Electrical scooter having an equalization circuit for charging multiple batteries
US5965996A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1997 |
| Grant date | Oct 12, 1999 |
| Priority date | — |
| Expiry date | Dec 11, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/70
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric scooter employs an equalization circuit for charging a plurality of series connected batteries used to power the scooter. The equalization circuit has a number of cell circuits, each connected across the terminals of a corresponding battery. Each cell circuit includes two voltage detectors, a first implemented as a modular voltage monitor for detecting a low voltage across the battery terminals, and the second implemented as a Zener diode to detect a high voltage across the battery terminals. Both voltage monitors are enabled by an optocoupler switch. When the switch is turned on and either a low or a high voltage condition is detected, the cell circuit outputs a signal reflective of this condition through a second optocoupler. During a constant current charging phase, a high voltage condition causes the cell circuit to cause a portion of the charging current to bypass that battery, thus achieving equalization. A controller, which selectively enables the first optocoupler, also receives outputs from logic circuitry which tells whether any of batteries have low voltage and also whether the series connected batteries are fully charged. The scooter monitors the batteries f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.