SLA (sealed lead acid) batteries can be gel or AGM - which is just the type of electrolyte technology they use - Optima uses their "Spiralcell" AGM technology which of course just changes the lead plate layout - and has a very good reputation.

The 1000 amp "peak rating" is a made-up number that has no industry standard associated with it - just like the "peak watts" output rating of cheap audio receivers and amplifiers that was supposedly eliminated years ago - but somehow have shown up again.

The jumper may give you a 300 CA (cranking amps) for less than 30 seconds, but enough to get you started.

actually he gave me 2. one has a built in 300 watt 120v inverter. makes me wonder what folks do with these things after batteries slowly fail? they cost $60-80 new and replacement batteries are the same price. people buy them for 1 or 2 uses and 5 yrs later, they don't work.

I was looking for inverter and just happened to find it. Found a new jumper on CL with a 400 watt inverter for $30. Says it has 12ah battery. A bit smaller than my units which have 18ah batteries.

got my new battery

Where did you buy the battery from? I am asking because I need a new battery for my computers back-up battery unit (UPS)
I need a 12V 8.5AH I looked at the big box type stores and they only have up to 7AH and they want about $45 for one of those

Oh I forgot to ask how are those battery jumpers wired inside?
I have one that has a 12V Cigar lighter and a USB port (5VDC), and an LED work-light
I am just curious as the one I have also has reverse polarity protection and a switch so you don't connect the cables "Hot" I guess to avoid sparks Thanks

YOu can buy AGM batteries all over the web. Check locally too. Shipping is possible with AGM as opposed to flooded cel, but the weight still kills you.

take off case cover and eye wiring scheme. pretty easy. yes, online was 30 and in store was 75. online sites pay employees. same as local stores. does that explain 2x price difference?

Circuitbreaker-
Call around to local alarm companies, especially those that deal with fire alarms.
These are common batteries for fire alarms- the 12V 7Ah, the 12v 8Ah, and also the 12V 18Ah battery.
May find an alarm company close by that will sell you a battery.

Auto parts places like auto zone and oreillys sell these as some lan mowers and motorcycles use them.