Jump starter amps

[pat]

Thinking of getting a 12 volt jump starter for my Celestron 120mm slt. The one starter I see shows about 120AH. Is there any effect on the moter with higher amps. I believe I've read that only 17AH is needed for this scope. Thanks, Pat

[haitch]

They might be different figures. One is probably the peak amps it can provide and the other (the lower) will be the amount of energy it can store in terms of amps of power for an hour (or number of hours at 1 amp) that is the measurement for the 17Ah. Neither of those is a problem as the mount will draw what it wants - you just have to makes sure it can provide enough for as long as you need it to. Volts are more of an issue for equipment.

[Avocette]

AH means amp-hours which is capacity not current. So if your drive uses 3 amps for 4 hours you will consume 12AH. The Jump Starter at 120AH has more than five times the capacity (duration) of the Skywatcher 17AH one or over 17 times the capacity of the Skywatcher 7AH one.

[faulksy]

if your correct and its 120 a/hr that will way around 30+ kgs. as said 17 a/hr will be ok but if your sessions last a while it might not last plus if you add optic heaters it will lasteven less, also consider ambient temperature this will drain your power tank even more.

[pat]

Thanks, I believe what was said is that volts are more important. The more amps, the longer the motor will run. Pat

[haitch]

Thanks, I believe what was said is that volts are more important. The more amps, the longer the motor will run. Pat

Yep. You can have issues where you can't get enough current to run your gear but that tends to be more of a problem with mains adaptors as some of the cheap ones can only push an amp or 2. Jump starter batteries are designed to give a big kick of amps (i.e. to turn a starter motor) so delivering enough shouldn't be an issue. The main problem with jump starters is the impact on their life by being repeatedly charged and discharged when they were designed to be kept charged and used for the occasional high current delivery. I've a Maplin 17Ah jumper that the battery died in after a year. I switched it out for an alarm battery of the same dimensions but about double the weight and that seems to run a lot better. The best type of batteries for running astro gear are leisure batteries as there purpose is more akin to the use you'll be putting them to.

HTH

[Wolfgangwand]

As has been said , a leisure battery is the way to go regarding cycle discharge - recharge although there is no such thing as a leisure battery really if you speak to manufacturers ( quality of materials used / design ). If cost is not an obstacle lithium is a superb product and will be the choose of many once cost comes down and storage capacity increases.

[Wolfgangwand]

Sorry about the grammar , can't edit

[haitch]

I'm waiting for hydrogen fuel cells to hit the shelves!

[Wolfgangwand]

Not sure how to put a link up but google " Lithium 4 Golf " . The 24Ah cell is £100 cheaper than advertised at IAS.

The weight of this cell is 25% of a 17Ah lead acid alarm battery or similar with very good discharge curve / final drop out.

[gkec]

Not sure how to put a link up but google " Lithium 4 Golf " . The 24Ah cell is £100 cheaper than advertised at IAS.

The weight of this cell is 25% of a 17Ah lead acid alarm battery or similar with very good discharge curve / final drop out.

Is this what you mean

http://www.puredrivebatteries.co.uk/shop/details.php?prodId=194&category=5&gclid=CIaTjp7qr7cCFdDJtAodqU0A1Q

(Just paste the link)

Interesting but expensive.

[Wolfgangwand]

https://www.google.co.uk/url?sa=t&rct=j&q=lithium4golf&source=web&cd=1&ved=0CDgQFjAA&url=http%3A%2F%2Fwww.lithium4golf.com%2F&ei=HvCfUdz6K-qm0QWBioDYDw&usg=AFQjCNFUPKXZR-AxEOrkCAVa6bCIDO4mFA&bvm=bv.47008514,d.d2k

Hope this works !

[Wolfgangwand]

Thanks gkeg !

[Wolfgangwand]

[removed word] !! Sorry , gekec

[Wolfgangwand]

Never mind - thanks anyway .

[gkec]

https://www.google.c....47008514,d.d2k

Hope this works !

Yes it worked.

I am sure some people will find the light weight really useful. However there is still the cost factor compared to £50 from Mapln. Very interesting.

[Wolfgangwand]

gkec , apologies for getting your name wrong on previous posts , large fingers / small iPad /getting frustrated syndrome. ( not yet sure how to edit posts )

[Cornelius Varley]

gkec , apologies for getting your name wrong on previous posts , large fingers / small iPad /getting frustrated syndrome. ( not yet sure how to edit posts )

You need 250 posts before you can edit your own posts. In the meantime if you need a post editing contact one of the mods (red names) and we may do it for you.

[haitch]

Yes it worked.

I am sure some people will find the light weight really useful. However there is still the cost factor compared to £50 from Mapln. Very interesting.

Yep, I tend to think golfer are even more easily parted from their money than astronomers... He says having bought three ED refractors and two 82^o eyepieces in the last couple of months

[bomberbaz]

Yes it worked.

I am sure some people will find the light weight really useful. However there is still the cost factor compared to £50 from Mapln. Very interesting.

ten years warranty make this an item everyone will soon be buying. My tank is ok as yet but once it starts flagging, I think I shall be getting one of those bad boys.

[gkec]

gkec , apologies for getting your name wrong on previous posts , large fingers / small iPad /getting frustrated syndrome. ( not yet sure how to edit posts )

Don't worry about it. I knew what you meant. I find it frustrating not to edit posts. I think I may be nearly at the required post count. Not that I'm posting to up my post count. Oh no.