Power tank for HEQ5 problem

[bendiddley]

OK I have a 7ah powertank and I'm trying to run a black HEQ5 (non go to) from it. It's just to power the tracking, nothing else. I charged it a couple of months ago and tested it when it had charged and it was working fine, but took it out last night and it wasn't working very well. I can only hear the HEQ5 motors tracking when I press the direction buttons on the handset, when it's just running normally, the sound is very faint if non existent at times. There seems to be some tracking but it is much slower. Should I charge it before I use it? Also what's peoples thoughts on this powertank, is it suitable for an HEQ5 or should I get something more powerful, if so can anyone recommend anything?

[alan potts]

I am led to believe that these power tanks are meant to be charged up all the time, there is a sticky on powertanks on site somewhere. I allowed mine to die in the cold a year ago and that was the end of it, it never worked again. I imagine batteries by their very nature do lose charge slowly no matter what the temperature but cold will not help them for sure.

I have a replacement cell in my 17AH unit now and it is not the same as the old one, over all I can't say I have been very happy with it, I prefer the mains unit I have as I was getting many tracking and slewing faults, Site helped me with that problem which was the lead to the scope in the end, but it took a bit of finding.

Alan

[bendiddley]

I am led to believe that these power tanks are meant to be charged up all the time, there is a sticky on powertanks on site somewhere. I allowed mine to die in the cold a year ago and that was the end of it, it never worked again. I imagine batteries by their very nature do lose charge slowly no matter what the temperature but cold will not help them for sure.

I have a replacement cell in my 17AH unit now and it is not the same as the old one, over all I can't say I have been very happy with it, I prefer the mains unit I have as I was getting many tracking and slewing faults, Site helped me with that problem which was the lead to the scope in the end, but it took a bit of finding.

Alan

Thanks Alan. What mains solution did you come up with? Also you mention replacing the lead, I was also wondering if my lead was to blame, what solution did you get for this?

[Mikea]

What charger do you use for charging? Also, if you have a voltmeter, check the voltage while on charge, then again about an hour after finishing the charge. Charging voltage should be 13.5 to 14V (might be as high as 15V if battery is very flat), fully charged battery should be 12.6V. I use a CTek charger.

[ronin]

The batteries used are the problem. They basically drain and then are useless. Suspect they resemble the motor cycle ones and I used to find that if not used then after 6 to 8 weeks I had problems. I lost count of the number of batteries I went through.

What people do is get a deep cycle battery, although check that it really is a deep cycle. The term seems to be applied to ones that are not. Deep cycle one's also require a slightly different charger.

Not sure if one of these would be applicable:

ebay-battery-Li-ion

I have a 6800 one and getting it to 12.6 volts takes time, and mounts seem to dislike low power (volts). Although mine appear happy at a bit less then 12v, but mine are Meades not Skywatcher's.

There are the Tracer batteries that are good, also cost a fair bit higher as well.

[Owmuchonomy]

Several comments:

I had a black HEQ5 and a Powertank when I first started out.  The PT was next to useless.  At most I got 40 minutes out of it. So I purchased one of these which is excellent. http://m.rapidonline.com/Catalogue/Module/77155

Secondly, you won't hear the motors in normal tracking mode; I certainly couldn't.  When you are slewing around in anything more than Sidereal speed then you will hear them.

[Staffs Oatcake]

I was looking at getting the 7Ah power tank. But having read such back things about them.. ...... I started to wonder So I went down the route of finding a 12v regulated supply or a car battery. I wandered into my local Hafords and came across their Phaze 4-1 jump starter pack at £39. Got to worth a punt I thought. Even if it doesn't power my goto Synscan upgraded EQ5 mount I can keep it handy for when the car won't start. Well equipped with two 12v outlets it performed admirably. Equipped with a 17Ah battery. It's goes on and on and on. It quite clearly states that it must be charged at least every two months.

[Feral Rabbit]

I have a 7Ah PowerTank, that is permanently on charge and to be fair it hasn't let me down. I've used it for 5 hours maximum but it never ran out of power running my AVX mount. I'm not sure how well it's going to fair with a dew heater too so I have another (car jump start) battery pack ready for when I get the chance, and the weather allows me to get out.

I think I'm right in saying that these PowerTanks have Lead Acid batteries in them and once they become deeply discharged they tend to become damaged, just like the battery's in car/motorcycle and are difficult, although not impossible to salvage.

The up side is that they are cheaper than leisure battery's but obviously they do have their downside.

