Issue withSky Watcher Tank

[hayju01]

Hi,

I seem to have an issue with my Sky Watcher Powertank, well 2 issues actually.

1. The 'Fully Charged' led doesnt come on anymore, at least not unless I take it off charge (once i know it must have been on long enough) and then immediately put it back on charge. So the LED is working.

2. I only got 2.5 hours out of it tonight and it was just running my NEQ6 mount nothing else.

Anyone else has similar issues?

Thanks,

Justin

[Bizibilder]

Which powerpack is it? - one is 17Ah and the other only 7Ah I believe.

[hayju01]

It's the 7Ah one.

[Bizibilder]

I don't have one but I have read posts that say the tank needs a full 24hours (or more) to fully charge and that the light often does not come on even when charged. Your mount will draw around 1A when tracking and 2A when in fast slew so 2.5 hours may well be enough to drop the voltage so that it is unable to drive the mount.

I hope this is not too depressing!!

btw you can get a 17Ah jump starter from Maplins for £19.99 (its usually on offer at that price) which will charge and run your mount for 5-6 hours - that IS depressing!! Sorry. (Those SW powertanks are really overpriced!)

[hayju01]

Thanks Bizi (I think )

19.99 WOW! that really does show over priced these SW's are!!!

I'll try leaving it on longer and see what happens, have emailed FLO anyways to see what they say.

I hate the noise mount makes when it can't get enough juice hope its not busted the gears

More annoyed that this is the first clear night in 5 and I've had call it a night already!!!

Must stay away from Sales Section.....must not circum to temptation...must go to bed......

Oh well one quick look to see what's there can't hurt......

[Bizibilder]

Ah!! The "noise" you mention - this may be the problem! It is possible that one (or more!) of the gears in the mount has become loose on its shaft and is simply spinning "free" OR that a couple of gears are not meshing properly. Do you have the clutches tight? This may also lead to "no drive".

Before you bin the lot in disgust it might be worth checking (or have checked if still under warranty). 'Tis a bit of a pain but you may find this cures the problem.

PS Buy a decent sized power pack anyway - you'll need it in the winter when batteries struggle in the cold!

[hayju01]

Oh no! I feel my world coming to an end :-(

The noise only occurs when the powertank is running low e.g. the mount has started to flash its led at me. I usally spot this but sometimes as last night I was too busy gazing.

I've had a response from FLO suggesting that the tank just needs a 'proper' charge, it went on at midnight so I'll see what its like when i get home this evening.

I hear you but how do I smuggle even more kit into the house I'm getting suspicious looks as it is :-)

[Photosbykev]

take the battery out of the car and use that for the evening, it will easily handle a night of observing and still start the car . or a set of jump leads from the car would also work

[hayju01]

Not a bad idea Kev.

Infact that could be the answer to my Obs dilema. put the scope in the car and open the sunroof when observing....simples :-)

[Starlight 1]

Not a bad idea Kev.

Infact that could be the answer to my Obs dilema. put the scope in the car and open the sunroof when observing....simples :-)

I think you got it but a campervan will be better as you have a bed

[Bizibilder]

That's what Astronomy is all about........Smuggling!!!!

[hayju01]

Its her birthday Sunday and at this rate she'll be very disappointed when she doesnt hundreds of presents as thats been the 'excuse' for the last month ;-)

[LDUNN1]

The issue with many of these portable power packs is that the chargers for them are only rated at 500mA, so it takes days (literally) to charge a flat 17Ah unit back up to full charge.

For my nEQ6 I found a local company online that sells nothing but batteries & chargers (I'm new on SGL so don't know the rules about posting links to companies - to I'll avoid mentioning the company by name for now) & bought two small sealed 10Ah batteries & a charger that is rated to charge up to 5A, so in about 4-5hrs I can re-charge my batteries ready for the next night. I can also use the charger for my car battery too (it also does motorbike batteries & 'leisure' batteries up to 90Ah).

Why did I go for two 10Ah batteries instead of one 20Ah? Well, I have a plan to make up a craddle for these two 10Ah batteries & the craddle will slide onto my counter balance shaft in place of the dead weight - will lighten the kit I'm dragging round to dark sites. Plus the power cable will run along the shaft up to the head & as the two are fixed relative to each other it will avoid the power cable getting tangled / snagging / pulling out. I'll have one battery either side of the counter balance shaft, & the batteries I went for can be used in any position except for continuously inverted (unlikely on an EQ mount).

Beware that there are differnet battery technologies out there - car batteries for example are designed to give a large dollop of power in a short burst of time.......totally the reverse of what our mounts need - continuous small sips of power for hours.

'Leisure' batteries (made for non engine start electrics on campers, motor caravans, boats & the like) are designed to deliver lower rates of power over longer time periods, & are more suited to our motorised mounts.

Most car batteries & 'Leisure' batteries are much bigger, heavier & have way higher amp-hour ratings (70-120 Ah is typical) than we typically require - hence why I went for the two smaller 10Ah units.

If anyone wants to know the name of the company I used near Southampton, PM me.

[Daniel-K]

Ah!! The "noise" you mention - this may be the problem! It is possible that one (or more!) of the gears in the mount has become loose on its shaft and is simply spinning "free" OR that a couple of gears are not meshing properly. Do you have the clutches tight? This may also lead to "no drive".

