Cheers man, this is all becoming a lot clearer.
More questions.....(I ask a lot dont I?)
"I think you should get something that isn't designed to die, like the eGo or kGo with their sealed batteries."
Is the SB also something that isint designed to die?
Why the sealed batteries?
I think id prefer the unsealed ones because their probably cheaper to buy and a SB looks a lot stronger than an eGo.
IOW
whats IOW stand for?
No battery lasts forever. As they age, they will need to be recharged more frequently. If you use a device that uses generic, replaceable batteries, you simply replace the batteries. You can buy an 18650 battery for as little as $5-6 here. A top of the line 18650 costs about $8-12. At that price, you can replace them when they have even a relatively small decrease in performance. The e-Power and the Silver Bullet are two models that accept generic lithium batteries.
A kGo or eGo or Riva IS the battery. They are a battery sealed in a housing with a switch and connector. When they begin to decline in performance, or when they die, you must replace the entire PV. They cost from ~$15-20 each. The manufacturer specifies an average expected lifespan of 4-6 months. They are disposable and "designed to die", similar to a disposable flashlight as compared to a flashlight that uses common replaceable batteries.
Another thing to consider, is that batteries have an expected lifespan expressed in terms of charge/drain/recharge cycles or "duty cycles". An eGo battery is sized from 650-1000mah. A loose 18650 lithium battery can be up to 3100mah. The more mah, the longer the battery lasts between charges. If a 1000mah battery and a 3000mah battery are both rated for 500 cycles, the 3000mah battery will last 3X as long as the 1000mah battery because it will only need to be recharged 1/3 as often. The discrepancy is even greater in real life because you can easily get an 18650 sized battery that is far better quality than any ego battery and it will be rated for more "duty cycles". Where the 1000mah ego may need to be replaced in 6 months, the 3100mah lithium can be going for 2 years.
At $20 for the eGo and $12 for the 18650, the yearly operating cost is $40 vs. $6.
Is the SB designed to die? The SB has a "vandal proof" switch that's used in commercial applications like ATM machines and public intercom systems. It is rated for 1,000,000 mechanical cycles and 250,000 electrical cycles. It is modified to last longer than 250,000 electrical cycles. Nobody knows exactly how much longer, but I have estimated that I probably have around 350,000 on the same switch in my BB. With tube mods like the SB and Roughstack, the switch is probably the most important single thing to consider and the SB is top of the line. Only a full mechanical switch like on the Innovaper model could be more reliable, but you'll still need to change out springs on a mechanical switch. The SB is definitely not "designed to die". In fact, you can hardly kill it if you try.
And yes, the SB is stronger than an eGo by orders of magnitude. You can't run over an eGo with a truck. You can't drop an eGo into the Gulf of Mexico and expect it to ever work again. You can't pound tent stakes into the ground with an eGo. Well, you could, maybe, but that's the last thing you'll ever do with it.
IOW = In other words...