What is the component R47 in the 48V LiFePo4 Battery CHARGER

[MickaelM]

Hello,

One component of my battery charger BURNT.
I have opened the charger and I can see that the component R47 is burnt. (R47 is the name of that comonent as written on the main board of the charger)
Would someone be able to tell me what TYPE and RATING this component is ?

My assumption is that:
The burnt component is a capacitor.
It is approx. 1 cm diameter.
In order to replace it, I need to know the rating, the max voltage + whether it's directional.

Thanks for your help.
Do not hesitate if you need some more information.
Best regards,
Mickael MARTIN

PS : Additional information: The charger brand name is Mebo (or Omebo ?) and the S/N : MB1212281804
(output 58.4VDC / 3A)

[Bikemad]

Hi Mickael andto the forum.

That component looks like a PolySwitch resettable fuse (not a capacitor) but I'm not sure what the current rating is.



I assume it is fitted on the output side of the charger, as the "RF60" on the failed item refers to a 60V voltage rating.

The highest current 60V PolySwitch I could find was 3.0A, with a hold current of 3 Amps (and a trip current of 6 Amps) which will hopefully be suitable for your charger.



Unfortunately, without knowing why the component has failed, it is difficult to know whether simply replacing the component will cure the charging problem, as there could still be another fault somewhere within the charger's circuitry that has caused the original component to fail.

I'm guessing that these PolySwitch fuses are not polarity specific, otherwise I would expect them to be clearly marked + and - if they were. 

EDIT:
After further carefully studying of the picture you posted, I am now wondering whether it is actually marked "RF60 090B" like the following:



These are also rated for 60V use, but only 0.9 Amp current. 

Have a really close look at your failed component with a magnifying glass (or jeweller's loupe) and see if you can make out the digits on the lower row, as this appears to indicate the current (090B = 0.90A).

Alan
 

[MickaelM]

Wahoo, your answer is hugely helpfully to me.
I am very greatfull...
I confirm, it's located at the output side of the charger and it seems written "RF60 090B" as you said.
I'll try to double check the writing on my component before replacing it.

FYI: I'm very ashamed to explaine why it burnt... but basically I made a stupid mistake and plugged the charger on the 48V battery with reverse polarity after a small repair work on the cable! (no comment please )
So I hope that only this component burnt
I just have to find a dealer for these polyswitches, replace and see. Edit:you also provided an ebay link! Amazing!
Thanks again for your help.

[Bikemad]

If it is "RF60 090B", I am wondering why it is only rated for 0.9A when the charger has a 3 Amp output, unless only a small percentage of the full charging current actually passes through the PolySwitch fuse.

Alan
 

[MickaelM]

I agree!??
I would have expected a 3A nominal current as you orignially suggested.
Anyway I have placed the order... I just have to wait 10 to 40 days to receive it and make the test...

[MickaelM]

Thanks Bikemad for your help...
I received the poly switch today, I replaced it (as well as the fuse)... and the charger works again !

[Bikemad]

It's good to know that it is now working again.

Alan