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).
Battery test chart comparing the voltage of R&R cells to Exide cells during discharge.
| Identifier | ExFiles\Box 54\1\ Scan185 | |
| Date | 29th June 1925 | |
| 154 S1 Battery 102 lbs 80 a.h. The voltage of the R&R cells were much lower than the Exide cells whilst standing discharged. Average amperes = 6.35 Hours = 9.25 Ampere hours = 58.8 576. 1.80v REGd. TRADE MARK "MEGGER" | ||