Regards
 

[xtreemchaos]

i have the 7ah skywatcher powertank on my HEQ5 and it works well, but saying that ive only run the mount off it,no dew heaters ect , ive had about 8 hours inbetween charges, and it was nowhere near flat when i put it on charge.  charl

[bendiddley]

What charger do you use for charging? Also, if you have a voltmeter, check the voltage while on charge, then again about an hour after finishing the charge. Charging voltage should be 13.5 to 14V (might be as high as 15V if battery is very flat), fully charged battery should be 12.6V. I use a CTek charger.

Just the standard charger that came with the PT. I don't have a voltmeter unfortunately.

[bendiddley]

Several comments:

I had a black HEQ5 and a Powertank when I first started out.  The PT was next to useless.  At most I got 40 minutes out of it. So I purchased one of these which is excellent. http://m.rapidonline.com/Catalogue/Module/77155

Secondly, you won't hear the motors in normal tracking mode; I certainly couldn't.  When you are slewing around in anything more than Sidereal speed then you will hear them.

Re hearing motors, you can if you put your ear to the mount.

[bendiddley]

I was looking at getting the 7Ah power tank. But having read such back things about them.. ...... I started to wonder So I went down the route of finding a 12v regulated supply or a car battery. I wandered into my local Hafords and came across their Phaze 4-1 jump starter pack at £39. Got to worth a punt I thought. Even if it doesn't power my goto Synscan upgraded EQ5 mount I can keep it handy for when the car won't start. Well equipped with two 12v outlets it performed admirably. Equipped with a 17Ah battery. It's goes on and on and on. It quite clearly states that it must be charged at least every two months.

Thanks, I might look into this.

[bendiddley]

Thanks all for your comments and advise!

[bendiddley]

Ok I think I might have found the cause of the problem. I forgot to mention that I use an adjustable voltage power cable to connect the power tank to the mount and I've just checked the voltage it's currently set to and its 6 volts. Am I right in thinking that the heq5 mount should be 12 volts? If so then I can change this and hopefully get it working.

[Cornelius Varley]

Ok I think I might have found the cause of the problem. I forgot to mention that I use an adjustable voltage power cable to connect the power tank to the mount and I've just checked the voltage it's currently set to and its 6 volts. Am I right in thinking that the heq5 mount should be 12 volts? If so then I can change this and hopefully get it working.

The HEQ5 does require 12v.

[bendiddley]

Great thanks. Also does anyone know how long a power tank should be charged for?

[triton1]

Overnight should do it 8hrs?

[Staffs Oatcake]

Does it not have a charge light o tell when it's fully charged?

[bendiddley]

Yeah it does. I just wondered how long as I've only charged it once and can't remember how long it took last time

[Mikea]

I'm not sure I trust the electronics in the power tank to indicate charge status correctly. Mine always says it needs charging, even when I have charged it directly (via the terminals) using a CTek charger.

[Waldemar]

charging time depends on two things: capacity of the battery in Ah and the charging current. If you want to charge a 10 Ah (Ampere/hour) battery it will take 5 hours to charge it with 2 A current. so, easy arithmatic. But... the further it is charged, the lower the charging current will drop. That is depending on the charger as well as the battery quality.

The more charging cycles the battery had, the longer it takes to get it fully recharged. Deep discharging kills the battery... very low teperatures too. Best way to prevent low temperature problems is to put the battery in an styrofoam isolated box. 

Drop charging works best for every battery, also it can stay attached to the charger, which will keep the battery in good condition. The charger is more expensive though,  because it is electronically regulated. 

An indicator if a battery is fully charged is a volt measurement. A fully charged 12 V lead battery measures  ± 13,6 Volts without a load. If a cell died ± 2 volts will be missing and the battery will be of no use anymore for longer then a few minutes, depending on it's capacity and the drain.

regards,

Waldemar 

[metalman]

On ‎12‎/‎01‎/‎2016 at 08:54, Mikea said:

I'm not sure I trust the electronics in the power tank to indicate charge status correctly. Mine always says it needs charging, even when I have charged it directly (via the terminals) using a CTek charger.

Neither would I. I think the LED light system on my 2011 SW 17aH PP was causing me to undercharge the battery on numerous occasions...leading to deep discharge and early retirement.

I did come across a sticky thread somewhere on the net (maybe on this site) that advised caution using the indicator lights. And advised charging until the red light goes out (or something like that).

Once I did that it was a little better.

In the end I replaced it with a leisure battery which I am very happy with, although still needs monitoring of the battery voltage to ensure it is not discharged to much.

Steve