On 11/03/2015 19:17, Another John wrote:
Thanks a lot for the replies so far!

I hope the battery's not dead! When I tried to take it out last year
(when I first started this job) it would NOT come out of the mower body,
following the manual's instructions. I may have to take the mower apart
to get the battery out.

I will have another go at charging next time I'm across. And No Dave,
I didn't charge it last thing last autumn, mainly because (having
successfully charged it when I took this job on last year) it always
started first time thereafter (it takes about 90 minutes to cut the
grass).

Your least worst option now is to charge it for a couple of hours with a
dumb as a rock simple lead acid battery charger to see if you can get
any charge to stick (ie. enough to start the mower). If it won't hold
charge for at least a week you are stuck with replacing it.

Ideally an initial charge rate of C/10 to C/5 but keep an eye on it.

Smart chargers will sense battery parameters and do a safety cutout if
the battery has gone high impedance or has one cell reverse polarised.
The lifetime of the SLA has been compromised - possibly to zero.

--
Regards,
Martin Brown