remember that the Sigelei 150 runs two batteries in parallel and not series so 20 amps is still the max continuous drain limit off of them. This isn't something to worry about too much as the chipset inside the mod regulates power draw as part of it's safety features but if you really want to push your wattage above 100 watts I would get a pair or two of VTC 3's or VTC 4's for sure. It's not a huge deal but drawing that kind of current off of the 25R's, even in a regulated setting, constantly can shorten their operational lifespan.
Not a big deal, just something to be aware off...it's good to know if your dual battery mod operates in a "series" or "parallel" battery configuration...both have their pro's and cons but right now most of your main high wattage box mods like the IPV3 and Segelei 150 are series style mods.
The simple version of the difference between the two is that a parallel setup splits the load evenly between two batteries so you still only have 4.2 volts maximum output like with a single battery...however, because two batteries are sharing the load evenly you will have double the max continuous drain limit and double the run time than if you used a single battery. For example if I used two VTC 4 batteries in parallel my max output voltage would still only be 4.2 volts like a single battery, but because I am using two of them my run time for the mod is now 4200 mah instead of 2100 mah and my max continuous drain limit has been increased to 60 amps instead of 30 because the batteries are sharing the work evenly.
In a series configuration the batteries are "stacked" on top of each other and the power of one is combined with the other to double the output voltage. So instead of 4.2 being the max volts you have a max voltage output of 8.4 volts but your mah would still be 2100 like a single battery and your max continuous drain would still only be 30 amps like a single battery. The pro of stacking batteries in a series configuration like this is that with a much higher voltage output you have a much lower amp drain on your batteries.
Most of the common high watt dual battery boxes like the sig 150 and the IPV 3 use the series setup and what's called a "step down" converter in their chipsets so you can have that high wattage so many crave now days without a huge amp drain.
That's the short, not simple, but short version of it...I am sure it left you with some questions and please ask...I'd rather give too much information than too little...information is safety and safety is happy vaping