Battery packs

[m11 (Mel)]

Hi All,

Just wondering if other people have problems with batteries lasting in the cold weather. I am using sca car jumpstarter battery pack 1200amp and it drops quickly in the cold as when its warmer weather.

Would having a larger battery or a deep cycle battery be better for colder conditions?

Thanks,

Mel

[raymo]

Jump starters are not really suitable, as they usually have only a small
capacity, not being designed for continuous use. I have used small car
batteries for nearly 40 years without any problems. No doubt other people
will advise you to use other options.
raymo

[m11 (Mel)]

Hi Raymo,

Thanks for that. I think i need to bite the bullet and get something decent rather than a junp starter battery.

Is there any particular battery or brand you would recommend?

Thanks,

Mel

Originally Posted by raymo

Jump starters are not really suitable, as they usually have only a small
capacity, not being designed for continuous use. I have used small car
batteries for nearly 40 years without any problems. No doubt other people
will advise you to use other options.
raymo

[raymo]

Being a tightwad, I go to my local auto electrician, pick up a battery that still
has some life in it for $10-15, and I generally find that it will power my
HEQ5 and a dew heater for a couple of imaging sessions between charges
for 2-3 yrs before giving up the ghost. My last battery spent 6yrs in my
Corolla, and then 3 more powering my scope; cheap power.
If you are powering several power hungry devices, any new small car
battery for about $95 will be cost effective. O.K. deep cycle batteries
are a bit better, but would have to last many years to be competitive
cost wise.
raymo

[m11 (Mel)]

Hi Raymo,

Thanks for that. Good info to know.

Batteries get pretty expensive.

Was wondering do you insulate the batteries in any way for winter or it doesnt matter?

Thanks,

Mel

Originally Posted by raymo

Being a tightwad, I go to my local auto electrician, pick up a battery that still
has some life in it for $10-15, and I generally find that it will power my
HEQ5 and a dew heater for a couple of imaging sessions between charges
for 2-3 yrs before giving up the ghost. My last battery spent 6yrs in my
Corolla, and then 3 more powering my scope; cheap power.
If you are powering several power hungry devices, any new small car
battery for about $95 will be cost effective. O.K. deep cycle batteries
are a bit better, but would have to last many years to be competitive
cost wise.
raymo

[that_guy (Tony)]

I can see the appeal of reusing old batteries and using heavier duty batteries like deep cycle batteries, but I've also seen people use jump packs they got from SCA and Jaycar for years and not have problems. I think the trick is to keep it constantly charged even when not in use and they'll last a very long time. If I had the skill set (and patients), id make a battery box and all that jazz but alas I am too lazy.

[m11 (Mel)]

Thanks for the info.

I have 4 sca jump packs from 900amp to 1900amp. I have noticed the newer ones with the led display dont seem to go as long. Worried as the battery doesnt seem to be stable, especially in the cold, the battery starts beeping and indicator drops by half.


Curious as to what do other people use aswell

Originally Posted by that_guy

I can see the appeal of reusing old batteries and using heavier duty batteries like deep cycle batteries, but I've also seen people use jump packs they got from SCA and Jaycar for years and not have problems. I think the trick is to keep it constantly charged even when not in use and they'll last a very long time. If I had the skill set (and patients), id make a battery box and all that jazz but alas I am too lazy.

[Nebulous (Chris)]

I guess it depends on what you're trying to drive but, like Raymo, I have found that old car batteries can do fine.

I'm only powering a Star Discovery mount but it seems pretty flexible. In that case, the default power is 12v from a small caddy in the body of the mount which holds 8x1.5v AA batteries. (The big trap would be trying to use rechargeable AA batteries which, despite looking exactly like the regular AAs, are actually only rated at 1.2 each. so 8x1.2 is only 9.6v , and 10 won't fit in the caddy).

I bought a lead at Jaycar to get the right end to plug in, and the young guy there tried to tell me that I needed to buy a more expensive setup that regulated the voltage. However, being also reluctant to lash out unnecessary cash I stuck with the basic $5 one!

Just out of interest, I put the multimeter across a caddy of 8 new Duracell batteries when I first got the mount and they showed over 13 volts. They were still working at under 11v. So it seems that the motors will work at quite a range. I guess they just get slower.

I also checked with Skywatcher Australia tech dept and they confirmed that the power brick that I have left over from an old modem will work fine too (it has the correct positive centre tip, 12v, and enough amperage) and that setup works fine too.

As that_guy said, it's worth keeping your batteries on trickle maintenance charge, but my guess is that you can probably use a pretty wide range of batteries and that fancy expensive ones may not be strictly necessary. I have a couple of old ones that have been pensioned off from car duties and that still hold good charge so I could swap over if that was ever required.

Good luck with it all.

Cheers,

Chris

[m11 (Mel)]

Hi Chris,

Appreciate the time and effort to share your knowledge and experience.

Its been a steep learning curve for me personally getting into astronomy. I have never been good with electrics and this is a totally unknown for me, hence the multiple jumpstart packs

I will look at car batteries as i never thought about using them to power a scope. I assume i needed a particular type.

