Quote:
Originally Posted by Leo.G
Thanks Bob that's quite an affordable solution for a light weight LiFePo4 battery. Sorry, Lithium battery.
Any idea what sort of run time with a normal EQ skywatcher mount (EQ5 pro, laptop computer and minimal draw camera?
I have some new 8-AH lithium Aldi 20 volt packs I could run through a buck converter to get the required voltages, not sure how long it would drive my gear but I have a couple of new units and it would be worth me looking into, already having the battery packs, I could wire a couple up in parallel in my dedicated battery box I bought new and have never populated.
Plus I could try them in the yard where I have AC power available as a back up. I'd have to fit a 19 volt outlet for the laptop, a 12 volt regulated output for the mount and 5 volt for the camera but it works straight off USB I believe. It's minimal work to set it all up and try it.
|
Sounds you have it all pretty much sorted Leo, , Who'd ever thought of using power tool batteries and the likes with a step down buck converter, your a genius mate,, super light and portable, bit of sorting with connections initially but wow, great going for initiative.
bit of a diverge but I have a lady friend who uses one of them AA, AAA, rechargeable battery stations, funny thing is she has been using the non rechargeable batteries in them, EVEREADY's and cheap $2 shop bulk pack non rechargeable types, never had a problem with em, great for small torches, remotes and older typical household items, I was surprised but there you go, sorry I digress Lol
But yes, quite lightweight is the 20Ah LiFeP04 @ close to 2Kg,, the 8Ah is approx 1/2 the size weighing only 0.95Kg & the 12Ah is only 1.4Kg.
How long would the 20Ah last, well, the Eq5 draw approx 1Ah while tracking and can draw 3-4Ah when slewing but that is only for a few minutes at a time,, but if your slewing a lot then that adds up..
The good thing about Lithium's compared to AGM's is you can access about 85-90% of the batterie capacity, say 20ah in this instance, so you should be confident in running the EQ5 for 15hrs,, But a 20ah AGM can only access 45-50% of its capacity and would only run the same EQ5 mount for closer to 7-8hrs..
Mind you with any battery operating in the cold 'as we astronomers do & speshly in winter' you could easily deduct another 10-20% from the run time
Now adding the Laptop to this battery I would have a stab-in-the-dark, no pun intended, Lol, while using a 12V to 17V inverter supply, I estimate the laptop would draw approx 2 maybe 3Ah, depending on size and power of the processer and how much work it is doing ?
All said, If your Laptop is fully charged before starting your astro session, (By the way - the camera uses very little power, only milliamps, like 0.1 or 0.2 of 1amp, so no worry there) I would have fair confidence this 20Ah would last a night of 5-6 hours