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).
Tests of sustained Potential Difference (PD) on a battery at various rates of charge and temperatures.
| Identifier | ExFiles\Box 168b\3\ img193 | |
| Date | 16th May 1929 | |
| E.{Mr Elliott - Chief Engineer} & C. J.D.S. Re Tests of Sustained PD on a Battery at various Rates of Charge with fixed temperature. A P&R BDH11-2 6 volt unit battery was partly submerged in a tank filled with water for the purpose of warming up the battery & also to enable its temperature to keep steady. The water was heated up by the use of electric immersion heaters & kept in circulation by a small fan. When the battery had attained a certain & even temperature in all three cells it was charged at various rates from 12 amps downwards & the maximum sustained PD observed & plotted on a graph (attached). This was repeated at several temperatures. Between 50°F & 113°F it will be seen that there is a drop of approx .5 volt. | ||