Skywatcher/Celestron 17Ah Power Bank Internals

[GeekTeacher]

Sorry if this is in the wrong topic area, newbie here.  I've bought some used gear which includes a Skywatcher 17Ah mobile power bank with a dead battery. On opening the unit to replace the battery one of the wires to the sliding switch on the top of the handle has come away from its circuit board and I can't tell where it should be attached. I've found some internal photos of this unit in this forum, but none are clear enough to show me where the switch wires go. Does anyone have  a photo with the details I need or perhaps even a circuit diagram please? I believe my unit is identical to the one badged as Celestron. Or if anyone could point me in the right direction for finding the info I require it would be greatly appreciated. Here's hoping ...

Edited November 5, 2019 by GeekTeacher

[happy-kat]

Hi

Maybe @Dave T might be able to help shed some light on your question.

[Tomatobro]

Could you post a picture of the board?

[GeekTeacher]

Yep, I've attached the best photos I can take. I've since realised that the top switch only controls the large white light (I thought it was the main on/off switch when I originally posted).  

In the photos the loose (thin) wire is shown dangling over the larger circuit board.  I think it should probably be attached to the smaller board to provide power to the light.

One of the light's wires goes to the top switch and the other of the light's wires goes to the smaller circuit board.  So it just needs a connection to be made (by sliding the switch) to supply power to the large white light (not shown).

The new battery is powering my mount, the USB sockets and the radio as it should, so I only need to know where the loose switch wire goes to, thanks.

If anyone is interested the Powerline PL17-12 from Tayna.co.uk fits inside the case OK.  I don't know how good it is yet but it was only £25.

Thanks

Edited November 6, 2019 by GeekTeacher

[Carbon Brush]

This is the first time that I have seen the innards of one of these power packs.

I'm a bit worried that I can't see a fuse in wiring immediately from the battery.
I assume (hope) it is somewhere along the thick red wire.

If there is a short circuit in the wiring, the battery will happily deliver 200 amps and more for a short time. Quite enough to start a fire.
Well actually enough to start a car engine - this battery size is often used in car start/charge units.

May I suggest removing the battery positive lead while working on the equipment?
After working, make up a sleeve to cover the battery postive connection.
It can be insulating tape, sellotape, bath sealant (non corrosive variety).
Basically anything that makes accidental battery contact difficult.

When you resolder the dangling wire, cover the joint to the PCB with glue or silicone sealant (non corrosive again).
Anything will do. It acts as a strain relief so reduces risk of the wire falling off when the case is next opened.

HTH David.

[Paul M]

I have one of these. Bit too late to go outside and take it apart and I'm up for work at 6 am tomorrow. If you don't get it sorted before then I'll have a look in mine tomorrow evening.

I have been inside mine already. I hadn't used it for a long time and I think something was left on (radio??) and it drained the battery to a level that caused the internal charging circuit to refuse to charge it. So I took it apart and resuscitated it with a constant current charger (slllowwwly) and it then worked ok.

Anyway, as above. I'll check in on this thread tomorrow and see how you've gone on.

@Carbon Brush The inline load fuses are mounted in the case in old fashioned screw top fuse carriers. 

[GeekTeacher]

Hi Guys, sorry for the late reply.  I worked out where it had come from when I realised it was only the switch for the white headlight.  It just needed connecting to a positive power point on the circuit board and I'm assuming the one I chose is the one it came off. Anyway, it now works.  <Carbon Brush> There are two fuses on the outside of the case, one is removable and is rated at 2A the other is a resettable 15A type. <Paul M> I hope you didn't take all those flipping' screws out for me! Thanks for your offer of help.

[Paul M]

6 hours ago, GeekTeacher said:

Hi Guys, sorry for the late reply.  I worked out where it had come from when I realised it was only the switch for the white headlight.  It just needed connecting to a positive power point on the circuit board and I'm assuming the one I chose is the one it came off. Anyway, it now works.  <Carbon Brush> There are two fuses on the outside of the case, one is removable and is rated at 2A the other is a resettable 15A type. <Paul M> I hope you didn't take all those flipping' screws out for me! Thanks for your offer of help.

Glad you got it sorted.

I'd actually completely forgotten about my offer so it's just as well you did sort it! Chicken dinner was sat waiting for me when I got home from work at 7 and I was then surrounded by hyperactive children proffering the chocolate cornflake crispy crunch cake thingies they'd been making.... I digress

Power tanks: Mine might not actually be fully screwed together presently. Since my last battery problem the battery has completely died. It shows only a few mA's of current with a charging voltage of  13v-14v so it's done for!

Might replace it or I might make up a bespoke heavy duty supply using a high capacity leisure battery on some kind of trolley. I don't ever use the torch or radio or even the USB power outlet on the power tank. For now I'm using a mains power supply and extension lead.