Is this worth it? New 18650 Cells @1.75 each delivered.

[silverheels]

On Ebay it would seem there are a number of 'New' Laptop batteries with 12 Cells for approx $21 delivered (within the US):

Example:
Title: Genuine Toshiba Satellite P10 P15 Laptop 12 Cell 6450mAh Battery PA3307U-1BRS:

"Genuine Toshiba Satellite P10 P15 Laptop 12 Cell 6450mAh Battery PA3307U-1BRS
Alt. Part Numbers: PA3307U-1BAS, PA3307U, PA3307U1BRS, PA3307U1BAS, K000009380, K000009510, K000009400, GC86503SAM0

This Toshiba Primary Battery Pack is a 12-cell, rechargeable, removable, lithium-ion (graphite) battery designed to work with Toshiba Satellite P10/P15 series portable computers. Always on the road? Add extended power capabilities to your portable computer with an additional battery pack now. "

Volts 14.8V
mAH 6450mAH

Project:
I'm looking to build a large battery pack for a Torqeedo 1003 outboard.
The original pack is an 8s8p 18650 of 530 watt/hr (approx 2.2 ah per cell).
Would it be reasonable that the above Laptop battery cells would have a similar life, and deliver similar performance over time?

Any opions out there ( )?

Here's a link to an Ebay auction (for what it's worth): http://www.ebay.com/itm/172098481432?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

 

[silverheels]

Or less:

12 cells (2600 mah) for <$18.00

Ebay listing:
New 12-Cell 14.8V 7800mAh Laptop Battery for HP Pavilion DV8 DV7 HDX18 Series
Link: http://www.ebay.com/itm/New-12-Cell...084606?hash=item1ea436f77e:g:-TgAAOSwQTVV98iZ

 

[Punx0r]

They might work, but you will need to discharge them at 0.5C or less, might have to bypass the internal BMS and you have to consider they might have been sat on a self for a couple of years.

 

[silverheels]

Good points.

Planning to purchase 12 batteries (approx $210 US) for 144 cells. Of which I'm hoping >120 cells in ok shape.
After testing each cell (to check capacity/health) I'll build a(an?) 8s15p pack that uses the Torqeedo BMS.

8s15p Pack info:
Nominal: 29.6 v (max 33.6v).
Power: 39 a/hr (2600 mah per cell [depending on cell health!!!] x 15p).
Useage:
Max discharge is 1000 watts - 34a
Typical use is @300 watts - approx 10a).

So, perhaps not quite 1c at max power and <0.5c in normal use.

Does the electrical/math check out ok?
Is it realistic to think that 90% of the cells will be within 10% of intial spec?

Thanks for any input!

 

[Hillhater]

.
Planning to purchase 12 batteries .....
Is it realistic to think that 90% of the cells will be within 10% of intial spec?

Thanks for any input!

Yes the maths is OK but....

Beware !
Those are not genuine HP packs. They are "replacement" equivalents of unknown origin capacity or quality.
Buy one and test it to see what you are getting.....and do not expect them all to be the same !
I tried the very same thing , 12 cell laptop pack (new?) , but found the cells had less than 0.5Ahr capacity ! ( just enough to make you think it's working !)
Also be aware that you cannot check the cells without breaking the pack open...and then you cannot return them for a refund if they are crap.
Much less risk if you find genuine original Manufacturers packs (new)
Remember......no free lunch in this game ! :wink:

 

[silverheels]

Yet more good advice.
1 Battery ordered. I'll post the test results.
Thanks!

 

[phild]

I bought 4 of these

http://www.trademe.co.nz/Browse/Listing.aspx?id=1023983850

BUT ... after dissassembling charging the cells and discharging I found the capacity of each cell to be between 769mah and 1312mah - so not my finest purchase. Obviously couldn't return after breaking the packs up.... but don't bother. Buy proper cells from one of the suppliers here.

 

[kdog]

You'll almost certainly have to disassemble them (for all sorts of reasons) There's considerable work involved in rebuilding testing etc to get a new pack. unless they are top notch cells (highly unlikely) it will prob be better buying new quality cells for $3-5usd ( (maybe even with tabs pre welded) a bms and charger and build your own pack. I reckon the end result will be better than hacked apart, low c rate, old 18650s from computer packs.
You won't regret it- paddling home will suck big time!! :|
Torqueedo- nice!
K

 

[iangreenhalgh]

If you get good packs the cells are exactly the same as you can buy off the shelf. For instance, I just bought a load of new old stock HP battery packs dirt cheap. I first bought one to test and it had 8 pink Samsung 26H 2600mAh cells. Tested them by charging to 4.2v in a nitecore charger then discharging at 1A in my IMAX B6; they all still have at least 2300mAh left so I'm happy. Works out at 0.32ukp per cell; new Samsung 26FM cells are a little over 2.00 ukp each from Gearbest, more elsewhere so I saved a lot of money.

 

[ecycler]

Not even near worth it in my opinion.