Celestron PowerTank Lithium with HEQ5 Pro

[AdeKing]

5 hours ago, Jiggy 67 said:

Why do you think you can’t use the smaller version?...looking at it on FLO it has the 12V cigarette socket which is all you need 

Reading this thread I think there is some confusion.  If you're referring to this Celestron power tank then it definitely does not have a 12v cigarette lighter socket.

https://www.firstlightoptics.com/batteries-powerpacks/celestron-lithium-lifepo4-powertank.html

It only has a 2.1mm 12v power output.

I have two of the 7.2ah versions and the 2.1mm output is the only output, apart from the USB sockets.

5 hours ago, willcastle said:

The smaller one has the 12v output for the celestron power lead. It doesn’t have the cigarette socket 😕 

That is correct, if you want to use a cigarette lighter cable with the 7.2ah power tank then you'll also need one of these adaptors or an equivalent.

https://www.firstlightoptics.com/astronomy-cables-leads-accessories/lynx-astro-silicone-21mm-dc-jack-to-female-cigarette-socket.html

5 hours ago, Jiggy 67 said:

Sorry, I hate to disagree but it does. On the picture you can see it covered by an orange vertical piece of plastic....same as mine on the larger version 

I have two of the 7.2ah versions and can confirm that the 7.2ah version does not have a cigarette lighter socket, only the larger 13.2ah version has the cigarette lighter socket.

https://www.firstlightoptics.com/batteries-powerpacks/celestron-lithium-lifepo4-powertank-pro.html

I thought that this needed clearing up in case it confuses anyone.

[willcastle]

Yup. Everything AdeKing just said is spot on. And you also taught me something new there: I actually CAN use the celestron power tank (after all that) by using the adaptor cable. Thanks for your contribution  

[happy-kat]

I use the 7ah Celstron lifFePo4 with the Virtuoso mount and the power lasts ages, I used it at least 8 times during the previous winter before I charged it again, I'm usually outside for between 1-2 hours. It came in handy during a power cut as well.

Edit

I see you've made a decision and bought something now.

Edited January 5, 2020 by happy-kat

[willcastle]

6 minutes ago, happy-kat said:

I use the 7ah Celstron lifFePo4 with the Virtuoso mount and the power lasts ages, I used it at least 8 times during the previous winter before I charged it again, I'm usually outside for between 1-2 hours. It came in handy during a power cut as well.

Edit

I see you've made a decision and bought something now.

I think these lithium batteries are the way to go. The jumpstart kit will keep me going for now and I will definitely upgrade to the lithium one when funds permit 

[happy-kat]

I choose it because it had the better environmental foot print both in construction, use and life length, yes more expensive but actually way cheaper in the long run.

[SimM]

On 05/01/2020 at 16:30, willcastle said:

Do you know what the current is for the 12v sockets? I know the HEQ5 needs a minimum of 2amps? But then I’m guessing it isn’t an issue if you had it that long.

This afternoon I placed an order for an HEQ5 Pro Mount. I wanted to get a portable PSU but I didn't think a Power Tank 7 Ah is sufficient or a 17 Ah is cheap enough. So this morning I "invested" in a Halfords 4 in 1 after reading about it here last night - thanks guys!

The spec is quite interesting. It's a plastic case with a sealed lead gel battery (no spills) and has a good capacity/money spent, it's 12V 17 Ah. Inside is an "intelligent" charger and a 5V USB 500 mA supply for phones etc. Externally there is an AC adapter (looks unregulated) 12v charger. I suspect that it's really more than 12V in - otherwise the battery wouldn't easily charge up e.g. read 12.6V.

They also supply a car connector to plug - looks to be the same as a Sky-Watcher cable. Only the PSU brick is labelled - the outputted for the connector isn't speck'ed. I will be checking it but I'm sure the polarity wouldn't be different (otherwise, it would be a problem to plug the cable into the input - a short if it was (incorrectly( reversed). 

The combined load for equipment is limited to 10A although it can supply much more e.g. when connecting to another (flat) battery. 12V 17 Ah, 10 A means it's a 6 cell 12V battery (like in a car) with a good capacity e.g. 17 Ah means 17 x 1 amp or equivalent. the 10A means that it an supply high current e.g. up to 10A for just over an hour and a half.

There are at least four things to note from the manual:

1. The battery won't leak e.g. orientation isn't important

2. don't use it when it's charging e.g. suggests input PSU isn't regulated

3. output is going to start at 12.6V and eventually drop to about 12V (a car battery is the same)

4.  don't let it go flat (the technology isn't like a marine battery - so keep it charged

5. don't expect to start a car using the battery (connect to a 2nd battery and let the power transfer across e.g. wait a short time)

NB points 4 and 5 will cause problems for anyone who doesn't take the time to read the "manual".

