George S.
Well-Known Member
I've used LiPo packs from Hobby King. You just get the cells in a pack with a power lead and balance leads. The only problem is that they are Lipos, which is probably the least safe chemistry.
I ran across a company, Titan, that is making packs with the Panasonic (Sanyo) GA cells. I've seen packs on Amazon. This is 6 cells in series to make 22 volts. You would need 4 packs to make a 7 AH ebike battery that would be about 44 volts. There are cheap connectors that would allow assembly of an ebike pack in maybe a minute. The company sells these packs for less money, as a brick or as a double row. It's not the season to build an ebike battery.
There's no BMS. The experimenters who use LiPo face the same issue. The chargers use the balance leads while charging, and RC chargers are very sophisticated. You can monitor the voltage as you ride, with a cheap display, to avoid over-discharge. How much monitoring you need depends on how much you are pushing the pack. Most of this requires a level of knowledge that is easily acquired. For example, a 44 volt battery should work fine, but the battery monitor for a 36v or 48v system will be confused.
I got an informative and friendly email from the president of Titan. They still have a very low profile and I was wondering what kind of traction they were getting. Trent said they were getting a lot of orders and keeping very busy. They are active in Utah, Idaho, and HQ in Arkansas, which is good to hear.
It's more proof that the 3500 mah GA cell is the super cell, at least for this year. I prefer modular systems, if possible, to isolate problems. With these GA type 18650 cells, it is much easier to carry two battery packs. Luna makes a 52v pack with the GA's, a mini pack, for $314. Since there are 28 cells in the Luna Mini, it works out to $11 per cell. The Titan is a bit cheaper, around $8 per cell. The Luna has a BMS. Grin has their 10 cell mini battery, but it runs $12 a cell and uses lower capacity cells. The new tougher Luna Shark with 52 cells runs about $9 a cell.
I ran across a company, Titan, that is making packs with the Panasonic (Sanyo) GA cells. I've seen packs on Amazon. This is 6 cells in series to make 22 volts. You would need 4 packs to make a 7 AH ebike battery that would be about 44 volts. There are cheap connectors that would allow assembly of an ebike pack in maybe a minute. The company sells these packs for less money, as a brick or as a double row. It's not the season to build an ebike battery.
There's no BMS. The experimenters who use LiPo face the same issue. The chargers use the balance leads while charging, and RC chargers are very sophisticated. You can monitor the voltage as you ride, with a cheap display, to avoid over-discharge. How much monitoring you need depends on how much you are pushing the pack. Most of this requires a level of knowledge that is easily acquired. For example, a 44 volt battery should work fine, but the battery monitor for a 36v or 48v system will be confused.
I got an informative and friendly email from the president of Titan. They still have a very low profile and I was wondering what kind of traction they were getting. Trent said they were getting a lot of orders and keeping very busy. They are active in Utah, Idaho, and HQ in Arkansas, which is good to hear.
It's more proof that the 3500 mah GA cell is the super cell, at least for this year. I prefer modular systems, if possible, to isolate problems. With these GA type 18650 cells, it is much easier to carry two battery packs. Luna makes a 52v pack with the GA's, a mini pack, for $314. Since there are 28 cells in the Luna Mini, it works out to $11 per cell. The Titan is a bit cheaper, around $8 per cell. The Luna has a BMS. Grin has their 10 cell mini battery, but it runs $12 a cell and uses lower capacity cells. The new tougher Luna Shark with 52 cells runs about $9 a cell.
