Lithium batteries on ebay

[Robjohnb]

Does anyone know if these ebay battery packs deliver the capacity as stated?

http://www.ebay.co.uk/itm/111460971343?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Regards, Rob

 

[KirstinS]

No reason why not - pack size and weight mean it doesn't have to contain expensive cells

However - it's almost certainly no good for ebiking use (if that's your intention)

The packs won't be able to give enough amps and will sag horribly

 

[Robjohnb]

Thanks for the comment.
If it can deliver 9.8amps at 12V (will use 3 in series) I'll be very happy.
My existing pack is 7.2amps/36V feeding a BMSbattery Q100H, some sagging on hills.

 

[KirstinS]

I think you may be confusing capacity with c rate

Or in my way of thinking - the size of the tank with the size of outflow pipe

 

[KirstinS]

I can't see that 9.8amp rating anywhere . Is that max or continuous ?

 

[KirstinS]

These 9800mah packs seem to generally have a 2amp rating

I'm afraid this isn't enough by some margin

 

[OldFart]

There is a clip on youtube showing the insides of one of those packs.

What your basically getting are phone batteries that are 2100mAh max.

7 Wh.

The wiring to the switch inside wont take much current either,

 

[Robjohnb]

Is that the russian speaking youtube clip? if so, the cells as you say are 2100ma (guessing at 3.7v). But how many cells in the pack? 3x4?

 

[OldFart]

I assume 3 to give 12.6 volts. I had to click the HD button to be able
to read the writing on the battery he took out.

There are a few russian video's regarding other batteries with
a similar rating. Turns out they all seem to be 2000mAh nowhere
near the 9800mAh they claim to be.

They also look like phone batteries so the current draw wont me up
powering motors.

 

[Robjohnb]

Had a further search on the web and appears these are 6 lipo cells at 3.7V (4.2V max) 2100mA each cell. As a pack, 11.1V (12.6v max) at 4200mAh.
Additionally, wiring only good for low current and there's no cell balancing (BMS).
Thanks for the feedback though.

 

[OldFart]

Possible some sellers have packs with just 3 batteries in to save more money.
Feedback on Ebay said the pack was under 2Ah.

 

[OldFart]

I went for the HobbyKing Zippy packs. A pair of 5s 4Ah packs to start me off.

I think it was just under £50 with delivery.

 

[Robjohnb]

HobbyKing, looks good, thanks. Have you also used a BMS for them?

From my avatar picture, I have 40 li-ion cells wired 10s 4p. Taken from laptop battery packs. No idea what peak current it can deliver, it does sag somewhat on the hills.
How are you finding the Zippy packs?

 

[OldFart]

I have not used them yet. Only recently bought my " Thing "
£20 off ebay..

My thread about it. Pictures from page 3.... http://www.pedelecs.co.uk/forum/threads/scooter-moped-style-legal.19153/


Its currently still being painted. Although i will start to rebuild it this week.

It currently has 3x 10Ah SLA's which are damn heavy. The Zippy
batteries should be 1/3rd of the weight, Even upto about 12Ah.

So far i have spent £100 on it. Half of that were the batteries and the other half paint, Screws and clips.

I went for the 5s packs because my charger only goes upto 6s. And i got fed up of trying to find out which 10s packs could be charged as 2 5s packs.

The 5Ah batteries came in at an extra £15. So i decided to stick to the 4Ah. Under £50 to double my capacity instead of £60.
Whether it works out cheaper i dont know but it sounds cheaper

 

[Robjohnb]

ok, looks like cost is your key here. Seems a heavy bike though.
My effort cost about £400.

 

[OldFart]

I will weigh it when i start assembling. But the plan is to ditch the SLA's as soon as i know how far the Zippy packs will take me and as soon as i know that its all in working order on a decent run.

We only took it around the block a few times before i stripped it to paint it.
Perfectly flat around the block also, No hills.

Thats going to be the deciding factor on what to do next.

Odd sized wheels though. 18". Not seen many tyres or hub motors in that size.

Dumping the SLA's should save me 10 - 12kg.