Hi, I'm Greg. I'm the new guy.
I've been wanting to get into e-bikes for a while, but could never decide if I wanted to buy a hub motor kit or do something custom or what. Recently I found a crazy e-bike (sans battery pack) for a good deal and picked it up. It turned out to have a broken brake cutout switch, but otherwise seems in good shape. It also rides pretty well without power.
Apparently the bike is called "Xingyueshen Lvsehuanbaodiandongche XYD2000-36 STAR & MOON" but the "Xingyueshen Lvsehuanbaodiandongche" must have been on the battery pack, as it isn't on mine. You see in the photo that I have it somewhat torn apart, and was testing it using 4 8.4V NiMH battery packs.
Now that I have the cutout switch fixed, I want to build a battery pack for it. I have 30 of those 8.4V NiMH packs, they are 2000mAh, and would like to build a 14Ah 36V battery pack. My plan is to build the box with two sections of PVC downspout side by side, they fit perfectly where the original pack was.
Here are my questions.
1.) 36V= 4*8.4V + 2*1.2V, so I add two more 1.2V cells to the four 8.4v series battery packs to get 36V, right?
2.) The battery packs have wire leads coming off them, what is the best way to daisy chain the packs? Solder only, solder and wirenut? something else?
3.) The battery packs each have a thermistor on them, and the smart charger that I bought has a third wire (for temp sensing), do I just hook it up to any of the thermistors? Do I have to worry about temp curves or calibration?
4.) Does the battery box need venting?
5.) Mathematically it doesn't matter if I do seven 36v packs in parallel, or if I do seven 33.6v packs in parallel and seven 2.4v packs in parallel and then put those two bundles in series to get 36v. Does it matter in practice? Although it sounds more complicated, it would actually be easier to wire it up with 33.6v and 2.4v bundles.
6.) Best type of power connector to put on the box to interface with the controller?
7.) Fuse(s)?
Thanks in advance for any advice you can throw my way.
Greg
I've been wanting to get into e-bikes for a while, but could never decide if I wanted to buy a hub motor kit or do something custom or what. Recently I found a crazy e-bike (sans battery pack) for a good deal and picked it up. It turned out to have a broken brake cutout switch, but otherwise seems in good shape. It also rides pretty well without power.
Apparently the bike is called "Xingyueshen Lvsehuanbaodiandongche XYD2000-36 STAR & MOON" but the "Xingyueshen Lvsehuanbaodiandongche" must have been on the battery pack, as it isn't on mine. You see in the photo that I have it somewhat torn apart, and was testing it using 4 8.4V NiMH battery packs.
Now that I have the cutout switch fixed, I want to build a battery pack for it. I have 30 of those 8.4V NiMH packs, they are 2000mAh, and would like to build a 14Ah 36V battery pack. My plan is to build the box with two sections of PVC downspout side by side, they fit perfectly where the original pack was.
Here are my questions.
1.) 36V= 4*8.4V + 2*1.2V, so I add two more 1.2V cells to the four 8.4v series battery packs to get 36V, right?
2.) The battery packs have wire leads coming off them, what is the best way to daisy chain the packs? Solder only, solder and wirenut? something else?
3.) The battery packs each have a thermistor on them, and the smart charger that I bought has a third wire (for temp sensing), do I just hook it up to any of the thermistors? Do I have to worry about temp curves or calibration?
4.) Does the battery box need venting?
5.) Mathematically it doesn't matter if I do seven 36v packs in parallel, or if I do seven 33.6v packs in parallel and seven 2.4v packs in parallel and then put those two bundles in series to get 36v. Does it matter in practice? Although it sounds more complicated, it would actually be easier to wire it up with 33.6v and 2.4v bundles.
6.) Best type of power connector to put on the box to interface with the controller?
7.) Fuse(s)?
Thanks in advance for any advice you can throw my way.
Greg
