anyone in the UK interested in a 48V GM battery

[DirtyGinge]

Not that  I mean to take sales away from any dealers, but as its very difficult to get batteries in the UK

The story is, I purchased the kit about 2 months ago, however its not really up to my daily 40 mile journey towork and back, so I built my own batteries, and have now ordered a rear Magic Pie to match the front to improve torque efficiency

Im thinking of selling the original 48V, as technically its surplus, to pay for the rear MP, anyone interested ?  ( uk only please)

PM is probably best, and no offence meant to anyone who might be offended, or any forum rules I may have broken, sorry

[Andrew]

hi m8
how knackered is the battery? i'm interested

[DirtyGinge]

well to be honest, I thought it was a little short on range, however according to the "little writing" on the batteries, the 12ah rating is based on the cells reaching 2.5v each, which they never will due to the BMS cutting in.....

Im getting 20 Miles range for sure....its lost a little of its new edge, but charges according to the CA to 54.4...

Is there any tests you would like me to do to check how it is for you, as you would expect it to be, range etc...i can do a gps track on the bike, so you could view range and speed of the battery pack etc ?? ( www. endomondo.com)
 
Also would be happy to sell to you through ebay, in which case, my seller reputation would be in your hands.......a little guarantee in your favour

From what I figure, the 12ah batteries sold by GM are actually 9ah batteries when the BMS kicks in  ( 42v/13 = 3.2 per cell, but ah rating is based on 2.5v poer cell....2.5/3.2  = 78 percent usage before bms kicks in, in which case 12ah * .78% =9.3 ah...if that makes sense ??

anyway, I have pulled 7.5 ah out of this no problem

the battery is only 2 months old, and under a year warranty from alienbikes.co.uk

regards

[Andrew]

i doubt I can offer you what you're probably after, but out of curiosity where are you in the UK and what kind of price are you looking for?

Andrew

[Bikemad]

From what I figure, the 12ah batteries sold by GM are actually 9ah batteries when the BMS kicks in  ( 42v/13 = 3.2 per cell, but ah rating is based on 2.5v poer cell....2.5/3.2  = 78 percent usage before bms kicks in, in which case 12ah * .78% =9.3 ah...if that makes sense ??

That 9.3Ah doesn't sound right to me, if it is discharged down to 3.2V per cell, it should be delivering around 98% of its rated capacity (not 78%) which I reckon to be at least 11.75Ah (98% of 12Ah), and if you look carefully at the following discharge curve you will hopefully be able to understand why:



As each of these cells are supposed to produce "4.0Ah Minimum of rated discharge capacity after recommended charge", the actual capacity should be pretty close to 12Ah for the whole pack if the cells are closely matched.

Alan
 

[DirtyGinge]

to be honest I must go out and do a full run on the battery, and see where I get to, but after 8AH, I still had about 46v in the battery, so there's probably more to go

i was quoted 500 for a new battery from alienbikes, but realise this is way far of the actual value.......its surplus to me now, so 250-300 is in my mind initially ......what is it worth to you ? ( the far more important question )

Im based in windsor, berkshire in the UK

[Andrew]

thanks for getting back, to be honest, if it's not performing properly, it would be a bad idea for me to spend out on it.  Have you been back to Alien about the battery? can you prove that it is only giving out 7ah. Can they not test it? surely the battery comes with some length of warranty. You paid £200 more to buy from the UK dealer rather than off Gary or China, isn't that excess your insurance on the product?

[DirtyGinge]

well, im going away for christmas, so what ill do when I get back is charge it up, then go on a run with a gps tracker, to see exactly how she performs.....how about that... I did make initial enquiries with alien who reckon its fine, but yes it indeed has a full warranty until next November, so I have no concerns about the product failing, either for me or anyone else...

The part came as a complete kit from alien, but initially I enquired about a spare for the journey that I do and got that price quoted....

