Em3ev cell_man battery advice

[Frog]

Hello ES I try and not make threads I've been saving for my first build and reading the forums whenever I can. Anyways I check the Em3ev website everyday looking for a 48v15ah A123 Battery Pack or something close. The only 48v ever in stock is the 48v20ah I don't have enough money for the 48v20ah yet.
Should I keep saving until spring to try and come up with the money or ask them to make me a 48v15ah. I don't want to pay more for a custom pack or inconvenience anyone. My commute is small I'm only building the bike for fun riding every now and then I might need to travel about 25 miles with hills. My order was going to be 500w DD kit, freewheel and battery only CA in future if you feel that this is not enough to get the bike going please let me know
Sorry if I put this in the wrong place!

 

[arkmundi]

Those packs are made with the AMP20 cell, a 20ah cell, so you only get a 20ah. Effectively, however, it will be lower. Its a great pack, from a reputable source.

 

[veloman]

He has the Panasonic cell packs which are much more affordable. They may not put out 200amps, but they are fine for the typical ebiker. I believe they are rated at 5c max.

 

[dogman dan]

http://em3ev.com/store/index.php?route=product/product&path=35&product_id=134

This one would do 25 miles at about 20-25 mph. 30 quite possible if you keep it below 20 mph. Or a similar capacity 36v battery of about 20 ah.

If you need to for the cost, get one of the slightly smaller ones, and then ride slow on the days you really must make 25 miles. At 15 mph, you'd make it. On a weekend ride, slow down, enjoy the view, and take your time. 12 ah would be plenty to ride full throttle on the weekdays.

If the triangle battery would fit your bike, the bag and the triangle battery would be ideal.

 

[Frog]

Thank you all. I've been avoiding the Panasonic cell because I have no idea of cycle life is it even close to the A123 cells. I'm going to ride often I don't know how long it's going to be before I can buy another battery. sorry for being asking such dumb stuff

 

[footloose]

Hi Frog--
EM3evsells a charger that has option of charging battery to 90% capacity, which should extend cycle life.
If you took the battery dogman pointed out, and charged it to 90%... You'd be pretty much spot on for the 15ah you were targeting, and get good lifespan for the battery.

 

[Frog]

I'll keep saving for my 48v A123 battery. The Samsung Pack says Cycle Life estimated at 500 cycles plus that's not going to work well for me
Seems like it's never going to end I've been saving for well over a year. Thanks ES

 

[chas58]

You may want a LiFePo4 battery if you are worried about life (i.e. PING battery).
(like noted the A123 single cells are 20AH, so nothing smaller is available.)

Email EM3 and ask Paul what you are looking for. He will give you good advice.

Note that some automotive companies limit charge to 85% and limit discharge to 35%. Outside that range they deteriorate quicker. These have an 8 year warranty. You can simulate this by charging the battery to 90% (using EM3 charger) and not using the last 30% of the battery.

The nice thing about Li-Ion compared to A123 or LiFePo4 is that they are lighter and more powerful (higher voltage that is). You need more LiFePo4 or A123 cells (in series) to get the same voltage.