BTW: Welcome to CPF (the icon won't past for some reason).
Thanks its does, but some im An ultra noob. Its very hard for me to learn all of this new stuff in enough time to make the right purchase, ya know? So Hmm.. I need a power supply and a charger.
If weight and cost are secondary to turnkey, and ease of use (no soldering, no wiring up a PCM), then go the designed for bike prebuilt battery pack route.
I get protected packs? Why do I need a pair of these ( see above ) and something from this page? ( see above again ) It does suck and I Do need my hand held during this battery pruchase. Id like to do it right the first time, and have what I need exactly to full understand it all.
Well, you may consider the suggestion a litmus test of your knowledge/skill level. If you went the Hobby battery route, you would need the matching plug for the battery output so you could run a connecting cable to the light. Your answer tells me, as does this response that you should not go that route.
The Hobby packs are designed to deliver very high currents so have no short, excess drainage, or max current protection. As bike batteries may be subject to mishaps, and the batteries are often near the rider, a fiery off gassing and near explosive pyrotechnics is undesirable in the extreme. So protected packs are advisable. This is an intermediate or advanced level DIY project.
The more expensive water bottle battery has PCM's for each series. This and the packaging increase the cost. A less expensive charger will do, which is in the package deal.
With the LEDs pulling that much power, I would need a 9600 mA battery.... haha. thats for what, 2 hours? Now I may not be running it full blast at all times. Im hoping I can get what I need around 50% or 65-75% brightness...
We don't read minds about how you are going to run your lights. So the suggestions are only as good as the info.
First you should know that at 1.5 A you are getting more heat per unit of light, so a lot less runtime for little more light, meaning you need a much bigger battery for 2 hours. You can google for the technical sheet on the XP-G and see that the output versus current chart is a decreasing curve. Many consider 1 or 1.2 A as an acceptable high and save 1.5 turbo mode for occasional downhills. I found that 0.5 amps on two triples would do most of my local riding but I needed 1 A on the highway shoulders to compete with car headlights.
I provided the equations you need to calculate this. That technical sheet has another chart. It is Vf for the XP-G versus current. The Vf x Current = Watts per hour. You have 3 Leds in each light.
So for 1 A current supplied, the XP-G Vf is 3.35 V. So that is 3.35 W per LED, or 10.5 W. The driver will use 2-15%, so we will assume 10%. So each light needs about 11.5 Watts per hour, 23 Watts for a 2 hour runtime each. Using a 7.4 Volt pack means you divide 23 W-hr by 7.4 or 3.1 A-hr, or 3100 mA-hr. If you want a single pack for both lights, twice that. Having two separate packs gives full redundancy. If one battery fails, or you forgot to charge it, you still have light.
You can do the same calculations for 1.2 A or any other level you wish.
Here is a 4.4 A-hr waterproofed pack. You will need the charger linked further down the page and its adaptor for the trailtech plug, You will need at least one male trailtech connector if you are running one power cord to both lights with no other connections. Most of us have a male at each light, maybe a 2 female 1 male Y, and a female to male patch cord if the battery is not near the lights. You should order what you need with the battery because their shipping is expensive. You are free to search for other sources, I provide this only so you can see this sort of setup.
Two of those with chargers and adaptors are the same price as the single water bottler battery with over 10 A-hr capacity.
We will answer questions, discuss pros and cons, but this is a DIY forum, not a HSEDIFM (have someone else do it for me) forum.
Hope you can take if from here.
BrianMc