# Increasing range on my bike



## PierreR (May 17, 2012)

Hi all, I hate the dreaded battery range anxiety on long rides. I have two new batteries coming to add to my bike. I will need to figure out where to mount them and a parallel wiring system that does not look like sht. When I am done I will have 2,560 watt hours of battery capacity on my fat bike. That should be enough for long bikepacking rides without frequent charging options. 
Also need to add new handle bars because the current bars do not have enough real estate. I am thinking Jone's bars with a nice custom instrument cluster/light switch panel in the oval center. I have some burled walnut and polycarbonate for the face of the instrument cluster. 

I bought a 52 volt 15 amp charger to go along with the big battery setup. I should have the batteries later this week but the charger will take a long time to get here.

This is all going to take some serious thought and I will post progress as I go along. I am not in a rush. I would rather do this one time, have it right and at a minimum weight gain. 

Anyone else going the route of increasing range on a parallel battery setup?


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## blcman (Feb 1, 2007)

I don't know if a "parallel" setup is really necessary. Why not just move the batteries to the original mount as they gets low. You are still carrying them with you, right? It would be a lot less wiring which could add complexity and problems IMHO.


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## Whiterabbitt (May 16, 2020)

No. But good for you, 2.5 kWh is nuts.

I planned on back country ride capability and wanted more current draw for such rides since biking wasn’t the point of such a ride (thus turbo 100%...). I simply bought an extra high cap battery and hauled it along in my pack. 20 miles out with 6000 ft elevation gain, overweight, and enough to get back and make an extra trip if needed.

but that in total is less than half of the capacity you are looking at. My only concern would be the weight you carry will make the motor less efficient so it is decreasing gains. But not sure how much battery you’ll be hauling. Ball parking 700 Wh at 8 lb, you’ll carry an extra 20lb or so of battery which makes a 50lb bike a 70lb bike, which makes assist a real drag. Maybe no biggie if you have a throttle? Anyway, just thinking out loud. My strategy was totally different.


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## matt4x4 (Dec 21, 2013)

0.10V difference for paralleling, otherwise the surge is to much.


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## PierreR (May 17, 2012)

matt4x4 said:


> 0.10V difference for paralleling, otherwise the surge is to much.


I have two batteries in parallel now. Try as I did to always make sure they were close to the same voltage, I did finally make a mistake at about 1.5 volt difference. I paralleled them for up to a minute before I realized what I had done. No big sparks, fried terminals and huge noticeable surges. I suspect the 30 amp BMS saved the day however the surge did not seem as high as 30 amps.
After realizing it I disconnected the higher voltage battery and charged them separate. No sense pushing my luck at that point. Might have decreased life on the batteries a bit but I have not noticed any damage.


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