12v Jump Starter

[bosun21]

I know that quite a few members use these as a power source for their equipment. What I would like to know, is are they any good? and can anyone recommend one that they have found decent. 
PS:-  what type of connection do they use? Many thanks  

    Ian 

[DaveL59]

be worth saying what you hope to drive with it and for how long so folks have an idea of the loading you'd be pulling.

I have a LiPo brick I got off Amazon when they were doing a discount deal and that seems OK. 12v ciggy socket that plugs in using a 2-pin connector that seems fairly standard on these sort of units. Yaber branded. Only thing I noted was it puts out 16v no-load when charged so I use a 12v 5A buck converter in-line to limit the voltage to the EQ5 synscan system for which the manual recommends 15v max. I don't run dew heaters or other stuff off it tho since I don't use those.

Edited October 1, 2022 by DaveL59

[bosun21]

Thanks Dave. I wanted this as a back up and it would be driving an EQ5 pro synscan and nothing more. That’s good to know about the 16v with no load, however this would drop a volt or two when you connect the mount. But I suppose it’s better to be safe than sorry with the addition of a buck converter.

[DaveL59]

For sure, I figure with these things being so sensitive it'd be better to protect than to risk even a very brief over-volt. I did also place a fuse in the line, I'd posted in another thread about power supplies ages back as I got this sometime in 2019 IIRC.

[bosun21]

1 hour ago, DaveL59 said:

For sure, I figure with these things being so sensitive it'd be better to protect than to risk even a very brief over-volt. I did also place a fuse in the line, I'd posted in another thread about power supplies ages back as I got this sometime in 2019 IIRC.

Where did you get the cigarette plug/2 pin connector?  Thanks 

[DaveL59]

Ahh depends on the pack, mine came with it included

YABER Car Jump Starter, 20,000 mAh 1,600 A Car Battery Jump Starter (for All Petrol Vehicles or 7.0 L Diesel), IP68 Waterproof, Fast Charging : Amazon.co.uk: Electronics & Photo

tho you can buy them separately

Universal EC5 Cigarette Lighter Socket Adapter Connector For 12V Car Battery Booster Car Jump Starter (Shot Lead): Amazon.co.uk: Automotive

[Chefgage]

15 hours ago, bosun21 said:

I know that quite a few members use these as a power source for their equipment. What I would like to know, is are they any good? and can anyone recommend one that they have found decent. 
PS:-  what type of connection do they use? Many thanks  

    Ian 

I use this one

https://www.halfords.com/motoring/tools/garage-equipment/battery-chargers/halfords-6-in-1-jump-starter-power-pack-654898.html?istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istFeedId=367c5610-f937-4c81-8609-f84582324cd6&istItemId=wrirtqtpq&istBid=t&_$ja=tsid:|cid:17363835999|agid:|tid:|crid:|nw:x|rnd:2651873092412831121|dvc:m|adp:|mt:|loc:1007055&gclid=CjwKCAjw7eSZBhB8EiwA60kCWyY___s1_FKFGmZOjWRK23_2jTrPx_Dep4JZXs_E7hNNr9WACDtmaxoCfOsQAvD_BwE

I power my heq5 pro mount, asiair pro, 2 dew bands, astro camera, guide camera, pegusus power supply all off this and it lasts a good few hours.

[lvan]

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Edited October 6, 2022 by lvan

[lvan]

Deleted

Edited October 6, 2022 by lvan

[lvan]

Deleted 

 

Edited October 6, 2022 by lvan

[DaveL59]

A jump starter does have the bonus of being able to serve double duty should you ever need to boost start the car tho 😉

Also the LiPo type are compact and lightweight compared to the big heavy lead battery type and don't suffer volt droop as lead does as capacity is used up, not to mention you can use far more of the rated capacity where lead batteries are pretty much done at 50%.  If you do go for a lead battery, bear in mind that if you don't keep them topped up then lead batteries are toast in no time and you'd need to replace the internal battery. Never leave a lead battery that's flat, but likewise if storing the LiPo type, best to leave them at say 40-60% than fully charged.

[bosun21]

52 minutes ago, lvan said:

Why a jumpstarter? A 12v talentcell power bank will power the lot with ease.

