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).
Comparison of P & R RRN.11 and Exide 3 RRS-12L 6-volt unit batteries.
| Identifier | ExFiles\Box 168b\3\ img021 | |
| Date | 2nd September 1929 | |
| COPY. X7535 J.D. 24. 2.9.29. COMPARISON OF P & R RRN.11 AND EXIDE 3 RRS-12L 6-VOLT UNIT BATTERIES. Two 6-volt unit batteries have been obtained for examination and comparison purposes. These are as at present supplied for S.S. 40/50 HP. production chassis. The Exide has only one cell which is unsealed and two vacant compartments. The P & R has one cell sealed, one cell unsealed and finished off, and one vacant compartment. The following is a detailed comparison of the various items :- MOULDED COMPARTMENTS. best quality ebonite Each unit is a one piece moulded container of Ebonite (with three compartments) with separate lids of the same material, these being fixed by two thumb screws. 1.125" is allowed for sediment space. The moulded units of both batteries are manufactured by one firm and therefore identical. PLATES Exide Positives No. of plates 5 Active surface per plate 5.125" x 4.690" Whole surface including feet 5.75" x 5.095" Depth of feet .187" Thickness .170" P & R Positives No. of plates 5 Active surface per plate 5.250" x 4.560" Whole surface including feet 5.81" x 4.97" Depth of feet .125" Thickness .140" Exide negatives. No. of plates 6 Active and whole surface same as positives. Thickness - two outer plates .100" other plates .130" | ||