Charging golf trolley battery whilst in car

Depends what you mean by decent. Normal run of the mill vans just use a split charge arrangement, which only results in slow charging. Think about it. To recharge a 100Ah battery at a safe rate that tapers down to the 90% point takes about 12 hours. You aren't going to drive for 12 hours are you? What happens in practice is that the aux batteries charge up while you're on the move, but once you're parked and you have mains the charge rate is far higher. After a two hour run it's almost as if the batteries haven't been charged on the move at all. High end vans run an inverter all the time they're travelling, so if necessary the mains chargers run from that.

Bill

Is a golf trolley battery an SLA? If so maximum charge voltage is 13.8v Depending on age, a car alternator can be as high as 14.4v.

The model he quoted is LG-A150 which is AGM SLA, the spec sheet says

Cycle Use: Initial Charging less than 6.0A, Voltage 14.4V~15.0V

Standby Use: Initial Charging No limit, Voltage 13.5V~13.8V

AGM is advanced gas mat. Basically, a wet battery. A true SLA uses gel. Do wish they'd stop mixing up names. ;-)