Honda model HRR2169VLA not charging battery

[Chathamite]

This is what I bought from Amazon:

• Neptune NT-1213 12 Volt 1.3 Amp Sealed Lead Acid Hi-Capacity Rechargeable Battery

I just noticed is not in stock now. It was $14.95 at the time of purchase. Mowed today and it started every time I turned the key (about 4-5 times stopping and starting). Don't know how long it will last but it was an experiment.