"Mini Jump Starter" as power bank?

[mental4astro]

Hi folks,

I've just been made aware of these "Mini Jump Starters" (http://www.ebay.com.au/sch/i.html?_nkw=mini+jump+starter&_fromfsb=0&_trksid=m270.l1313&ul_noapp=true). Some places describe these not just for jump starting a car, but also as a power bank for 12V appliances and even charge computers with built-in step up converters for various voltages. Stored power varies greatly between these, as build quality does too I suppose. The cheaper ones don't really excite me safety wise.

Any one have any knowledge of these as a power source? My father in law has picked one up for his truck just in case, and to charge is phone in the field, but he isn't using any 12V appliances, etc. These units are so blooming small and light weight, but pack so much charge! Could mean the end of lugging around big batteries.

Alex.

[casstony]

There are different types of lithium batteries and I'm lead to believe that some are safer than others. Some people using RC helicopters, etc store their Lithium batteries in fireproof steel boxes to avoid spontaneous combustion burning the house down.
The newer Lithium Iron Phosphate batteries are supposed to be a lot safer (or so I've heard), so I'd check the composition of the particular battery you're buying.

The Celestron Evolution mount uses a LiFePO battery and it works very well.

[silv]

Sorry, no hands-on experience here.
But I was thinking of getting one of those - a proper one, not one equipped with cell phone batteries :D (those all come in blue plastic cover, btw).
It's ideal for me, too, because I use a push bike to get anywhere dark.

So I read the customer reviews on Amazon - with an eye on whether people use them as constant power source or only to charge devices.
And yes - people do and successfully so.

What a relief, aye!

[rrussell1962]

I have been using one for a while now. From memory it is 17 amp hours. Excellent for a night with the mount, but I did run it down using it with a couple of dew heaters together. Mine has lovely bright electric blue lights to indicate the change level! duct tape required to mask them. Expensive, but very convenient.

[casstony]

It looks like the Lithium batteries that are as cheap as lead acid gel batteries are of the cheap and nasty variety. The LiFePO batteries appear to be more expensive than the equivalent lead acid, but they will weigh much less.

[bugeater]

Small Lipo batteries can dump a lot of juice pretty quick, hence they can jump start a car. I've jump started my motorbike with a small Lipo a few times. But the storage capacity doesn't need to be too high to do this. The ones I have are for r/c helicopters so they are made to discharge quite fast.

But as Tony has said, they can be a bit volatile. Though to be fair, I've seen a heap of Lipos poorly treated (such as crushed to half their original length in a crash) and have only seen them go up once or twice in my whole time using them (many, many years). The main danger seems to be if you charge them incorrectly.

LiFePO are meant to be much safer though and in fact my motorbike battery is one of these. Much lighter than the lead acid battery it replaced and can handle sitting around not being used a lot longer.

[Occulta]

Alex

I took mine to Woleai Atoll for the March eclipse and it performed flawlessly.
If you do get one make sure it has both the 12V and 5V outputs.
I used mine to power the mount and the USB3 hub with no problems. Holds a charge for a long time and does have the higher voltage option. Velcro holds it. [Note the image does not show power leads]
I can't give you a usage time as I only wanted the C2 - C3 part of the eclipse. I will be taking it to the US next year. Also no issues with Customs or Border security going through Guam. It was carried on my person.

Chris

[casstony]

I just remembered we recently gave a Parrot drone to a friends kids as a birthday present. The kids left the LiPo battery on the charger for too long and it burned the floor of the house, so you do have to be careful.

[bugeater]

I think that probably speaks to the quality of the charger and battery rather than the technology itself. After all, it's the battery tech in all our mobile phones.

[mental4astro]

Thanks guys. Need to look carefully into these then to find the most appropriate one. Thanks for the tips.

Alex.