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).
Discharged batteries on Bentley chassis, investigating issues with the dynamo and regulator.
| Identifier | ExFiles\Box 58\4\ Scan202 | |
| Date | 1st January 1935 | |
| x61091 Wor.{Arthur Wormald - General Works Manager} From Hs{Lord Ernest Hives - Chair}/Wst. c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Wst.7/MA.1.1.35. DISCHARGED BATTERIES ON BENTLEY CHASSIS. Regarding C's request for a dynamo giving an earlier "cutting-in" speed, we are not convinced that on the Bentley chassis the late "cutting-in" speed of the existing dynamo has been the cause of some of the batteries becoming discharged. We are of the opinion that the prime cause has been the failure of the regulator to respond to low battery voltages due to the volt drop between the battery and the regulator increasing as the charging current increased. The fitting of the new type B2CJI regulator which compensates for this effect should overcome the trouble. Lp.{Mr Lappin} and Bn.{W.O. Bentley / Mr Barrington} both have had these new regulators on their Bentley chassis and Lp.{Mr Lappin} has reported that with full load (which includes 60 watt headlamp bulbs) the dynamo satisfactorily balances the discharge current and no trouble has been experienced with the battery. The Bentley type of customer rarely runs on top gear for any length of time below 20 M.P.H. at which speed the dynamo more than balances the ignition, petrol pump and side lamp discharge and if he drops into gear the battery receives a substantial charge. We are of the opinion therefore that until we have definitely proved that there are customers who still complain of discharged batteries with the new regulator (excepting customers with radio sets) we should hesitate to fit the new dynamo having an earlier cutting in speed (see Wor.{Arthur Wormald - General Works Manager}3/R.14.12.34.). The performance of the new machine at high speeds with headlamp load etc., is worse than standard and if much high speed work is indulged in with heavy electrical load excessive brush wear will result and a possibility of the commutator solder melting. | ||