Halfords offer a 12 month guarantee and a 28 day money back deal. It seems a good deal - I paid £45 (asked for a discount).

The needs of a HEQ5 Pro are a voltage between 11V and 15V and 2A at high voltage or 4A at lower voltage. NB this is only when "slewing". When "tracking" the supply will be a very small fraction of this to keep the RA in "sidereal" motion and the internals in readiness. 7 Ah batteries are probably more than good enough but 17 Ah is better. I may take a peep inside later...

It has some advantages/disadvantage over a Power Tank:

the PT won't display the voltage status when it's being used

the PT can't supply both 5V and 12V at same time

the PT has red light (better for the eyes and acceptable at a Star party if dim) - I will wait a week, put it through it's paces and only then "mod" it

Simon

Edited January 8, 2020 by SimM
spelling...

[willcastle]

16 minutes ago, SimM said:

This afternoon I placed an order for an HEQ5 Pro Mount. I wanted to get a portable PSU but I didn't think a Power Tank 7 Ah is sufficient or a 17 Ah is cheap enough. So this morning I "invested" in a Halfords 4 in 1 after reading about it here last night - thanks guys!

The spec is quite interesting. It's a plastic case with a sealed lead gel battery (no spills) and has a good capacity/money spent, it's 12V 17 Ah. Inside is an "intelligent" charger and a 5V USB 500 mA supply for phones etc. Externally there is an AC adapter (looks unregulated) 12v charger. I suspect that it's really more than 12V in - otherwise the battery wouldn't easily charge up e.g. read 12.6V.

They also supply a car connector to plug - looks to be the same as a Sky-Watcher cable. Only the PSU brick is labelled - the outputted for the connector isn't speck'ed. I will be checking it but I'm sure the polarity wouldn't be different (otherwise, it would be a problem to plug the cable into the input - a short if it was (incorrectly( reversed). 

The combined load for equipment is limited to 10A although it can supply much more e.g. when connecting to another (flat) battery. 12V 17 Ah, 10 A means it's a 6 cell 12V battery (like in a car) with a good capacity e.g. 17 Ah means 17 x 1 amp or equivalent. the 10A means that it an supply high current e.g. up to 10A for just over an hour and a half.

There are at least four things to note from the manual:

1. The battery won't leak e.g. orientation isn't important

2. don't use it when it's charging e.g. suggests input PSU isn't regulated

3. output is going to start at 12.6V and eventually drop to about 12V (a car battery is the same)

4.  don't let it go flat (the technology isn't like a marine battery - so keep it charged

5. don't expect to start a car using the battery (connect to a 2nd battery and let the power transfer across e.g. wait a short time)

NB points 4 and 5 will cause problems for anyone who doesn't take the time to read the "manual".

Halfords offer a 12 month guarantee and a 28 day money back deal. It seems a good deal - I paid £45 (asked for a discount).

The needs of a HEQ5 Pro are a voltage between 11V and 15V and 2A at high voltage or 4A at lower voltage. NB this is only when "slewing". When "tracking" the supply will be a very small fraction of this to keep the RA in "sidereal" motion and the internals in readiness. 7 Ah batteries are probably more than good enough but 17 Ah is better. I may take a peep inside later...

It has some advantages/disadvantage over a Power Tank:

the PT won't display the voltage status when it's being used

the PT can't supply both 5V and 12V at same time

the PT has red light (better for the eyes and acceptable at a Star party if dim) - I will wait a week, put it through it's paces and only then "mod" it

Simon

Nice detailed assessment of the Halfords 4 in 1. I have fully charged mine. I am just waiting for some clear skies to get going with it. 

One thing I would add to your excellent summary is that the initial charge is definitely around 18 or so hours. It took a loooooong time to charge. But apparently it is vital to give it that full initial, uninterrupted charge. You also shouldn’t use the battery at all prior to the initial charge (or during, as you said above). 

I thought I read in the manual that it said you have to charge it after every single use too.... but I would have to check that. It might have been more relating to if you use it for starting cars?

i want to really take care of this battery though because my last one cost over a hundred pounds and died after minimal usage 😕 

another thing I like about the Halfords charger is that you can press a button to see how much charge is left in the battery. I can’t remember the Sky-Watcher one having that , or maybe it wasn’t quite as good. But it was a few years back so I can’t remember. 

As for the built in red light on the skywatcher model..... you won’t really find you use it much. Especially if you have a head torch 

[SimM]

On 05/01/2020 at 12:36, Physopto said:

It is only about 7Ah. So 12 volts at 2 amps, not really a viable life before it need recharging (3.5 hours).

