Blown chip fuse replacement?

Thread Starter

tab a

Joined Jan 14, 2015
36
The 56v battery in my EGO string trimmer was submerged during a flood we had. Dried it out and checked all the batteries--which seemed good. Only problem I found was that a chip fuse, between the two 28v strings IIRC, was blown. I soldered a short piece of stranded insulated wire--maybe about the size of phone cable wire--in its place and the trimmer seems to work fine.

The chip says 3.0mm on it. I couldn't find anything similar, though not really sure best to search for it.

Assuming I keep it out of water, any good reason I shouldn't use it as is?

Thanks!
IMG_0505.jpg
 

crutschow

Joined Mar 14, 2008
24,360
any good reason I shouldn't use it as is?
Only if you don't care that a future short might cause a battery fire. :eek:
Recommend you remove the wire and measure the current where the fuse was when the trimmer is on.
Then replace the wire with a fuse rated for about 150% of the current you measured.

What are "two 28v strings IIRC"? o_O
 

Thread Starter

tab a

Joined Jan 14, 2015
36
I can do that. What's the correct name for this type of fuse, so I can search for it?

With the fuse blown, I measured 28v across each of the 2 battery 'strings'. Tied together by the fuse = the rated 56v.

Thanks!
 

bwilliams60

Joined Nov 18, 2012
1,259
I believe Crutschow was asking what amperage was being drawn through the fuse, not the voltage being supplied. You would need to place an ammeter in series with the circuit to take this measrement. If youve never done it before, you may want to Google "How to use an ammeter". When you figure out the amperage draw, multiply it by 150% to get you a safe fuse rating that you can use.
As for th chip you pulled, never seen one before but 3mm suggests something like a fusible link. They are measured standard or metric but you would have to look up the rating for it. It is a surface mount fuse
 

Thread Starter

tab a

Joined Jan 14, 2015
36
I do know how to measure amps but am not sure how best to do that here, as wiring is tough to get to with battery in place. Maybe somewhere in shaft, or near head?
The 'ribbon' I can see in the chip seems to be exactly 3mm wide, FWIW.

Thanks.
 

bwilliams60

Joined Nov 18, 2012
1,259
If you have a wire in place of the fuse, you could use an inductive ammeter or amp clamp around the wire or lift one side of the wire and put the meter in series with the circuit.
 
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