It says the talent cell is only rated at 2A maximum 

[lvan]

Should’ve checked power requirements! Sorry, have deleted posts so as to not misinform others 

Edited October 2, 2022 by lvan

[Carbon Brush]

First thing to check is output voltage when fully charged - they do differ.
Next read the small print on the Wh and Ah capacity of the power pack.
A sneaky trick is to add the cell Ah ratings to make the pck sound better!

What do I mean by this?
If you have 4 cells, each 3V 5Ah, in series, you have a stack giving 12V with 5Ah, or 60Wh capacity.
The liars who describe the products will often say it is a 20Ah pack - because it has 4 cells each 5Ah. Implying 12V, 20Ah which is 240Wh.

Then read the voltage spec for your equipment. Nominal 12V equipment is often tolerant of 15V or 16V. But you have to check the small print.

Second, when you buy one, the 2 pin output will often be completely unprotected against overload or short cicuit.
Flames come to mind.

I did use one a few years back to provide power for a 10" goto dob.
The voltage was OK - I don't remember the figures it was a long time back.
The plugs are easy to come by for a few ££ on ebay/Amazon.
However, you need soldering skills to use them.
I also fitted a PTC thermistor in line for overload protection, which involved a small 3D printed housing on the end of the plug.

So it can be done. But it isn't easy. If you don't have the skills and knowledge, it can destroy equipment and present a fire risk.

HTH, David.

[bosun21]

1 hour ago, Carbon Brush said:

I also fitted a PTC thermistor in line for overload protection, which involved a small 3D printed housing on the end of the plug.

How would one go about determining what value of thermistor is required to offer protection? Thanks 

[Carbon Brush]

Hi Ian.

The thermistor can be rated with various considerations.
The simplest, and safest, choice is to look at the likely load your setup places on the battery pack.
If you add up mount slew current, camera, any heaters, etc. then that is the sort of value you want.
The data for a thermistor gives a hold current (no trip) at 25C, so can be used for astronomy applications.
In round figures, a thermistor will trip in 10 seconds at double rated current. Much faster if the current is further increased.
Don't forget that after trip until power is removed the PTC device self heats so needs a little space around.

I have attached data for thermistors made by Bourns. A reputable manufacturer.
You can get these (or similar devices) from various electronics distributors.

The battery pack should be good for the few amps discharge in astro applications.

Just make sure the cables running from the (now protected) power pack to a distribution box are heavy gauge.
This ensures you have a stable supply at the equipment when load current changes.
You also need to ensure if there is a short circuit, you get sufficient fault current flow for a fairly fast thermistor trip.

If (ridiculous case) you had a 20 metre run of thin doorbell wire between power pack and mount, the cable resistance would limit the fault current.
It would take a long time for the thermistor to trip.
In extreme, with the surplus thin cable neatly coiled, you would get heating and end up with the cable melting.
If you look at mains extension leads, they can only be used at maximum current when fully unwound. This is so they lose the heat generted in cable resistance.

HTH, David.

 

64685_v1.pdf

[doublevodka]

There's a new product which may interest you on FLO - https://www.firstlightoptics.com/batteries-powerpacks/orion-dynamo-pro-155wh-acdcusb-lithium-power-supply.html

[Mandy D]

5 hours ago, doublevodka said:

There's a new product which may interest you on FLO - https://www.firstlightoptics.com/batteries-powerpacks/orion-dynamo-pro-155wh-acdcusb-lithium-power-supply.html

I'm curious as to why it declares 115V a.c. output on the label and has a UK standard BS1363 socket fitted in the photos! 🤣

The Dutch link below gives more information and declares 110 V on the label but indicates 220 V in the text. Inverter output is 100 VA. But look how much more expensive it is ...

https://www.ganymedes.nl/en/product/orion-dynamo-pro-power-supply-155wh-ac-dc/

[Carbon Brush]

As a general rule, for astro work, you are better avoidng the 110V or 220V or 240V products.
You are introducing an avoidable high voltage hazard to a dark and damp place.

