Less simple answer...
The above advice is very generalised. Not all chargers or
batteries are the same. In an ideal world you would need a maintenance charger
that holds your batteries at the perfect voltage for long term storage.
Some mobility chargers do just this! But they don't tell you
that they are doing so. So only a voltmeter and some skill will let you really
know. Some just charge until "done" and stop completely. Again only a Volt meter
can tell you what is actually happening.
The correct storage voltage (Float voltage) the case of a
typical Gel battery would be approx 13.5 Volts per battery (so 27.00v for a
Or in the case of an AGM battery which are becoming more
popular in mobility devices then 13.25v (26.5v) is best for long term storage.
low power maintenance chargers are available from various places. If you value
your batteries these are a better bet than charging it every coupe of weeks with
your mobility charger and will make your expensive batteries last longer in
Also remember that even when turned "off" your powerchair or
scooter will be taking "some" small amount of power from the batteries as that
computer under the seat is still live. The extra drain on the battery means that
the batteries will discharge faster if they are left connected.
So if you are going on holiday or leaving the chair for more
than a couple of weeks, then its best to fully charge overnight as usual and
then disconnect the batteries completely from the powerchair or scooter.
Don't forget to re connect and charge them as soon as you return!
Having said all of this batteries deteriorate in other ways
too. One way is internal corrosion that happens over time. This happens anyway
even if the batteries are kept charged up. So long term storage is better in a
cool place rather than a warm house. This slows deterioration.
In an ideal world you would fully charge them, store them
disconnected from your wheelchair or scooter in the fridge and use a dedicated
float or maintenance charger 24 hours a day. Although this is a bit
So just keep them charged!