Errr...to avoid confusion, it is rated @ 100A (1000mAh = 1A, therefore 100,000mAh = 100A)
Mick64..... a bit dearer 'intial outlay', but longer life and more 'robust' imo, is for a dual battery car set-up, except the second battery is a gel-cell long-life. You just have to get into the habit of switching between the two for their own specific use. The primary battery is only for engine cranking/start-up & vehicle use.
The back-up gets continual charge when not in use, and comes into play once you park up for detecting/camping/partying etc....
I also had a three stage isolator, so when i turned in for the night, i could put both batteries into a stasis state by isolating both.
Worked for me for years in my old cruiser...barely any maintenance, just pull up, switch isolator, plug in device and go.
That way, you don't have to have the keys in the ignition for 'Acc' operation through the ciggy ( a fused direct lead wired from the gel cell rather than through the Acc fused line) outlet. Means you can be charging in the 'locked' car and detecting at the same time.
Gypsy