Jaycar LiFePo4 24Ah jump starter power banks?

[luka]

Just found these (https://www.jaycar.com.au/lifepo4-12v-270a-jump-starter-with-lcd/p/MB3760) power banks at Jaycar. Does anyone have experience with them?

The pack claims 45Ah capacity which, if true, could possibly run an EQ6 + imaging gear the whole night.
All in a size a bit smaller than a brick.

[Kunama]

I think it is likely 45Ah @ 3.7v , I suggest you check with them.
a 45Ah @ 12v+ is a much larger LiFePo4.... and many more $$$

I use a DryPower Golf Cart Battery which is 16Ah @ 12.8v and is double the size.... but comes as a kit and powers the AZ-EQ6 for a couple of nights...

[casstony]

I have a larger capacity one of those from ebay and it's about 4.5 Ah and maximum 3 amps, fine for alt/az mounts for a few hours but no good for modern equatorial mounts which often draw more than 3 amps during a slew.
The technical details are printed on a side of the battery cover that is not clearly shown in the ad.

[LewisM]

asked about these not long back at Jaycar. The techie said it was actually milliamp hours, and that with around a typical 2 amp draw (like mounts slew, laptop etc, it's maybe good for 3 or 4 hours max. He said the details are incorrect.

They may have changed it.

[casstony]

How do you have the battery set up Matt, with regard to connections?

[luka]

Thanks, I knew it was too good to be true.

Kunama, I think you are right. I found few other models and, if specified, the capacity is always at 3.7V and not at 12V. This is very misleading advertising considering the pack is outputting 12V and not 3.7V.

The capacity is probably even less for this particular model as the LiFePo4 batteries usually run at 3.2V and not 3.7V like the LiIon batteries.
45Ah@3.2V = 12Ah@12V... should be enough to run EQ6 a whole night (especially if it is mainly tracking and not slewing much)

Just noticed they also have a larger model (https://www.jaycar.com.au/lifepo4-12v-450a-jump-starter-with-lcd/p/MB3762), 58Ah (says 58WH which is likely a typo - or maybe it is 58Wh???). This one has two 12V barrel connectors which would make interfacing to the mount easier.

[Kunama]

I installed mine into a Kinchrome Safe Case and drilled the case for Merit plug, Cig plug, fuse holder and On/Off switch

[casstony]

That's the one I have. With a moderate amount of slewing on a CPC mount it lasts for a few hours.
My Advanced VX supposedly has a maximum current draw of 3.5 amps so I don't use the battery with that mount. For imaging I have a 38 Ah deep cycle battery.

[luka]

The physically larger battery is 58Wh (the zoomed images clearly show Wh printed on the battery). On the other hand the smaller battery is 48Ah. Note the different units.
The 48Ah is a pointless number unless we know the voltage that was measured at. If the voltage was 3.2V (standard for a LiFePo4 cell) then the smaller one almost has 2.5x the capacity of the larger one.

Gotta love the Chinese labeling :shrug:

[raymo]

I bought my son in law one of the larger ones from Jaycar, but had no reason
to look at its amp/hr rating, as its primary purpose is short duration high amperage use, not powering devices.
However, as the claims on the box seemed to be over optimistic, we stuck a flat battery into his Mazda 2.5lt turbo diesel, and got seven easy starts and
a struggling eighth one. Pretty damn good, I thought.
raymo

[tgstorer]

I have 2x 450amp Batteries from Jaycar. I use them on my Losmandy GM811G mount. The Battery lasts several nights of observing with a fair amount of slewing. Highly recommend this battery. Be sure to get the model with 12V and 19V outlets. The 12V is actually 13.67V no load, so works well with Gemini 2 System.

[phomer]

Luka,

I disagree, Wh is a more useful measure than Ah because it gives you the capacity. For example 48Ah tells me nothing unless I have the voltage whereas with 48Wh I can calculate that at 12V it would give me 4Ah. You can always get a voltage converter if you require a different output voltage.

Paul

[luka]

Paul, that is the same as what I said. To quote myself:
"The 48Ah is a pointless number unless we know the voltage that was measured at...."

[floyd_2]

Just wondering if anyone has used one of these with an AZ-EQ5. A123 batteries are a great thing to have as they're very forgiving.

[floyd_2]

Just to answer my own question in case anyone else was wondering - this unit will run an AZ-EQ5 for about 2 1/2 hours of observing in AZ mode (ie. running both drives concurrently at all times) including initial setup and slews from object to object - loaded up and balanced with an AR127 and C9.25. I tend to look at objects for quite a while, so your mileage may vary depending on your viewing style. At 2 1/2 hours the battery was showing 34% and was, in my opinion, starting to deplete too quickly so it was time to turn it off and charge it up. Not bad for an ultra portable A123 power supply that you can jump start your car with. It'll get you by for a short session, but is certainly far too light weight for anything more than that.