Battery options...

[chrisc (Chris)]

Hi everyone,

I've just taken delivery of a shiny new Celestron C8 SCT, and a HEQ-5 Pro mount. I need to buy a portable power supply for it, and while the off-the-shelf Celestron Powertank options seem inviting, I am concerned as to the nature of the battery involved in these products.

The larger (17Ah) version has the words "Car Starter" stenciled on it, and I'm worried that this (and presumably the smaller 7Ah model) are essentially car batteries. That is, designed for shallow discharge and constant topping up from an alternator. Such batteries are ill suited to deep discharge cycling, and a deep-cycle battery such as those found in golf carts and standalone power systems are a much better option.

Does anyone know which of the two type of battery are actually used in the Powertank products??

I e-mailed Celestron, and their best answer was "They're sealed lead-acid batteries", which was impressively unhelpful.

I'm going to wander in to Battery World tomorrow to check out options and pricing for some deep cycle batteries, but would still like to know if the Celestron Powertank is a viable option.

Cheers,
Chris

[Starkler (Geoff)]

Unless the words "deep cycle" are prominently emblazoned on it, assume that it is not because true deep cycle batteries are a LOT more expensive.

I run a number of dew heaters and an argonavis off a 12ah battery and never look like running it down in a night, so a standard 17 for you no worries at all. You could get away with a 7 if you're only running the heq5.

All you need is a cheap power-tank unless you want to start running a laptop then running those power sucking beasts gets more complex.

[mill (Martin)]

Originally Posted by chrisc

Hi everyone,

I've just taken delivery of a shiny new Celestron C8 SCT, and a HEQ-5 Pro mount. I need to buy a portable power supply for it, and while the off-the-shelf Celestron Powertank options seem inviting, I am concerned as to the nature of the battery involved in these products.

The larger (17Ah) version has the words "Car Starter" stenciled on it, and I'm worried that this (and presumably the smaller 7Ah model) are essentially car batteries. That is, designed for shallow discharge and constant topping up from an alternator. Such batteries are ill suited to deep discharge cycling, and a deep-cycle battery such as those found in golf carts and standalone power systems are a much better option.

Does anyone know which of the two type of battery are actually used in the Powertank products??

I e-mailed Celestron, and their best answer was "They're sealed lead-acid batteries", which was impressively unhelpful.

I'm going to wander in to Battery World tomorrow to check out options and pricing for some deep cycle batteries, but would still like to know if the Celestron Powertank is a viable option.

Cheers,
Chris

Hi Chris those 17Ah batteries are sealed lead acid batteries and the same as the celestron.
Buying gel cell batteries is a good choice but they need a gel cell charger.
Martin.

[chrisc (Chris)]

Hi Geoff,

Cheers. The manual that came with the HEQ-5-Pro suggests that it can draw up to 2 amps (presumably when slewing at maximum speed), and while I'm sure the average power consumption will be lower than that, I think I'll still try to err on the conservative side... might be driving the scope around for several hours a night now and then. :-)

Despite my previous post, I haven't explored the local battery store options yet, but am about to head off there in the next hour to see how horribly expensive the deep-cycle options in the 10-20Ah range are.

Cheers,
Chris

[pin3appl3 (Darcy)]

Chris I picked up a Urban Battery pack (30 Ah) from ebay for I think AUS 350 delivered - http://cgi.ebay.com.au/Urban-Basic-3...item4cec998efc
Which works sweet for the HEQ5. It may be a bit out of your price range but I invested with the idea of it being versatile for camping and when I eventually get more equipment (ie laptop etc) for my setup. It has sockets for 12V devices and other accessories included and is made by the same company that makes Thumper batteries. Hope this helps!

Darcy

[bmitchell82 (Brendan)]

i don't want to sound like a buzz kill, but that is a very expensive price for a 30A-h battery, for the same price you should be looking at 80-100A-h.

Like martin said, if your only running the mount off it, then 17ah is fine, its once you start using it for Astrophotography that things get a little tricky.

The EQ6pro will draw upto 2amp hours flat out tugging a 10" + all the frills for AP, but while tracking, it barely kicks over at 500mA

Hope that helps you
Brendan

[OneOfOne (Trevor)]

I initially bought a Celestron Power Tank to drive my C8NGT, which works fine, however, I wanted a second battery and just went down to the local car accessory place and bought a "Jump start" battery, yellow one. I think the yellow is mid range. Much cheaper option, although it only has one cigarrette lighter output, the Celestron has two. The jump start has worked fine for the last 4 or 5 years and is much cheaper.

[dulwich.hill (James)]

I have just bought one of these:

http://cgi.ebay.com.au/ws/eBayISAPI....=STRK:MEWAX:IT ($95)

The golf cart batteries deep cycle and this particular one seems to be a high Ah for a compact size/weight. You need to buy a matching charger though).

James