CUDAcores89
1 W
- Joined
- Aug 28, 2016
- Messages
- 51
Hey folks, I haven't been on here in a really long time but I decided to stop in because well, I have a problem.
Currently I own an ebike. I ride the bike to and from where I work every day. The ride itself is a round trip of 20 miles. My system bike is a 1000w front-wheel drive I bought off ebay that I have been using for about a year now, and it works great. I use a 12S DIY ebike pack I made from Samsung 28A 18650 cells I got for about 17 cents a cell.
The pack itself is a 12S8P 44v 22.4AH battery pack I hand-built from some laptop batteries I got at my local recycling center.
I frequently visit my local computer recycling center and they sell things to me by the pound. One day a company had brought in an entire pallet of NEW in box HP 6-cell laptop batteries that had these Samsung 28A 18650 cells inside, each laptop battery had 6 cells. I asked how much they wanted for them they said "$1.50 a pound" . I went and bought 100 packs and gutted 20 of them to build my battery. the rest I sold on ebay and made a nice profit.
Currently I split the pack electrically into two 6S packs and charge it with a turnigy accucell 6. The problem is charging it this way is veeeerrrryy slow, and it usually takes so long to charge that I frequently wake up in the morning after plugging it in overnight and the pack is still charging. :x
It looks like I will have to find a faster way to charge my pack. Here is what I am thinking:
1. Buy a 1000w lipo charger and power it with server power supplies found at my recycling center.
This option is the most expensive. At my recycling center I find 12v 40-60A server power supplies from working machines all the time and I can get them for roughly $1 a piece. I would buy a very expensive 1000w lipo charger like a icharger 3010b or a cellpro powerlab 8. I then buy 2-3 server supplies for about $3 and run the charger off that. This would allow me to slow charge or fast charge my pack. I could also reduce the cell end voltages to extend the packs lifespan further.
2. Get a meanwell power supply. I could also buy something like a meanwell 48v 10A power supply and adjust the trimpot to my chosen end voltage. This would cost less than the icharger, but it would only be able to bulk charge the pack, and it would be annoying to adjust the end voltage every time I wanted to change it with a tiny screwdriver.
3. buy this DC-DC converter from aliexpress and hook it up to a bunch of server power supplies.
This one would probably cost me only about $25 in parts. I could buy this B900w digital DC-DC boost converter from aliexpress for around $18:
https://www.aliexpress.com/store/product/DC-Converter-High-Precise-LED-Control-Boost-Converter-B900W-Input-8-60V-to-10-120V-900W/2338265_32725667572.html
Then hook up a 48v DIY power supply made form 4 server power supplies. This one would allow me to charge the pack at probably around 450-500w (with these Chinese converters take the claimed number and divide it by two) and I could also easily adjust the end voltage and current. However I would not be able to balance charge the pack. Although that being said, I have measured my ebike pack before and after running it on a full cycle, and the cells do a very good job of staying within about 0.02-0.03v of eachother.
Right now I am leaning towards option 3 because it does almost everything I am looking for, but there might be something I have overlooked.
which one should I do? Or is there something even better I haven't thought about?
Currently I own an ebike. I ride the bike to and from where I work every day. The ride itself is a round trip of 20 miles. My system bike is a 1000w front-wheel drive I bought off ebay that I have been using for about a year now, and it works great. I use a 12S DIY ebike pack I made from Samsung 28A 18650 cells I got for about 17 cents a cell.
The pack itself is a 12S8P 44v 22.4AH battery pack I hand-built from some laptop batteries I got at my local recycling center.
I frequently visit my local computer recycling center and they sell things to me by the pound. One day a company had brought in an entire pallet of NEW in box HP 6-cell laptop batteries that had these Samsung 28A 18650 cells inside, each laptop battery had 6 cells. I asked how much they wanted for them they said "$1.50 a pound" . I went and bought 100 packs and gutted 20 of them to build my battery. the rest I sold on ebay and made a nice profit.
Currently I split the pack electrically into two 6S packs and charge it with a turnigy accucell 6. The problem is charging it this way is veeeerrrryy slow, and it usually takes so long to charge that I frequently wake up in the morning after plugging it in overnight and the pack is still charging. :x
It looks like I will have to find a faster way to charge my pack. Here is what I am thinking:
1. Buy a 1000w lipo charger and power it with server power supplies found at my recycling center.
This option is the most expensive. At my recycling center I find 12v 40-60A server power supplies from working machines all the time and I can get them for roughly $1 a piece. I would buy a very expensive 1000w lipo charger like a icharger 3010b or a cellpro powerlab 8. I then buy 2-3 server supplies for about $3 and run the charger off that. This would allow me to slow charge or fast charge my pack. I could also reduce the cell end voltages to extend the packs lifespan further.
2. Get a meanwell power supply. I could also buy something like a meanwell 48v 10A power supply and adjust the trimpot to my chosen end voltage. This would cost less than the icharger, but it would only be able to bulk charge the pack, and it would be annoying to adjust the end voltage every time I wanted to change it with a tiny screwdriver.
3. buy this DC-DC converter from aliexpress and hook it up to a bunch of server power supplies.
This one would probably cost me only about $25 in parts. I could buy this B900w digital DC-DC boost converter from aliexpress for around $18:
https://www.aliexpress.com/store/product/DC-Converter-High-Precise-LED-Control-Boost-Converter-B900W-Input-8-60V-to-10-120V-900W/2338265_32725667572.html
Then hook up a 48v DIY power supply made form 4 server power supplies. This one would allow me to charge the pack at probably around 450-500w (with these Chinese converters take the claimed number and divide it by two) and I could also easily adjust the end voltage and current. However I would not be able to balance charge the pack. Although that being said, I have measured my ebike pack before and after running it on a full cycle, and the cells do a very good job of staying within about 0.02-0.03v of eachother.
Right now I am leaning towards option 3 because it does almost everything I am looking for, but there might be something I have overlooked.
which one should I do? Or is there something even better I haven't thought about?