12v 7ah batteries

[yobbo]

I have a very cheap source of 12v 7ah batteries, can I use these in a ebike application?

 

[amberwolf]

Need complete detail of batteries and application to begin to answer your question with any accuracy.

At least this:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
copy the list and paste it here in this thread, with your specific answers.


In theory you can use any battery of any kind or size for an ebike application, but some are only good for powering the lights, or even just running the clock on the cycle computer.

 

[yobbo]

Thanks Amberwolf

link http://www.gadgetcity.com.au/7ah-7-amp-hour-battery-agm-sla-ups-alarm-12v-rechargeable-p-2899.html?utm_medium=cpc&utm_source=getprice

These are generally used in back up to alarm systems,I was thinking of wiring 3 in series,which should give me 252w 36v

Will these have enough to power this Bafang 8Fun Electric Bicycle Bike eBike Mid Drive Conversion Kit 36v 250w BBS01B
on a GT hybid (13.5 kilo/30lb) bike with 26 x 1.75 road tyres ?

Edit Battery weighs 2 kilo/4.5 lbs x 3 = 6 Kilo/13.5 lbs

 

[yobbo]

Thanks Amberwolf

link http://www.gadgetcity.com.au/7ah-7-amp-hour-battery-agm-sla-ups-alarm-12v-rechargeable-p-2899.html?utm_medium=cpc&utm_source=getprice

These are generally used in back up to alarm systems,I was thinking of wiring 3 in series,which should give me 252w 36v

Will these have enough to power this Bafang 8Fun Electric Bicycle Bike eBike Mid Drive Conversion Kit 36v 250w BBS01B
on a GT hybid (13.5 kilo/30lb) bike with 26 x 1.75 road tyres ?

Edit Battery weighs 2 kilo/4.5 lbs x 3 = 6 Kilo/13.5 lbs

 

[Gregory]

These are generally used in back up to alarm systems,I was thinking of wiring 3 in series,which should give me 252w 36v

Correction, it gives 252Wh (Watt hours).
Of which about 150Wh would be usable.

They are heavy, need to be recharged immediately and will die too soon. Probably not proper traction/deep cycle batteries, alarm systems pull virtually no current, you want to draw maybe 10-15Amps.

I'd save my money for something better.

 

[999zip999]

Yobbo are interested in having a usable ebike we are here to help. Buy a cheap kit 36-48 and wr have you hooked. Oh these batteries are free and can hold a full charge I would say 8 Miles a bit of a pain really

 

[999zip999]

Do you already have a motor bike kit to use.

 

[yobbo]

Thanks for the info guys

I can indeed get them free, all hold a charge. But I know where you are coming from

Yes I was thinking about putting 1 in my little Kymco scooter.


Thanks again for replying

p.s Gregory I am also in Perth

 

[Gregory]

Welcome to ES.

 

[amberwolf]

Will these have enough to power this Bafang 8Fun Electric Bicycle Bike eBike Mid Drive Conversion Kit 36v 250w BBS01B
on a GT hybid (13.5 kilo/30lb) bike with 26 x 1.75 road tyres ?

While they may work, you may not get much range from them, or a very long life, especially if they are already used. As noted by Gregory, you'll probably only get a bit more than half of the rated capacity; possibly a lot less depending on their age and what they've been thru already.

I highly recommend charging them at every opportunity, and keeping them fully charged between uses; if they are allowed to stay discharged they can be damaged by it, losing capacity and capability each time. And don't charge them too fast, or the heat will damage them by outgassing electrolyte that can't be replaced in SLAs.

If you look up my DayGlo Avenger thread, there should be info there on when I used 3 similar SLA batteries on it (duct taped to the frame, IIRC :lol to power a friction drive made from radiator fan motors and roller skate wheels. It did work....

I also used larger ones (18Ah I think) for CrazyBike2 for some time, running a powerchair motor thru my pedal drivetrain to the wheel; again it worked...but had nowhere near the range I do now with a similar capacity lithium pack (either of two different kinds), and weighed much much more.