11-10-2017, 01:23 PM
(11-10-2017, 07:35 AM)Bob Culver Wrote: The advent of Low and No Maintenance batteries has altered much of the following traditional information about batteries.
Life is shortened by long periods undercharged or, worst, flat, by overcharging, and by repeat cycles, especially deep, and by a lot of very slow charging (as distinct from floating). In their day most Sevens suffered the first three and life was often short.
For typical modern use, with little night running, a modest summer charge perhaps interspersed by none and maintained by a modern bench charger would seem near ideal, provided initial charge rate when low is about 4amps min (for 80 ah) and voltage on charge is suited old style batteries, and does not exceed about 6.9 v after initial charge.
Bob, starting a car on 6V with the starter gives the battery a lot of stick, a lot more than on a 12V car (about double would you believe?). So a 6V battery will always last less than a 12V equivalent.
The two cars I have on the road, one will always start 2nd or 3rd pull on the handle, so I'm not using the starter at all. I'll drive it anywhere as I know it will start. The battery will barely spin it over in anycase. But on the move the current given by the dynamo means its ok with the lights on. The other car, a poorer starter, needing considerwable cranking, the battery will put a good effort in of a morning, but I have the issue if I drive it somewhere, and leave it all day, the sod might not have enough go when I come to start it. And it pretty much wont go on the handle. Ive taken to charging it all night. Get up earlier than I want to leave. Get it started, then put it back on charge untill I'm ready to go.