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Post by papaof2 on Sept 27, 2023 13:53:10 GMT -6
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Post by gipsy on Sept 27, 2023 14:38:45 GMT -6
What if you peddle to help? What if you put a solar panel on the back? What if you weigh more the 170, like me or less like the wifee? I know (Look it up).
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Post by papaof2 on Sept 27, 2023 17:24:40 GMT -6
The first link includes options for almost everything - even your height above sea level.
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Post by feralferret on Sept 27, 2023 20:30:11 GMT -6
Unfortunately ebikes seem to have a history of catching on fire lately. I suspect some of them have el cheapo poor quality batteries and chargers.
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Post by gipsy on Sept 27, 2023 20:47:18 GMT -6
See I knew it. Look it up in different words.
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Post by papaof2 on Sept 27, 2023 23:24:59 GMT -6
Unfortunately ebikes seem to have a history of catching on fire lately. I suspect some of them have el cheapo poor quality batteries and chargers. Two options: 1) Buy from a vendor known not to overwork or overcharge the batteries. Not sure if any reviewer / tester pays attention to useful bits like that to be able to say "safest" instead of "fastest" or "most powerful". 2) Build your own battery pack. LiFePO4 cells are more commonly available in 26650 format which is a little bigger than the usual 18650 lithium-ion cells, but there are some VERY powerful LiFePO4 cells that would allow building a battery pack with the same voltage rating but with higher current capability before overheating and there are BMS units with external temperature sensing capability (temp sensor mounted on or inside the battery pack). You might have to 3D print a new battery case (slide to fit the original mount and have the lock in the right place but the overall case larger to hold the 26650 LiFePO4 cells (instead of the 18650 lithium ion cells) - maybe a pregnant battery pack with a big belly? ;-) batteryhookup.com/products/12v-module-with-8x-a123-26650-lifepo4 Go there and bring up the datasheet for the cells used. $12 per module plus $12 shipping for one and maybe $0.50 to $1.00 for each additional module or about $60 for the pieces to build a 48 volt battery pack. If you need a 36 volt battery pack, three modules + shipping is about $48. This is a 12 volt 4s2p battery pack made up of cells rated for 70 amps continuous discharge and it has two rows of those cells in parallel so 12 volts at 140 amps (IF you beef up the nickel strips that connect the cells together). But at 48 volts, 20 amps is almost 1000 watts so you could just wire four modules in series and add a good BMS. The maximum fast charge rate is 10 amps UNTIL it reaches 80% SOC and then taper it down. These cells are the same physical size (26650) but capable of higher discharge than the ones I used (in 4s3p config) to power an inverter to run a 440 watt halogen lamp from a 12 volt battery I can hold in one hand. IF you do intelligent things with the DIY battery pack (limit charge current to the cell's specs, limit charge temperature, use a BMS that limits the discharge current to a safe value AND watches the temperature during use) these cells are not likely to catch fire. Your DIY battery pack may be 50% bigger than the original lithium ion 18650 pack but it will probably have more total power capability than the original pack and be much less likely to catch fire than the OEM battery pack. If you use surplus cells like these, the DIY LiFePO4 pack will likely be under $100 which is a price I doubt you'll find on any of the ebike battery sales pages. If you don't want to 3D print a new case, just wrap the battery pack in several layers of Kapton tape for insulation and to hold things together and use some zip ties to mount it to the ebike... 3) Buy an aftermarket charger or build your own. All the hardware needed for that is available from banggood.com and aliexpress.com. Just buy a device rated for twice the charge power you need and throttle it down to a safe level for the battery pack. They offer 48 volt, 20 amp power supplies so add voltage regulation and current limiting and run it at 48 volts, 10 amps. Then your charger won't overheat and die. If you're curious about building the battery pack or the charger, I can look up the piece parts and provide a list. No, I'm not interested in starting a business building the "Best in the West" ebike battery packs and chargers. If you want to start that business, I'd like 5% of the first year's profits as a finder's fee ;-) |
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