Thanks for that Phil.
I quick but limited search that I ran did seem to indicate that there were some similarities and they were of the same family or type, although the gel cell models tended to be more expensive than the SLA models.
Anyhow, mine are (Jaycar) SLA’s and I also have a (Jaycar) SLA charger, so provided I charge them monthly, I trust I’m not going to blow up the garage!
Cheers
Dennis