External Battery

[shropshire lad]

I have a golf trolley battery ( golf ..lol .. thing of the past at the moment) ... would I be ok to use this to power my AZ-GTI mount.

.

 

[shropshire lad]

Anyone got any advice on this please.... don't know if it's too powerful (20amps) and will cause a problem.

 

[scitmon]

I'm certainly no expert so don't take this as gospel, but whatever you attach to a battery will only attempt to draw the amps it need.  So if your mount requires 5 amps, the battery will only give it the required 5 amps.

 

[Neil H]

9 minutes ago, scitmon said:

I'm certainly no expert so don't take this as gospel, but whatever you attach to a battery will only attempt to draw the amps it need.  So if your mount requires 5 amps, the battery will only give it the required 5 amps.

 

Hi I second that should run it for hours ,but I would put an in line fuse in so if anything goes wrong the fuse will blow not your main board

[wulfrun]

4 hours ago, shropshire lad said:

Anyone got any advice on this please.... don't know if it's too powerful (20amps) and will cause a problem.

Too powerful would be using the wrong voltage (too high). If your device is rated 12V, then that battery is fine. It'll draw whatever current it requires, the battery isn't 20A it's 20Ah. That means it can supply (in theory) 20A for an hour or 2A for 10 hours or whatever. In reality the rating is usually for 20hr, so 1A for 20 hours but at 20A it might be only half an hour.

The main thing is to have an in-line fuse, physically as close to the battery terminal (positive is conventional) as practical - in case there's an accidental short-circuit or fault. The other thing is not to over-discharge the battery and always re-charge after use or if unused for a month or so.

Edited February 5, 2021 by wulfrun
clarity

[shropshire lad]

Thanks for your replies ... any idea what size (amp) fuse I should use?

 

[wulfrun]

7 minutes ago, shropshire lad said:

Thanks for your replies ... any idea what size (amp) fuse I should use?

Have a look on the mount for a rating-plate or in the manual*. That'll probably show a worst-case figure but go a little higher to save on nuisance-blowing of your fuse. I'd guess somewhere around 2A if you can't find any better indication. If it blows regularly without an obvious cause, increase it a bit, maybe 5A. However you connect up, be extra, EXTRA careful not to reverse the polarity or your mount will almost certainly die. In fact, I recommend you fit a suitable diode somewhere in the line so it can't happen.

*FLO's spec suggests it uses 0.75A but there might be spikes a bit higher.

[Doug64]

Hi,

 

I've used my 12v lithium golf battery for about 5/6 years without any problems to my HEQ5 mount.

Doug

[pete_l]

16 hours ago, shropshire lad said:

Thanks for your replies ... any idea what size (amp) fuse I should use?

A fuse is not a universal protection.  For example it won't stop your gear being damaged if the polarity is wrong (positive and negative swapped over). At best, it will prevent a fire from starting. Although that is a good thing to stop!

[shropshire lad]

Thanks for your replies folks, much appreciated.

 

[Geoff Lister]

The motors in a golf trolley are likely to draw much more current than your mount, so plenty of capacity. Probably best not to take more than 10Ah out of it before recharging.

A fuse is designed to protect the wiring between the power-supply and the load; the load should be designed to protect itself.

I measured the current taken from my mounts:- 

I would expect the AZ-GTI mount to have a current consumption similar to that of my Skymax or Cosmos mounts.

This is a selection of my supplies:-

The white cable is multi-strand bell flex. It is designed for low voltages, so it is very flexible as it does not need the outer insulation of mains wiring - and being white, it shows up better in the dark. I did not fit a fuse on the red/black wires; they are short and thin, and act as their own fuses if I short out the power jack. The plug-top supply provides its own current limiting.

A fuse's nominal value is the current that it can carry continuously without blowing - for most standard fuses, the time to blow shortens as an inverse function of the square of the fault current. A fuse with a low rupture current will have a higher resistance than a higher value one. It's worth going for a 3A or 5A fuse, close to one of the battery terminals.

Geoff

 

[rickwayne]

I was going to suggest the same -- unless it's a deep-cycle battery, best not to whang on it too hard or you'll shorten its life.

I have one of these little meters wired into the harness for my battery (which is a deep-cycle). Takes next to no current, and it will not only give you the voltage going out, but also how many amp-hours you've consumed since the last reset. Very nice feature is that you can set a voltage-level alarm, which blinks the blue backlight. So you can safeguard your battery from too deep a discharge, when the voltage starts to drop, it will get your attention.

Super-duper easy to wire up, no soldering required. I just stripped the wire ends and applied copious amounts of tape.

https://www.droking.com/panel-meter/dc-ammeter/4in1-Voltmeter-Ammeter-Power-Meter-Energy-Meter-DC-6.5-100V-20A-2000W-0-9999kWh-LCD-Display-Blue-backlight-Digital-Meter

I started with a 14 Ah battery which ran my CEM25P, Raspberry Pi, and cameras quite nicely for a few hours. A friend loaned me her 26 Ah monster, which in warm weather will go all night.

[shropshire lad]

Ok, fitted 3amp fuse close to positive terminal and connected to my AZ-GTI and it works a dream ..... hoping for a clear night to give it a full test.