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Dewalt 5ah Battery same fault 3 repair options

Doctor Lefthandthread

4,604 views

Welcome to an undisclosed location in County Tyrone.

Three young DeWalt 5Ah batteries arrive at the surgery with the same failure… they will not charge or work. Doctor Lefthandthread investigates this common DeWalt battery fault and discovers broken fusible links caused by overload damage.

Are these DeWalt batteries suffering from bad design? Or have they been abused?

In this battery repair video we diagnose the fault, explain the difference between old and new DeWalt battery designs, and perform three different repair methods using donor parts, fuses and nickel strip.

This video covers:
DeWalt battery not charging
DeWalt battery repair
DeWalt 5Ah battery fault
DeWalt XR battery repair
Battery fusible link failure
Power tool battery repair
Cordless tool battery troubleshooting
Battery overload damage
M18 / DeWalt battery surgery
How to repair dead batteries

Remember: power tool batteries contain high energy cells. Battery repair should only be attempted by people with suitable knowledge and equipment.

Doctor Lefthandthread
Defacto power tool battery doctor of the internet.

#DeWalt #BatteryRepair #PowerToolRepair #DoctorLefthandthread #DIY

12 Comments

@girlfar4079 3 months ago (edited)

I have repaired battery like this with a car fuse i soldered in, works great too. Also keeps the user safe in case of short circuit, and easy to put a new in next time. Yes many do abuse their battery's, that's very true. Mine all still working after years.

@shifty277 3 months ago

Tell that owner to get the 8ah Tabless battery - It's the most affordable tabless battery from the big boys! £120 I can get it today and keep the 5ah on the small low power tools - combi, impact etc, tabless for the saw,grinder & sds.

Simples.

Thanks for continuing your work - really enjoy your battery content.

Thumbs up.

@SimpleDudeDoStuff 3 months ago

I have same batterys for years and zero issues

@fishwag 12 days ago (edited)

This is a design fault because there is no reason why a removable high amp fuse could not be fitted.

@jeslookn5470 2 months ago

I became a member. Are you answering questions in the comment section or is there an email address to ask questions?

@mrdiggie3321 3 months ago (edited)

Giving the guy a battery back he's likely to abuse again with nickel strip instead of a fuse was definitely the worst choice here. You could have probably soldered on a cheap auto fuse.

@shifty277 3 months ago

Also what are your thoughts on the BMS board of say pre 2025 boards and the newer cardboard looking boards?

@daleclose1981 3 months ago

I have a flexvolt battery and the back joint that goes to B- is blown. I went to fix with nickel strip and it was getting hot. Do you think it's dead?

@brianmccolgan7623 3 months ago

Do you fix powerstack batteries

@jeslookn5470 2 months ago

I used this method to repair a battery that was used to jump start another battery. The thing that concerns me about this method is the solder will melt before the fuse blows. Am I correct? Does it matter?