Before you bin the lot in disgust it might be worth checking (or have checked if still under warranty). 'Tis a bit of a pain but you may find this cures the problem.

PS Buy a decent sized power pack anyway - you'll need it in the winter when batteries struggle in the cold!

i had this problem NO DRIVE it was down to the gears its a simply fix

[hayju01]

What's the fix melibum?

The only thing i cant figure is why do I only get the noise when the powertank is low, suggests to me that its just that tank thats at fault not the gears.

did i miss something?

[LDUNN1]

I've heard others comment on the terrible noise the SW EQ's make when they run out of battery juice.......I have not heard it myself yet, but it is meant to sound real bad........& goes away when fresh power is restored apparently.

[hayju01]

yes, that would tie in with my experience. Its not as if the Eq is quite at the best times but this noise is very disturbing

[LDUNN1]

......I'd also been keen on hearing what this easy 'fix' is.......just in case the noise ever happens to me - although I've had teh red light flashing several times & I've even had the power totally go so scope would not even slew, & still no noise......maybe SW fixed something - mines an nEQ6......

[hayju01]

mines an NEQ6 too and less than two months old?? strange that you've not had it, think I'll give FLO a ring in the morning (if they answer) can't have two bits of kit not functioning correctly in under 2 months.

[Photohound]

Back on the powertank for a sec.... i read a previous post somewhere on here after experiencing my powertank not showing the fully charged light - the bottom line seems to be that they need very regular charging, ie: at least 24hours once a week and... straight on charge after using. if you let em drain down to the flashing light it can take 3-4days (i actually left mine on for a whole week 24/7 once) before full charge is restored.

[hayju01]

WOW! thanks for that. I have had mine on since I started this thread until around 10 tonight so whats that 46hours give or take. Using right now and all's ok so far. Will put on charge when i finish tonight but it sounds like I need to leave it on for a day or two or 7!

Thanks,

Justin

[hayju01]

FLO are arranging collection of my faulty powertank, I messed up as my email said I'd purchased it in 2010 when in reality it was April 2011. Of course this will probably mean I will be without ANY power for at least one night until the replacement arrives :-(

[Skylook123]

Many snippits of good avice here. Please allow me to add some more color to the sketch.

The type of batteries called Jump Start is the kind we astronomers "jump" at. In fact, this type of battery is what Celestron, Orion, et al., install in their Power Tanks. The problems with this use are many. Some have been raised here. They include:

1. They want to provide a lot of power in a short burst; we need long, low use.

2. They need to be recharged immediately after the burst, since the chemistry inside the battery will start damaging the plates; we tend to use them long, wait 'til later to recharge. Kills them far too soon.

3. The so called "wall warts" for charging them are totally inadequate. They provide too little current to accomplish the job in a reasonable time, they have no protection against going too long and damaging the battery, the often fail in only a few months but don't give any sign, and when they fail they can fail "hot" and really damage the batter.

The only possible pluses of these units is that they come in a carry container, and they have astronomy logos on the outside so then make us think they are OK.

Now, some of us make these work by tender, careful care. Too many of us, however, end up quite disappointed.

Here is a path taken by many of us who have been fooled about these units.

1. Find a Deep Discharge or Marine use battery (fishing boats, wheel chairs, golf carts, other scooters). These are designed for the type of use we impose: slow drain, infrequent recharge. They tend to have more capacity than the standard 7, 12, and 17 AH astronomy kit and 18 AH automotive emergency jumper battery. I personally use a 35 AH Deep Discharge battery with my Atlas.

2. Purchase a quality multi-state charger/conditioner and use it in place of the wall warts. These have the ability to detect sulfation on the plates and actually recondition the battery. Multi-state means an initial maximum current until the voltage comes up to spec, then lower rate while the capacity builds, finally holding a zero current level that does not damage the battery, allowing it to be permanently on the charge. Soneil, a Canadian company, makes the units sold under their name and the Battery Defender names. There are other good ones out there.

To use a charger/conditioner with the Jump Start battery, just run the output of the charger straight into the jumper cable clamps, being sure to turn on the capability on the Jump Start. Most have a switch to turn on the jumper cables, but the Orion/Celestron units do not; the cables are always "hot".

To match the convenience of a jump start unit, I put my Werker 35 AH battery into a case that has a fused output to either +/- poles, or a built in cigarette lighter socket. The battery is internal to the case, so all I need to do to recharge is to connect the output of my Battery Defender/Soneil 1206 charger to the +/- posts on the carrier case. There are many, many amateurs who have designed and built their own cases from coolers.

In short, deep discharge/marine battery, quality charger, recharge as soon as possible to keep the battery healthy.

I hope this helps explain the magic of these power supplies.

[LDUNN1]

Skylook - totally agree with you!!! Pretty much said the same in my posts too. It is the best way forward - costs a bit more initially, but you have lots of pluses & only inconvneinece in the lack of the nice carry case & all the bells & whistles built in that the power tanks manufacturers seem to love adding to make their goods seem more attractive without addressing the fundamentals......

Good post.

[Photohound]

@skylook123

some good points there jim.

just to clarify the position with my kit if i may...

i have the skywatcher powertank, if i use one of these...

OptiMate 4 Battery Optimiser

(which i have for my motorcycle battery) would i connect it straight to the red/black posts or use an adaptor throught the little 'charging port'.