Is 11% over voltage enough to cause heating?

[raymo]

Concerning my previous thread about Nano Tracker heating problems.
The tracker is rated 3.6v-4.5v. Would 5v from my laptop which is about 11% over the rated max, be enough to cause the overheating of the tracker.
raymo

[leon]

A simple answer Raymo, yes that is getting up there,

I had a similar problem not related to yours of course just two days ago. when, the Charger in the Caravan got over heated and cooked the Battery it was to hot to touch, it was close to exploding, and bulging.

I took it to the Battery Place to see why and they immediately rushed it out side and said, " man you are a lucky bugger" the whole van could have burned to the ground

When things go wrong in the battery or charging phases with this sort of stuff be careful mate.

Leon

[raymo]

That reinforces my decision to stick to batteries.Cheers
raymo

[Ukastronomer (Jeremy)]

Something rated 3.6v-4.5v is not rated at 5v for a reason, 4.5 to 5v is a large percentage in a small amount

[raymo]

I'd like to know why the device is fitted with a MiniUSB external power port
when USB supplies 5v and the unit is only rated to 4.5v. I'll make up a 4.5v
power pack and see if it then overheats when using the power port.
raymo

[redbeard (Damien)]

Originally Posted by raymo

I'd like to know why the device is fitted with a MiniUSB external power port
when USB supplies 5v and the unit is only rated to 4.5v. I'll make up a 4.5v
power pack and see if it then overheats when using the power port.
raymo

It could be that it is designed to run on rechargeable batteries as well as standard batteries and the mini USB is a charging port.
That would explain standard batteries getting hot as you are charging them, where rechargeables would not get hot. Worth a test?

Time to find the manual or contact the dealer?

Cheers,
Damien.

[raymo]

Hi Damien, I have a PDF of the manual, and it states that running off
rechargeables is not recommended as 3 fully charged rechargeable AAs only
just supply the minimum required voltage [3.6v], so I always have used 3 normal AAs. The port is definitely for an external power source, it is listed as such.
You have the wrong end of the stick; It is the hand controller [ actually its motherboard] that gets hot when running the tracker with external power, whether you leave the batteries in or remove them. Also the green power
light on the controller is brighter when using external power, as is to be expected as USB supplies 5v as opposed to 3 x AA =4.5v.
I bought it online quite a while ago, but have only recently tried external
power. It looks like I'll have to find a way to contact Sightron.
cheers raymo

[redbeard (Damien)]

Originally Posted by raymo

Hi Damien, I have a PDF of the manual, and it states that running off
rechargeables is not recommended as 3 fully charged rechargeable AAs only
just supply the minimum required voltage [3.6v], so I always have used 3 normal AAs.

Fair call, but didn't you quote in the other post that the 'new' unit was designed for rechargables, Alkaline, etc?

The port is definitely for an external power source, it is listed as such.

I agree that it makes no sense to supply 5v USB when the unit requires 4.5v, unless there is a very low dropout voltage regulator in the unit. But the LED brightness kinda rules that out.

You have the wrong end of the stick; It is the hand controller [ actually its motherboard] that gets hot when running the tracker with external power, whether you leave the batteries in or remove them.

Cool, I had a look online so now I know what it is as there was no mention of a hand controller in the posts, (I haven't used a tracker). Stick with batteries until you get a solid answer from the maker.

What was the end result with the USB lead and wiring as you mentioned it was different internally? USB is USB, maybe they have a special power supply with a custom wire USB plug?

Good luck and keen to hear if you get a fix.
Cheers,
Damien.

[raymo]

Hi Damien, Thanks for your continued interest. I looked back through all
my posts on this subject, and I didn't state anywhere that it is designed to
run off of rechargeables. I have always run it off 3xAAs.
I had an electronics whiz pull it apart and check it out. It turns out that I
was using the correct cable for external power, but it cannot handle 5v, as
there is no regulator built in. He said the manufacturer stuffed up. I have
located 1.5v supposed rechargeables at Jaycar; apparently they can't be charged as many times as the normal 1.2v ones can, but still much cheaper
to run than disposable batteries. They were out of stock so had to order them in. They are a great little tracker, and new features are frequently added.
The one before mine didn't have the external power port. The one after mine can use autoguiding.
raymo

[redbeard (Damien)]

Good ol manufacturers. I'm glad that's sorted for you.

Just for reference here is what I was referring to, and I won't bother you anymore

Originally Posted by raymo

Thanks everybody. The tracker is rated to work from 3.6v to 4.5v.
I used to use 3 AAs =4.5v, never rechargeables, then switched to the laptop as a power source. I used the cable that is used to transfer images from the camera to a laptop because the sockets on the laptop and tracker matched the USB and apparently Mini USB fittings on the cable, however on closer
inspection I have discovered that the plug and socket at the tracker end of the cable whilst superficially the same are in fact different internally, so I think that is the problem; the moral of the story is to never assume anything.
I'll get a new Mini USB cable and see if that fixes the problem.
Incidentally, this is the later model that is designed to run on rechargeables,
alkalines, or an external 4.5v power source; the previous model was not
equipped for external power. Yes I am lucky that it still works.
Thanks again.

[raymo]

Bother me all you like, my abject apologies; I missed that.
raymo