Most astronomy kit works from 12V or 5V so can use readily available power supplies.
If you run a laptop that has a higher voltage input (like 19V) you can buy 12V step up adapaters.
Not forgetting your laptop will run usually for a few hours on internal battery.

Slightly off topic. But a valid warning.
The 110V/220V type invertors on general sale often put out a square wave, or at best a 2 step type wave. Not a sine wave.
What does this mean?
If you are trying to run anything with a motor, or a transformer, you should choose a 'pure sine wave' device and preferably check it does what it claims.
I have a pure sine wave invertor. Intended to run my gas central heating boiler this winter should the lights go out.
Charging a laptop, or running other equipment that has a switched mode power supply, you can potentially use the cheaper (not pure sine wave) devices.
However, be aware they can produce voltage transients that can damage the equipment.
Not easy is it🙄

 

[doublevodka]

15 hours ago, Mandy D said:

I'm curious as to why it declares 115V a.c. output on the label and has a UK standard BS1363 socket fitted in the photos! 🤣

The Dutch link below gives more information and declares 110 V on the label but indicates 220 V in the text. Inverter output is 100 VA. But look how much more expensive it is ...

https://www.ganymedes.nl/en/product/orion-dynamo-pro-power-supply-155wh-ac-dc/

Funny enough I thought the same, but in the questions below FLO have clarified it, so I think it's just a stock photo

 

Q1. Is output from the UK 3-pin AC socket 120V or 240V?

Output is: AC 230v 50Hz (EU/UK version)
AC output power is: Continuous 100W output, Modified Sine Wave

[Cosmic Geoff]

The jump starters are relatively cheap, (often cheaper than a lead-acid 'astro power pack'), do the job and can also be used for starting your car, inflating tyres, and emergency lighting (depending on model).  They all seem to have a cigar lighter type output, and I doubt it matters much what model you buy for primarily astro use.

I also have a Celestron LiFePo power pack, which was relatively expensive but said to be longer lasting than lead-acid batteries. It is light in weight for its capacity and also works well as an emergency light (good for working under car, or slug-hunting).   The output could be as much as 16v when freshly charged, but this has not been a problem in two or more years of use with three of my mounts.   The output will drop slightly if you don't use it immediately after charging, and will also drop a little under load.  The 5v USB output may also be of use to some.

I would recommend either of the above for the O.P's rig. No need to buy anything exotic,, suspiciously cheap or any extra converters. 

[Carbon Brush]

1 minute ago, Cosmic Geoff said:

LiFePo power pack, which was relatively expensive but said to be longer lasting than lead-acid batteries. It is light in weight for its capacity

In round figures the power to weight ratio, and power to volume ratio, for lithium are about 1/3 of lead acid.
A big help if you are carrying lots of kit to a dark site. Less relevant for the back garden.

Lithium gradually degrades with each charge and discharge cycle. Typically hundreds of cycles to end up with 2/3 of original capacity.
Different cell manufacturers make different claims.
But given cloudy nights and all the other astro problems, you can get many years from lithium cells.
Lead acid starts to degrade from the day the cell is assembled. You can't do anything about it.
So for astro use, a lithium pack will usually outlive a lead acid pack.

There is much more. But the bottom line is that I wouldn't buy a lead acid pack for astro kit.

HTH, David.

[Cosmic Geoff]

What is the lifespan of a LiFePO4 Battery? | RELiON (relionbattery.com)

This claims that a LIFePo battery will last for thousands of cycles, and last 10x longer than a lead-acid.  

(If charged every 10 days it should in theory last longer than the mount and telescope. 🙂).

[bosun21]

I have ended up buying the Orion Dynamo Lithium power pack from FLO to go with my Celestron LiFePo I already had. Considering the amount of nights I get to observe with the weather, it will be a while before I make a considerable dent in their charging cycles.

[900SL]

Lifepo offers three great advantages. A flat discharge curve to 90% DoD, light weight and theoretical long life

Offset this against high initial cost and the fact that the support electronics in the battery bank may fail well before the cells.

I use twin 40Ah AGM deep cycle batteries. Light enough to carry singly, good service life, spill proof and you can run them down a fair bit without going below 12v.

Connect in parallel for all night performance, missus