Current Status

We are successfully using a single 170w panel and a MPPT boost controller to charge our three 48v e-bike batteries. With this extremely simple set-up, we logged 2500+ miles of solar-powered bike riding from March-July 2020.

It is working well and keeping up with our current needs, but we have some planned upgrades:

  • Intelligent Charging
  • Monitoring
  • Switches/distribution panel
  • Large Cheap 48v (maybe DIY) battery for storage and
    • at home charging while riding
    • DC-DC Charging
    • better storage while touring the Friendmaker

Technical Specifications

  • Sunpower SPR-E-Flex-170 6×8 Solar Panel
    • 170w
    • 24v
    • 6×8 cell
    • Outer dimensions 45.4 x 31.9 x 0.8 in
    • flexible
  • Genasun GVB8-WP MPPT Boost Solar Charge Controller
  • Batteries
    • Two no-name 12.5Ah 48v hailong-style down-tube lithium batteries
    • One UPP 17Ah 48v hailong-style down-tube lithium battery

Voltage Reading

Percent Charged


54.6 V
Nominal max voltage of the battery
54 V
Maximum charge boosted by the Genasun (24v panel, Genasun boosts to 54v)
51.48 V
Max charge for storage
48.36 V
Minimum charge for storage
39 V
39v is cutoff voltage for motor to operate; can still charge cell phones/run computer

Projects, Fixes, and Upgrades

By |2022-05-10T22:28:56+00:00July 24th, 2020|Bikes, Solar Power|

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