4ah high power battery repair

[Coen]

I was pretty stoked though cause I only had to boost the cell voltage a minute or two and got them working as good as new, so two free batteries in the end!

Except they are degraded. If you do the impedance and capacity test, you will see they will not be as new at all.

 

[surfjungle]

In previous post #2, I mentioned returning a battery to Festool service and they told me it needed to be replaced and they would dispose of it if I wanted them to. I declined their offer and paid them to return the battery to me thinking I could always re-cell the battery. myself. It's been sitting on the charger downstairs for the last 2-3 months and the charger light is always red. After reading the above @surfjungle post, I decided to try updating the battery because it was also at the V7 firmware level.

Well after updating the battery to V15, I'm now sitting on the couch upstairs monitoring the battery downstairs being charged from 44% to currently 59% 63% 65% and continuing to rise. I wonder why Festool told me the battery was bad and they didn't just upgrade the firmware?

Thanks for the post surfjungle...

My pleasure. I've found this forum to be very helpful. You experience vs mine points to inconsistency in the enablement and training of Festool reps.

 

[luvmytoolz]

Except they are degraded. If you do the impedance and capacity test, you will see they will not be as new at all.

Maybe but I dunno, the app reports 100% capacity, and over time the drop is no different to the brand new ones and they last as long in use according to the times recorded in the app. I've done the same with my Makita LXT's and 10-15 years later they're still going strong. If I get even close to 10 years ad-hoc usage I'll be very happy.

 

[PaulMarcel]

Ooh, excellent info, @surfjungle! I'm updating one of mine from V7 to V15. This pack seems to work okay, but of my 3, one never seems to charge. I put it on the charger to get enough charge to update it. Hoping it works cuz that battery is basically dead otherwise

Other interesting thing: after the update, it showed the current battery level. It started at 89%, updated, resumed at 76% then the percentage was dropping quickly and is now settled at 73%. Almost indicates that V7 wasn't tracking the charge correctly and thought it had more than was there. Each charge cycle would possibly add to the error.

 

[luvmytoolz]

I've got to admit the fact we can't run the Festool app in Australia is just bewildering. Like Paul's post above, I occasionally see people updating firmwares but we don't have that option at all. Very annoying, especially when we get reamed on the pricing like we do.

 

[Coen]

There are ways around that ..

 

[PaulMarcel]

With my one battery that would never connect for an update, on a whim, I tried the Festool app from an iPad Mini. It connected fine and did the upgrade. From the iPhone (XS Max), the BlueTooth connection would fail immediately. It's charging up now; eager to see how it works later as this battery was very troublesome.

 

[surfjungle]

I've got to admit the fact we can't run the Festool app in Australia is just bewildering. Like Paul's post above, I occasionally see people updating firmwares but we don't have that option at all. Very annoying, especially when we get reamed on the pricing like we do.

If the answer to some battery fixes is a firmware update and you can't do that, I'd push hard for a new battery or for the dealer / vendor to update it. From my perspective, this is not acceptable. There was a time when a battery was just that, a battery. Now it can fail due to bad software apparently. You can also cite other countries successfully using firmware via the app to resolve battery related issues such as in my case in the EU.

 

[surfjungle]

With my one battery that would never connect for an update, on a whim, I tried the Festool app from an iPad Mini. It connected fine and did the upgrade. From the iPhone (XS Max), the BlueTooth connection would fail immediately. It's charging up now; eager to see how it works later as this battery was very troublesome.

How did it turn out?

 

[PaulMarcel]

How did it turn out?

I don't have a really good test yet as there's some personal things going on. Next week, though, I'll put that battery in the CTC-SYS and run it until I get 3 warning beeps. Then I can compare the charge in both batteries to compare them. It is odd, though, that of the 3 4Ah batteries, 2 connect to either the iPhone or iPad, but that one will only connect to the iPad even after the update.

 

[luvmytoolz]

If the answer to some battery fixes is a firmware update and you can't do that, I'd push hard for a new battery or for the dealer / vendor to update it. From my perspective, this is not acceptable. There was a time when a battery was just that, a battery. Now it can fail due to bad software apparently. You can also cite other countries successfully using firmware via the app to resolve battery related issues such as in my case in the EU.

I'm actually not real clear on how the warranty works for the batteries, as they're an item you can't directly register for warranty. I had an issue with the batteries on a Mirka sander I bought coming DOA, the vendor replaced them straight away without any issue. I just hope if I do have an issue at some point I won't have a bad experience, as most vendors here treat batteries as a consumable that's not covered the same as the tool is under warranty.

 

[PaulMarcel]

I'm curious if the Aussies have tried a VPN to virtually be in the US for the firmware upgrade.

 

[surfjungle]

I'm actually not real clear on how the warranty works for the batteries, as they're an item you can't directly register for warranty. I had an issue with the batteries on a Mirka sander I bought coming DOA, the vendor replaced them straight away without any issue. I just hope if I do have an issue at some point I won't have a bad experience, as most vendors here treat batteries as a consumable that's not covered the same as the tool is under warranty.

The laws may vary from different regions yet some of this should be good faith too which what happened in my case. I had something low in the cycles before both batteries stopped and it looked terrible for Festool. Because they dealt with it so well, I'm still confident using them. However, as I said above, they're in danger of over-engineering the most basic of items and if one was being particularly skeptical, one might say that it's a form of planned obsolescence.