished my 48v conversion yesterday and I'm getting about the same results, 23.4 mph with more torque. My range is down about 15% but that might be because I was a bit 'throttle happy'. I'm using 4 x 10Ah SLA batteries and am able to pull 4.7Ah out of them before the motor cuts out bad. My Watts Up meter shows a high of 38A (momentary) used and at full throttle it shows around 31A. I run a 30A fuse and it hasn't blown yet. Even though I didn't check real close, I didn't find anything getting warm. I need to check what voltage it runs at with a full 53.4v charge. I might have a wiring problem as I think it showed only 46v crusing on a full charge. Even though the batteries are only 10Ah I don't think they are the problem as they only have about a dozen charges on them. But they might be as I really don't think SLA's are good for 3c (or even 2c). Can't wait until I can afford 20Ah of LiPo4's.

Do you remember what your switch was rated for? The biggest key switch I could find was only rated for 12A @ 28v DC and I'm a bit worried about it as I would hate for it to crap out miles from home. I've got some 14 ga. silicone wire coming so I can replace the cheesie thin stuff that came from GM. That should help getting a bit more power to the road.

More on the switch, I tore it apart, it is not built well and pushing the wire terminals on pushes the switch terminals far enough up inside so that it dies not disconnect completely when turned off.  It's getting hard to find anything that is good anymore?  Whatsupwhidat?