Adding battery capacity

[mobetta]

I get about 12-14 miles on my recently assembled ebike kit. The battery is 36v, 10ah and I'm wondering if there isn't a cheap and dirty way to piggy back a smaller battery pack to the unit to get another couple of miles. I know, why not pedal more. Well, I'm 72 years old and getting too old for a brute force approach.

Do I need to match the existing LiFePo4 battery specs exactly, or can I throw together a home brew LiFePo4 36v mini battery pack and plug it into the charging port on the existing battery?

Or should I connect it at the battery output wires?

Will that mess with the existing circuit board's over and under charge protection?

Will the mini pack need its own circuit board and charger?

Sure, I could get a 15ah pack for $3-400, but I'd rather employ a little ingenuity, spend $50 and use the money saved on booze and wimmin.

 

[trex]

there is no easy solution to your problem. If you get only 12 miles from your 10AH pack, then you ride at very high speed or your battery is on its way out. Either way, you will need a new battery because repairing battery without tools and spares is nigh impossible.

 

[anotherkiwi]

I have been toying with the idea of seeing how far I can go on my 10 Ah battery without pedalling (or applying force when pedalling), now I have a challenge - further than 22 km. Will report back later.

65 to 100 km with pedalling so far.

 

[mobetta]

there is no easy solution to your problem. If you get only 12 miles from your 10AH pack, then you ride at very high speed or your battery is on its way out. Either way, you will need a new battery because repairing battery without tools and spares is nigh impossible.

I ride at about 1/2 throttle, but am new to ebikes and don't have all the energy saving techniques down. I can probably get this up to 15 miles. The battery and motor are new. There are sites on the Internet that show how to make your own battery packs at considerable savings.

 

[trex]

They only try to sell you something. I don't recommend you make you own battery. Repairing a ready made one is difficult enough. To make one, you need battery casing, PVC shrink tube, kafton tape, spot welding machine, load tester etc. and obviously battery cells and BMS. Only cwah builds his own batteries as far as I know.

 

[Nealh]

They only try to sell you something. I don't recommend you make you own battery. Repairing a ready made one is difficult enough. To make one, you need battery casing, PVC shrink tube, kafton tape, spot welding machine, load tester etc. and obviously battery cells and BMS. Only cwah builds his own batteries as far as I know.

And he's as mad as the Mad Hatter at Alice's tea party.

 

[mike killay]

My solution is two entirely separate batteries. When the first expires, just plug the second one in.
I do the same sort of thing on my electric boat.

 

[acm2000]

i get 30 miles on my krieger 15ah battery before it hits half way on the battery meter then i usually charge it