My portable rechargeable power supply (mod)

[Asim]

Hi everyone

couple of months ago I decided to build a portable power supply but never had the chance until now. This is a thread i opened at that time (https://www.eevblog.com/forum/projects/opinion-needed-on-lm2956-based-portable-power-supply/msg479340/#msg479340 )

one of the guys asked me to post my work so here it is.



materials used:
1. LM2596 based digital supply http://www.ebay.com/itm/400561586157 and here is a review about it

2. lithium batteries

3. Protection PCB for 4 Packs 14.8V Lithium w/Balance http://www.ebay.com/itm/Protection-PCB-for-4-Packs-14-8V-Li-ion-Lithium-18650-Battery-4-8A-w-Balance-/261217818070?pt=LH_DefaultDomain_0&hash=item3cd1cb95d6

4. a bigger 7 segment display

5. a fancier push buttons

6. miscellaneous



I de-soldered the 7 segment, push buttons and the LEDs and made my own PCB as the front panal



The unit is rechargeable all what's needed is to switch it off and recharge it from the input jack at the back.


The dimensions are  14 cm *10 cm*6 cm




and DONE.

[Zero999]

That's a nice module.

What's the output voltage range?

Have you measured the current?

How long does the battery last for?

[Asim]

That's a nice module.

What's the output voltage range?

Have you measured the current?

How long does the battery last for?

"What's the output voltage range?"

the module itself can take 40V input and give 36 output ( didn't check it though as I don't have that voltage )
for my unit it gives an output of 0V to 16.6V at fully charged batteries.

"Have you measured the current?"

I did, it is accurate enough, my dummy load blew up so I can't test it extensively 

"How long does the battery last for?"

what is your current consumption ? it all depends on your loads

[Zero999]

Sorry I meant to ask you about ripple too?

It would be interesting to see the efficiency at different loads and voltages.

[Asim]

Sorry I meant to ask you about ripple too?

It would be interesting to see the efficiency at different loads and voltages.

I don't know as I don't have the setup needed for measuring the ripple ( no dummy load to start with )

but I can tell you that it uses LM2596 regulator, if you check the datasheet it would give you a rough idea about the performance expected  from the device