The HEQ5 requires up to 4A at a low voltage e.g. 11V or up to 2A at a high voltage. That's worst case.

The power used is much higher when doing work e.g. slewing. So I would expect the capacity to last a long time.

It couldn't sustain a continuous high current for too long e.g. for a dew heater set with a high duty cycle.

Simon

[SimM]

On 08/01/2020 at 21:10, willcastle said:

1. initial charge is definitely around 18 or so hours
2. you have to charge it after every single use too...
3. you can press a button to see how much charge is left in the battery. I can’t remember the Sky-Watcher one having that

1. Doesn't the initial charge time depend on when the unit was made and how long it has been self discharging?
2. Transferring energy to a (dead) car battery will flatten it
3. Sky-Watcher doesn't show power when in use

Edited January 10, 2020 by SimM

[SimM]

The battery is 12V 17Ah and the car clips are directly wired to the battery via a switch (see below) - so voltage and current are v. stable/dependable for a scope - hooray!

There are six screws on the back. The battery is replaceable e.g. a Yuasa NP17-12 battery (180mm x 76mm x 167mm) is a drop in replacement, however the cost is £42 (Amazon), so the Halfords unit represents v. good value.

Mod 1:

The case has small slots beside the holes for the battery clips - for a "neater" look the cables can be disconnected and the cable ends passed through the hole/slots (requires a small spanner).

Mod 2:

If the starter cables are disconnected then the switch can be "repurposed" to allow quick isolation of the pair of 12V car ports e.g. Move the black wire from the battery to the other side of the switch.

Simon

Edited January 10, 2020 by SimM

[SimM]

On 08/01/2020 at 21:10, willcastle said:

One thing I would add to your excellent summary is that the initial charge is definitely around 18 or so hours. It took a loooooong time to charge. But apparently it is vital to give it that full initial, uninterrupted charge.

You are right! I noticed that the charger changed from green to red very quickly. After trying it, the recharge time was also ridiculously quick. I had the unit replaced and now it has taken a long time to charge up.

The problem may be with the charging circuit and not the battery so replacement is the only option. One way to ensure a good charge is to not plug the charger in and use a CTEK (or equivalent) “intelligent” charger connected to the clips. BTW, each clip only conducts on one side of the grip. I have one of these chargers already and they are quite sophisticated.

Update

The supplied charger delivers a voltage to the battery to charge it. When the battery is charged the green light changes to a red light. I measured the voltage on the battery e.g. across the red/black clip. When the battery is charged the voltage is about 15.9V with the charger plugged in and switched on. When the charger is switched off or unplugged the voltage immediately drops back to 14.5V and a few minutes later will stabilise at about 13.6V.

This indicates two things. The first is that the battery is fully charged because it should be at least 6 x 2.2 = 13.2V. The second is that the charger (wall unit and internal electronics) does not switch off completely. Although it may potentially limit the current, it still puts a voltage across the battery so it will eventually degrade the battery if left permanently attached. An "intelligent" battery charger will charge a battery and eventually stop charging the battery, it then waits for the battery voltage to drop before trickle charging the battery until it's full. The "intelligent" chargers can be left permantantly attached and the battery will always be close to fully charged. The Halfords charger is not quite so sophisticated so leaving it permanently attached could be a problem.   A good solution is to initially charge the battery for 18 hours as the manual suggests - this quickly (or slowly?) restores the battery to a fully charged state. After the light turns green, a voltage is still applied to the battery so there is benefit leaving it for the full 18 hours. After use, the battery should be recharged and using the supplied charger, disconnected when the light indicates that it's fully charged. Leaving the charger attached and switched on so that the battery voltage is elevated would not be a good idea e.g. it's not 'plug and prey' and is closer to 'plug and manage'. Better charging would be achieved using an 'intelligent' charger e.g. connected to the clips with the external charger unplugged/removed - this type of charger could be permanenty attached.

Forgetting to charge the battery so that the voltage drops below 6 x 2.1V = 12.8 V will sulphate the battery and quickly cause it to fail. Leaving the battery on the supplied charger after it's charged could also potentially limit the useful life. Also, letting the battery fully discharge rather than topping it up after each use will also shorten the life. The chemistry of all lead acid batteries is the same, there are variations e.g. sealed and AGM batteries, but the operation is the same e.g neglect the battery and it will deteriorate. If a battery can be recharged 300x (more with partial recharging) then it is deemed to have achieved it's full working life/capacity.

One potential problem with lead acid batteries is leaving them on a damp concrete floor at low temperatures - this is avoided with the Halfords unit because it's contained in a plastic housing and so is at least insulated from the floor. 

Simon

Edited January 12, 2020 by SimM