Thanks again to all for sharing

Regards,

Mel

Originally Posted by Nebulous

I guess it depends on what you're trying to drive but, like Raymo, I have found that old car batteries can do fine.

I'm only powering a Star Discovery mount but it seems pretty flexible. In that case, the default power is 12v from a small caddy in the body of the mount which holds 8x1.5v AA batteries. (The big trap would be trying to use rechargeable AA batteries which, despite looking exactly like the regular AAs, are actually only rated at 1.2 each. so 8x1.2 is only 9.6v , and 10 won't fit in the caddy).

I bought a lead at Jaycar to get the right end to plug in, and the young guy there tried to tell me that I needed to buy a more expensive setup that regulated the voltage. However, being also reluctant to lash out unnecessary cash I stuck with the basic $5 one!

Just out of interest, I put the multimeter across a caddy of 8 new Duracell batteries when I first got the mount and they showed over 13 volts. They were still working at under 11v. So it seems that the motors will work at quite a range. I guess they just get slower.

I also checked with Skywatcher Australia tech dept and they confirmed that the power brick that I have left over from an old modem will work fine too (it has the correct positive centre tip, 12v, and enough amperage) and that setup works fine too.

As that_guy said, it's worth keeping your batteries on trickle maintenance charge, but my guess is that you can probably use a pretty wide range of batteries and that fancy expensive ones may not be strictly necessary. I have a couple of old ones that have been pensioned off from car duties and that still hold good charge so I could swap over if that was ever required.

Good luck with it all.

Cheers,

Chris

[raymo]

final word on the subject from me. Jump starters are o.k. for powering
small mounts such as EQ2 or 3, but are pretty useless for powering
medium to large mounts such as HEQ5 or NEQ6 or larger. An HEQ5 used
for viewing involving a lot of slewing can flatten a fully charged 900amp
jump starter in a couple of hours, as it has typically only around
7amp/hr capacity. You can get a bit more amp/hourage with a heavier duty
jump starter, but what is the point when for just a few dollars more you can get a small car battery that will power your rig for about 5 or 6 times as long.
raymo

[m11 (Mel)]

Hi Raymo,

Thanks for that. It will save me money as I have been only getting jumpstarters which only takes me so far.

I think i need to upgrade my batteries. Appreciate all your responses.

Thanks,

Mel

Originally Posted by raymo

final word on the subject from me. Jump starters are o.k. for powering
small mounts such as EQ2 or 3, but are pretty useless for powering
medium to large mounts such as HEQ5 or NEQ6 or larger. An HEQ5 used
for viewing involving a lot of slewing can flatten a fully charged 900amp
jump starter in a couple of hours, as it has typically only around
7amp/hr capacity. You can get a bit more amp/hourage with a heavier duty
jump starter, but what is the point when for just a few dollars more you can get a small car battery that will power your rig for about 5 or 6 times as long.
raymo

[cadman342001 (Andy)]

I have a big 4x4 battery that was replaced as it doesn't hold it's charge

http://www.supercheapauto.com.au/Pro...nuFrom=1021632

would this be ok I wonder

Andy

[raymo]

The battery in your link would certainly do the job, but it would be overkill
unless you would be running several power hungry devices such as
multiple dew heaters, laptops, etc: At 21.9kg it is quite possibly as heavy
or heavier than your rig. Any small car battery from Repco or Auto1
for example will do do the job admirably.
The 4x4 battery you have would do the job if you are happy to charge it
more often than you normally would.
raymo

[cadman342001 (Andy)]

Thanks Raymo, glad it wasn't really your last word on the subject :p

I would certainly like to run the laptop off it as well and it would be good to be able to run it for a few days out bush (we use NP camp sites a lot of the time so no power on site).

Might make a box on wheels for it or run it from the back of the Patrol. Actually, I saw one of those trolleys they use in offices for $19.99 at Office World, could be just the job.

(Just checked the voltage with multi meter after charging, 13.75V. I have unplugged it now and will check it after 24 hours to see how much charge it is losing.)

Which brings me onto another question - what inverter needed for the laptop ? I see lots of discussion re batteries but not inverters.

Sorry for the thread hijack Mel, I'll start a new one of my own for the inverter Q

Andy

[m11 (Mel)]

Hey Andy,

I don't mind at all. Glad that this thread is also helpful to others as well and everyone is so helpful.

I always keep learning and this time showed me I am using the wrong type of equipment.

Feel free to hijack away

Regards,

Mel

[cadman342001 (Andy)]

Mel, everything is new and everyone seems to have an opinion don't they ?

[m11 (Mel)]

Hi Andy,

Yep, you are absolutely correct. I have only taken up astronomy seriously in the last year and half and its been constant learning in between family, work, weather and everyday life

Its good to see what others think and do and work out how to do certain things. I have found everyone really helpful and alot of stuff I wouldn't know what to do without everyones help. No one in my household has the same interest and I found the forums a great resource. I am usually by myself at night as who in their right mind goes out when its 3 degrees in the middle of winter at night to look at stars. Hehe hard to explain and justify to people , let alone the wife

I have found the journey enjoyable and frustrating at the same time. It is made all worthwhile when you see whats out there .

Sorry for the long post and going off topic.

Thanks,

Mel