As stated, ill do the GPs track, nice day, average terrain, and run it at about 20mph until the first bms cut out......then post the gps stats so all can see the speed and distance covered if this seems a fair test of the ability...any thoughts

[GM Canada]

I think it depends on how hard you ride it as well. I usually get about 9 to 10 AH each from my pair or 48V12AH batteries. But thats full throttle with a heavy load ( no comment ) up and down hills. Putting along the lake at a more resonable speed on the level path I get more AH. Can't really give any details though as my bike is hanging from a hook for the winter  

Gary

[DirtyGinge]

Hi all, hope you have all had a good new year

wel, went for my test run, and it looks like I forgot one small detail - TEMPERATURE !!

for the last month at least, the uk has been basking in -10C to -20C, with me going to work at 4.00 in the morning, average -6C, what a difference that can make !

Test is performed with bike 40KG, rider 95KG ( christmas, cmon give me slack ), voltage set at 48v, NO REGEN ( I don't use regen, don't think its worth the risk of damage, my area is hilly

One golden motor, plus one home build to get me home once I LVC

test is concluded upon first LVC......plenty of hills and a variety of speed...battery put out 9.7 AH

( one slow speed section, went to go around lake, but so many walkers, decided it was not safe, little kiddies and doggies etc)
a very enjoyable ride ( temp 4C)

http://s1137.photobucket.com/albums/n510/dirtyginge/

[DirtyGinge]

Hi All
So tell me, as far as I figure in the specs below, the Ah of the battery is rated on discharge rate of 2.5V per cell  ( 13 series, making 32.5V per cell before empty)
Now as far as I can figure LVC cuts in for me about 41V per cell ( 41/13 = 3.15v) per cell, making as I estimate, the 12ah battery is actually a 10ah battery due to BMs

So is anyone actually getting higher than 10ah ?? ( referring to Bikemad's earlier post)

here is the post in the forum
Here are the full spec's on the cells used by Golden Motor.  They have no spec's on their full Battery Packs but, with a little math you can figure it out.
Lithium Ion Battery Cell
Product Details

Place of Origin     Jiangsu, China (Mainland)
Brand Name        GoldenMotor
Model Number     26650
Type                 Li-Ion
Application         Electric Vehicles
Size                  65mm
Voltage             3.8V
Weight              92g
Detailed Product Description
 
highest energy density
cell level safe design
cell weight: 92g only!!
long lifespan
Lithium ion rechargeable battery, 26650 size, LiPF6 electrolyte, Manganese Spinel structure cathode.
High energy density lithium ion battery cell.
Cell capacity: 3.8V 4AH
Cell diameter: 26.24 ± 0.16 mm (top end), 26.16 ± 0.10 mm (bottom end)
Cell height: 65.05 + 0.10/-0.15 mm
Cell weight: 92g

Cell specifications
 
1a. Rated charge(4A) Limiting 4.0 A, 120 min and constant 4.2V charge at 23±2°C.
1b. Recommended charge Reference 1a
 
2. Rated discharge Constant 0.8 A discharge until 2.5V at 23±2°C.
 
3. Rated capacity 4.0Ah Minimum of rated discharge capacity after recommended
charge.
 
4. Nominal voltage 3.8V Mean voltage during rated discharge after rated charge.
 
5. Shipping voltage 4.03±0.01V Nominal. Approximate state of charge = 80%.
 
6. Internal resistance at shipping 23±1 m? By AC 1 kHz.
 
7. End of charge voltage 4.20 ± 0.05V
 
8. End of discharge voltage 2.5V.  Discharge voltage used for determination of rated
capacity.
 
9. Charging time 120min Rated charge.
 
10. Maximum continuous charging current 6.5A
Maximum continuous discharging current 10A
Maximum pulse discharging current 40A
 
11. Operating temperature
Charging 0 ~ 45°C
Discharging -20 ~ 60°C

12. Storage temperature
-20 ~ 60°C
Recommended temperature for long term storage is
23±2°C
 
13. Shelf life 6 months Typical value at 23±2°C, from ship state.
 
14. Self-discharge rate /month ?0.5%

For Your Reference
Don

[Webby]

Hi Ginge

As per our other thread - I'm interested and consider this SOLD  .

Speak to you soon.

webby