From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Proposing a simple battery charge indicator using a green light to warn the driver.
| Identifier | WestWitteringFiles\Q\April1927-June1927\ 28 | |
| Date | 22th April 1927 | |
| TO EFC. FROM E.{Mr Elliott - Chief Engineer} C.c. to BJ. BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} ORIGINAL E2/M22.4.27. re. BATTERY CHARGE INDICATOR. V4040 In response to your enquiry concerning the above, the idea is simply to use a device for switching on a green light as soon as the battery voltage reaches a pre-determined quantity. This will warn the driver to put his ignition switch in the 'no charge' position. Naturally this device will be in the nature of a voltage measuring instrument, but as it can only affect the charging installation through the agency and observation of the driver, its duty is less onerous, and any trouble in connection with it would be more manifest than with the completely automatic scheme. MADE AT CROXLEY E.{Mr Elliott - Chief Engineer} [Signature] | ||