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).
Estimating battery temperatures and open-circuit voltages under various conditions.
| Identifier | ExFiles\Box 168b\3\ img194 | |
| Date | 16th May 1929 guessed | |
| II J.D.S. I estimate that a temperature of 110°F could be attained in the battery on the car whilst running on a normal warm day & this would be exceeded in a hot summer's day. It may be noted that the maximum permissible temperature is 100-110°F.{Mr Friese} This estimate could be tried in a practical way on a car when convenient. The open circuit volts at a temperature of 50°F were 6.43 volts & at a temperature of 110°F were 6.45 volts. This after standing for 15 hours. J.J. | ||