Why is my EQ6 blinking?

[perfrej]

Skylook!

You sum it up very well, indeed. Let me just add that apart from Lithium, the best "mobility" option out there is the AGM battery. At twice the price to the sealed gel batteries, and at ten times the usefulness, these batteries are totally top of the line.

AGM (Absorbant Glass Mat) stores the electrolyte in glass fibre mats between the plates and they can take a beating like no other - total discharge is usually not a problem at all.

Another good point in favor of the AGM is the ability to take charge. A standard lead acid battery is usually said to be able to take 20% of the rating in charge current. So, at 30 Ah, a lead acid will take 6 A of charge current no matter how much you have available. For AGM, that figure is a good 50%, more than twice that of the lead acid.

I have dual AGM batteries in my car (from factory, the only approved batteries) and will, if my Lithium experiments do not turn out well, fill my case with about 25-30 Ah of AGM at next opportunity.

As for chargers, I couldn't agree more. In Europe, the CTEK line of chargers fill the role, are available in different sizes and do handle AGM as well as gel and straight lead acid.

Maybe I should make a case and sell it less batteries? It would have power outlets ay different voltages and built in USB HUB for all your goodies on the mount

/p

[Merlin66]

Skylook,

Excellent overview and summary!

Mods: this should be a "sticky" in the equipment section - the topic gets revisited every few days......

[Merlin66]

Perfrej,

Well if you don't start making the cases, I'm sure someone will come along...it's too good an opportunity to miss...

[jonathan]

That AGM thing and the Mobility batts certainly sound the business, I will be looking into this further but it definitely would be something I think the less handy with woodwork among us may be willing to pay somebody to make.

Less than $110 you say? I think that will probably be a case of $ = £ sadly, but it could be worth it.

[Skylook123]

There is SUCH a need for a battery box with the RIGHT battery techology. All things electrical are such magic to me (thus my turning a Celestron Power Tank, and another Jump Start kit, into door stops) that I jumped at the box I linked to above; all it took was drop the batter into it, and screw the cables to the poles.

Jump start batteries can work; it is just they are being used outside their intended realm with our low power/long duration need, that they really do need to be maintained and operated carefully. I really wish they would rate them as "Useable" capacity, given that the chemistry changes during use mean that only about 50% of the full rating is really available. If I were king...

[jonathan]

Just one quick question... am I right in thinking that the basics are that two clips to the battery terminals could be wired straight to the power socket on the mount, no regulators or anything else in between?

I would probably not do it exactly like this, there would be a nice power port on the battery box etc, but is that the theory with these AGM batts?

I strongly suspect that my Maplins power tank is now a door stop too... time to live and learn!

[Skylook123]

That AGM thing and the Mobility batts certainly sound the business, I will be looking into this further but it definitely would be something I think the less handy with woodwork among us may be willing to pay somebody to make.

Less than $110 you say? I think that will probably be a case of $ = £ sadly, but it could be worth it.

Well, my destruction of two perfectly useful kits totalled about $175 of cash dropped into a trash bin, so, as a long term investment, it makes up for the waste over time. Some lessons are painfully expensive. And since I use my Atlas many times each month for public events, and the mount does not have mechanical controls, it is very frustrating for the red light to start blinking after only an hour of just tracking due to a trashed battery.

Still, it is curious that with the explosion of high priced technical assets for our hobby, this is a simple product that would seem to beg a manufacturer to start cranking out. Economy of scale and all!

[jonathan]

Just looking on Amazon it seems that mobility scooter batteries are very widely available, and in many different sizes / capacities.

Something like this, perhaps: http://www.amazon.co.uk/Mobility-Scooter-Battery-AGM-12v-42Ah/dp/B002USO2MW/ref=sr_1_11?ie=UTF8&qid=1317572895&sr=8-11

15kg sounds heavy though...

Found the same battery box available in the UK: http://www.pushtheboatout.com/acatalog/info_MD189980.html

Almost twice the price once converted to £££, but that is typical really. I'm going to look for gel battery suppliers, as from numerous websites it seems these should be better than AGM batteries for astro use, although they may cost more.

Assuming I use an NEQ6 with two dew heater tapes on an Astrozap dew heater controller, does anyone know what my total typical current draw would be? What size AGM battery would be recommended, assuming I might wish to get six hours out of it at a time between charges (in case I forget one day)?

[jonathan]

The Maplins power tank has a 17Ah sealed lead-acid battery, if I could find a gel battery that fitted would it just be a case of fitting it? I would probably have to sort out a proper charger which could connect to the built-in charging socket, would that work? I have seen a 12Ah gel battery, should be good for several hour's use with all of my kit running.

It would save me constructing a new case, and I should be able to use the sockets and USB charging ports too. I like the big handle on it too, makes it easy to carry. I could possibly add a red torch or something like that. I think the LED battery indicator on this kind of device is probably worthless, it has never shown anything less than full for me despite the battery obviously not performing at full power. If anybody could suggest a better power meter, perhaps a charge / discharge amps meter from an old car would be a good addition.

This is what my Maplins power tank looks like:

While I have it apart I might be tempted to paint it a different colour, any suggestions? Perhaps white to match the NEQ6.