Mad Professor
10 mW
Good day all.
As per the title I can't yet deside if it's better you build a pack or just buy a prebuilt pack ready to go.
This is not for my self, but for my father.
He build his own e-bike, and had been using 3x 12v 7ah SLA batteries.
But the SLA batteries have now had it, so my father brought a prebuilt DIY pack from a UK eBay seller, but this pack has failed within 3 months, and the seller and ebay are not intrested in helping, but I will save the details on that for another post.
So my father wants to get a new battery pack for his e-bike, but I keep on putting him off buying anything else, as I don't want him wasting any more money on bad battery packs.
His current setup is some unknown make 250w brushless hub motor, and an unknown make controller, Peak current load seems to be around 9Amps.
He mostly uses his e-bike in pedal assist mode, but does use the thumb thottle from time to time.
Most return trips are around 20-25 mile, and is out on the bike for aprox 2 hours.
I am guessing that my father will need a battery pack around the 15 to 20Ah Capacity.
I have been looking at building him a battery pack using laptop 18650 battery cells, but after reading SamTexas "Info on Laptop 18650 LiCo cells" post, it seems that the laptop cells are only rated for 0.5c continuous discharge, so a 2200mAh cell is only really good for 1100mAh continuous discharge.
So if I was to use the 18650 battery cells I would be needing at least a 136+ cells to make a 15Ah pack. and 180+ cells to make a 20Ah pack.
I have also been looking at the Turnigy 5000mAh 20C Single Cells.
Once again I would be looking at 30 Cells for 15Ah, and 40 Cells for 20Ah.
With both setups I will need a suitable BMS, and charger.
But I am still unsure what would be best, if we was to build or buy.
The other problem we have atm, is that alot of couriers within the UK, are very picky about shipping lithium cells.
So I would really like to know what other people suggest we should do?
Thanks for your time.
Best Regards.
As per the title I can't yet deside if it's better you build a pack or just buy a prebuilt pack ready to go.
This is not for my self, but for my father.
He build his own e-bike, and had been using 3x 12v 7ah SLA batteries.
But the SLA batteries have now had it, so my father brought a prebuilt DIY pack from a UK eBay seller, but this pack has failed within 3 months, and the seller and ebay are not intrested in helping, but I will save the details on that for another post.
So my father wants to get a new battery pack for his e-bike, but I keep on putting him off buying anything else, as I don't want him wasting any more money on bad battery packs.
His current setup is some unknown make 250w brushless hub motor, and an unknown make controller, Peak current load seems to be around 9Amps.
He mostly uses his e-bike in pedal assist mode, but does use the thumb thottle from time to time.
Most return trips are around 20-25 mile, and is out on the bike for aprox 2 hours.
I am guessing that my father will need a battery pack around the 15 to 20Ah Capacity.
I have been looking at building him a battery pack using laptop 18650 battery cells, but after reading SamTexas "Info on Laptop 18650 LiCo cells" post, it seems that the laptop cells are only rated for 0.5c continuous discharge, so a 2200mAh cell is only really good for 1100mAh continuous discharge.
So if I was to use the 18650 battery cells I would be needing at least a 136+ cells to make a 15Ah pack. and 180+ cells to make a 20Ah pack.
I have also been looking at the Turnigy 5000mAh 20C Single Cells.
Once again I would be looking at 30 Cells for 15Ah, and 40 Cells for 20Ah.
With both setups I will need a suitable BMS, and charger.
But I am still unsure what would be best, if we was to build or buy.
The other problem we have atm, is that alot of couriers within the UK, are very picky about shipping lithium cells.
So I would really like to know what other people suggest we should do?
Thanks for your time.
Best Regards.