Replacement DeWalt Battery

[littlespark]

My little yellow friend, Dewalt 18v combi drill has a broken battery. It wont charge.
Its been going for a good 5 or 6 years now, but neither battery holds charge well.
A quick look online gives prices of round about £100 per battery for a genuine replacement. I'm going to look at the sources Pirate mentioned on another thread, but in the meantime, I have a question.
I can get unbranded knock-off batterys for £40 for 2 from a popular online department store that I may have a £20 voucher for. Does anyone know how good these are? Will they be as powerful as the genuine dewalt? Are some knock off brands better than others?
The battery in question is DeWalt 18v 2.6Ah NiMH model number DE9503

Further question. I only think the battery is faulty as the charger flashes quickly indicating a fault. Is there something inside the battery that can be repaired?

 

[pirate]

This would do the job
DeWALT DE9503 18v 2.6ah Nimh Battery | Tools and Parts Direct - https://www.toolsandpartsdirect.co.uk/accessories/dewalt/batteries-accessories/18-volt-batteries/dewalt-de9503-18v-2-6ah-nimh-battery
and you could get 2 for £100.

 

[littlespark]

Looks like the ones I saw on am*z*n. I’ll have a good look round before purchase, I still have 1 good battery.
My father in law has the same drill that he never uses. Might need to swap over my batteries for his next time I visit

 

[123]

At £100 for 2 Nimh batteries - it might be money better spent on getting a new drill with Li-On Batteries.

 

[Phil Thompson]

You’ll get a 5ah battery brushless combi hammer drill and charger for £159 or less, which would almost equal your 2x2.6 batteries, but the brushless should use less power, so drill for £59 basically.
Other options I saw are
With a 9ah for £279 or less
Or x2 5ah for £229 or less, that was just on a quick search.

Various kits available too.

Be more economical imo, plus options to buy body only for other items down the line.

 

[littlespark]

Thanks everyone for suggestions, but i'm on a mission now to mend and make-do.
Both of the batteries are giving a reading of over 19v on my multimeter, but when plugged into the drill, the faulty battery gives no life at all.
These particular batteries have a 3rd contact between the 2 main contacts. Reason? Could that be what tells the charger that the battery is broken?
Shield the contact and fool the charger into thinking the battery is ok and charge it, or could that cause a major problem (boom!)

Maybe one of the contacts isn't connecting when plugged into the charger?
I'll keep you posted on how things go...

 

[HandySparks]

The 3rd contact on the battery is likely to be for a temperature sensor in the battery pack which will stop the charger fast charging when it gets too warm.

If you're still using NiMH batteries, I'd be inclined to look for a new Li-Ion tool set with batteries and charger at a good price.

 

[Andy78]

Could be a problem on the drill PCB ? Have you tried other batteries in the drill ?
Sounds like a mission that will not be cost effective in the long run.

 

[littlespark]

The drill is fine. There's 2 batteries in the box and one works perfectly. Other one just will not charge.
The fact that both read full voltage on a multimeter has me stumped.
That's why I think its a connection problem. Theres power there, just not getting through to the drill when plugged onto it

 

[pirate]

I hate retiring stuff...but sometimes it's the only way to go. Yes, you can get new batteries at a reasonable cost, but maybe it is time to wrench yourself away and take a new route? I hate it, myself...stuff going to waste, but usually after I take the jump, life is better!
Thus, you have a source of new batteries, but the cost of upgrading makes sense as you will be on a newer platform...
Took me 5 years to change from my trusty Ferm 24V bargain to the DeWalt Li=ion 18V, but I have to say the transformation was amazing.
Just my thoughts...

 

[littlespark]

Why would you???
Price comparison on one genuine DeWalt battery;-
Pirates link from post #2 ---> £49
Popular online store that's named after a river ---> £98
My local 3 letter electrical wholesalers ---> £129!!! and that's without VAT

My budget isn't going to stretch to a new kit this month, or next.
False economy, but I might just get a £20 non branded just now and see how it goes.

 

[Squid]

The drill is fine. There's 2 batteries in the box and one works perfectly. Other one just will not charge.
The fact that both read full voltage on a multimeter has me stumped.
That's why I think its a connection problem. Theres power there, just not getting through to the drill when plugged onto it

 

[Squid]

I tried the above on some standard Dewalt Battery 24V do a search on YT

 

[rolyberkin]

There was someone on another forum that had a generic replacement battery go up in smoke (not even on the charger!). Personally I would stick with genuine but shop around.