There are battery chargers and there are battery chargers!!! The old fashioned trickle charger is not good for Caterham batteries unless monitored constantly. The problem is that in “boost” or “ trickle “ charge setting, the charging voltage and current remain constant. So it you forget about it, it will ruin your battery. It is however good at charging completely flat batteries. what you need is a constant potential charger. This is fully automatic and can be left on 24/7. With this type of charger, as the voltage in the battery rises, so the current reduces. When the battery charger voltage and battery voltage are the same, then current ceases to flow. I.e. it’s switched on, but it is not charging. If the battery discharges, the battery charger will automatically start charging again, till the battery is charged. I have an Accumate and it’s been in the same battery for 8 years. There are a number of other quality chargers and it’s worth paying for a good one. Most have the facility for quick connection. Piers