YESCOM USA 48V 1000W hub motor (ebay) slips on second ride

[wesnewell]

How much does Turnigy cost for 58v 26.4 AH

You need 14s for 58.8V. About $125 for 5ah, so about $725. Then you need a 14s charger. That's another $200 or so with a PSU. Or, go 15s and parallel charge your batteries to 95%. There's just lots of options to chose from. Cost will be about the same for the lipo either way.

 

[parabellum]

How much does Turnigy cost for 58v 26.4 AH

You can also go cheapo with 12s 30A for about 385U$+ shipping. Will be ~50V fully charged. Using following cells.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=15521

Or if you are technically right, not afraid of lipos and are confident to brake inside the pack (which is kinda similar to working with laptop batteries). You can buy 23 of same for 492U$ + shipping. You open up 5 packs and remove spare cell to come to 15S (or 14S) on all your parallel strings and make 6th pack of those cells. I did it on my BMX bike but for recycling packs that came with dude cells. Bulk charging is fine but kind of PITA for balancing from time to time, I balance 1st lower 8s pack, then higher 7s or vice-verse. Unfortunately no BMS I could recommend for lipos right now. Hopefully GGoodrum will finish hes soon.

 

[adobian]

I've seen laptop battery, original OEM COMPAQ/HP with 6600mAH 14.5v for $12.99 each. Would lithium-ion last longer than lipo?

 

[parabellum]

I've seen laptop battery, original OEM COMPAQ/HP with 6600mAH 14.5v for $12.99 each. Would lithium-ion last longer than lipo?

I doubt they will, but you can try it and start "Yet Another Laptop Battery Pack Build! 2" tread. I personally would need >90kg on those cells to correspond my peak discharge habits, that why I better will not even think about.

 

[adobian]

How much does Turnigy cost for 58v 26.4 AH

You can also go cheapo with 12s 30A for about 385U$+ shipping. Will be ~50V fully charged. Using following cells.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=15521

This price seems pretty reasonable. I wonder why. It seems to be cheaper than other Lipo packs.

 

[parabellum]

How much does Turnigy cost for 58v 26.4 AH

You can also go cheapo with 12s 30A for about 385U$+ shipping. Will be ~50V fully charged. Using following cells.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=15521

This price seems pretty reasonable. I wonder why. It seems to be cheaper than other Lipo packs.

Have 40 of them, no complains. Only 2 came with 1 dude cell each. Your only problem can be getting them, they stay in stock for 1-2 days, then out again for 2-4 weeks. Guess why.

 

[adobian]

How could you tell if there is a dude cell?

 

[parabellum]

How could you tell if there is a dude cell?

My dude cells came little undercharged in respect to others, after you charge balance them and wait for few days, they will be less charged (in respect to others) again. Dude cell effect! The number of days and undercharge is dude multiple of the cell.

Edit: Capacity was same of other cells (even in charge discharge cycles), so ignore it.

 

[adobian]

I read that these Turnigy Lipo will last about 100 cycles. Is that true?

 

[parabellum]

I read that these Turnigy Lipo will last about 100 cycles. Is that true?

They can die in 20 cycles if you overcharge, undercharge and find a way to do it over designed C rates. Have killed nanotech 24s pack this way.

If you cycle them between 3.5V-4.12V, charge 1C (they are 5C max), discharge under 10C (which is full discharge in 6 min) and give them a kiss from time to time, like I do, I'm confident to get over 500 cycles to 80% of initial storage capacity. Have wide over 100 cycles on 24s 10Ah pack made of Turnigy hardcases, with no noticeable capacity loses and balancing in over every 20 cycles.

 

[adobian]

Does each hard case pack has built in BMS to prevent overcharging about 4.1V and over discharging to below 3.5V?

 

[parabellum]

Does each hard case pack has built in BMS to prevent overcharging about 4.1V and over discharging to below 3.5V?

No BMS, just packs in serial connection and bulk charged, few ES members, starting with LFP are translating BMS as " Battery murdering system" and I fully agree with them, all available BMS are BS. Only hope is http://endless-sphere.com/forums/viewtopic.php?f=14&t=30021&hilit=bms&start=90. Before that, you are your own BMS.

 

[adobian]

It looks like laptop batteries are better in a sense that they have already BMS built-in and proven to last a few years.

 

[parabellum]

It looks like laptop batteries are better in a sense that they have already BMS built-in and proven to last a few years.

You are maybe right, but I got Dell laptop battery that failed after 6 months of use, from other side HP battery that worked almost 2 years and I usually do not work of grid if having plug access.
I do not know how this BMS works, but I see a little issue. If you connect them in strings, you will not be able to balance connect them on cell nor pack level. So what happens if few random packs cut of in use, disabling several strings? You will be hammering remaining strings with higher C rate. Example you have enough strings to discharge at 1C, but when half of them shuts off, you are on 2C. Have you any idea how to avoid this scenario?

Have also seen several treads about laptop battery packs for bicycle use but do not remember any report of longevity. If you have seen some, please post a link

 

[adobian]

It does look like LIFEPO4 might be better deal overall, safe + longevity.. Maybe I should cut corners and save up money for a few months to cough up about $600.