Sunder
10 MW
Hi All,
As of yesterday, I am now the proud owner of a Vectrix VX-1. I bought it off another forum member "heathyoung". Full thumbs up to him, the transaction was very smooth and straight forward, and he's been a fair bit of help with technical knowledge.
The thing is, I bought it knowing full well that the battery pack is on its last legs. The bike in theory should be capable of about 40km right now with no mods. (Heath mentioned 22Ah left @ 60wh/km). The thing is, the bike can pull 150A-200A, but the battery is currently only offering 65A. I also suspect that means that the range is shortened by sagging and hitting LVC, rather than complete loss of capacity, so boosting voltage *may* boost range.
I've nutted out a few options, but I'm in a quandary, as I have a bit of a limited budget at the moment, so it's a battle between spending twice, or doing it right the first time. Complicating that is that while I'd like to keep the bike for a long time, I am going to the UK for 2 years in 2 years time. So either a pack that only lasts 2 years and is cheap (LiPo) or will still be good when I return (LTO) is ideal. LiFePo4 is somewhere in between.
The specs I need are:
95% of my trips will be 30km round trip.
5% of my trips will be up to 80km round trip, but I can use a car or taxi in those cases - Call it nice to have rather than a need.
Prices are in AUD
Just a note on the comments and highlights:
1. The LTO batteries are Toshiba SCIB High Power Density - I found some for sale cheap on eBay, but they've since been pulled - they still exist on Aliexpress, but I'm not sure I can trust the seller there - low ratings. Some people do BMSes for LTO, but it seems like it's mostly under/over charge protection. It seems balancing is not required - probably because LTO are tolerant to over/under discharge.
2. BMSes that handle 36S @ 150A+ are rare as hens teeth - so I can use a smaller BMS to balance and charge only - A risk, but I know the batteries are good for far more than the controller with take, so only a small risk.
3. The LiPo Range extender because they're not LiHV cells will get overcharged by the charger - I can either charge through the BMS and have it cut off all the time, or else lower the charger, and lose a bit of capacity from the main pack.
4. The replacement pack I found seem to use 1C cells, which means it won't give enough current. Either I need to also apply a booster pack, or else build one myself out of 3C cells - the price appears similar, except I need to do the work. I chose this under-speced pack, because it's prebuilt and there's only one hard case around the entire pack, rather than around each cell, which gives you more room in the battery bay to actually fit a 60Ah pack. If you use individual hard case cells, you can only fit 40Ah in there.
Wish I could start a poll so that people could vote without posting (and easily collate the information), but it seems polls are disabled on this forum. If you could just post even which option you'd choose if you were me, and optionally why, this would help me immensely.
Thanks in advance.
As of yesterday, I am now the proud owner of a Vectrix VX-1. I bought it off another forum member "heathyoung". Full thumbs up to him, the transaction was very smooth and straight forward, and he's been a fair bit of help with technical knowledge.
The thing is, I bought it knowing full well that the battery pack is on its last legs. The bike in theory should be capable of about 40km right now with no mods. (Heath mentioned 22Ah left @ 60wh/km). The thing is, the bike can pull 150A-200A, but the battery is currently only offering 65A. I also suspect that means that the range is shortened by sagging and hitting LVC, rather than complete loss of capacity, so boosting voltage *may* boost range.
I've nutted out a few options, but I'm in a quandary, as I have a bit of a limited budget at the moment, so it's a battle between spending twice, or doing it right the first time. Complicating that is that while I'd like to keep the bike for a long time, I am going to the UK for 2 years in 2 years time. So either a pack that only lasts 2 years and is cheap (LiPo) or will still be good when I return (LTO) is ideal. LiFePo4 is somewhere in between.
The specs I need are:
95% of my trips will be 30km round trip.
5% of my trips will be up to 80km round trip, but I can use a car or taxi in those cases - Call it nice to have rather than a need.
Prices are in AUD
Just a note on the comments and highlights:
1. The LTO batteries are Toshiba SCIB High Power Density - I found some for sale cheap on eBay, but they've since been pulled - they still exist on Aliexpress, but I'm not sure I can trust the seller there - low ratings. Some people do BMSes for LTO, but it seems like it's mostly under/over charge protection. It seems balancing is not required - probably because LTO are tolerant to over/under discharge.
2. BMSes that handle 36S @ 150A+ are rare as hens teeth - so I can use a smaller BMS to balance and charge only - A risk, but I know the batteries are good for far more than the controller with take, so only a small risk.
3. The LiPo Range extender because they're not LiHV cells will get overcharged by the charger - I can either charge through the BMS and have it cut off all the time, or else lower the charger, and lose a bit of capacity from the main pack.
4. The replacement pack I found seem to use 1C cells, which means it won't give enough current. Either I need to also apply a booster pack, or else build one myself out of 3C cells - the price appears similar, except I need to do the work. I chose this under-speced pack, because it's prebuilt and there's only one hard case around the entire pack, rather than around each cell, which gives you more room in the battery bay to actually fit a 60Ah pack. If you use individual hard case cells, you can only fit 40Ah in there.
Wish I could start a poll so that people could vote without posting (and easily collate the information), but it seems polls are disabled on this forum. If you could just post even which option you'd choose if you were me, and optionally why, this would help me immensely.
Thanks in advance.
