Dead Sigmarion III battery

This actually happened months ago, but my Sigmarion III no longer holds a charge, it dies the second I disconnect the AC adapter.

It had started by switching from green to amber when left on the AC adapter, the battery would keep alternating between charging and charged.

Does anyone know how to rebuilt the Sig III battery or where to get another one?

Thanks


Edited by aab 2013-11-05 11:42 PM

Good timing - mine's dead too.

Get a pair of 18500 elements on eBay, remove the protective PCB if needed, balance the voltage, solder.

Nothing difficult at all. You will eventually need to do that anyways, Sigmation batteries were discontinued long time ago.

Edited by Alt Bass 2013-11-06 2:53 PM

Guys, does this strategy work in general? I have a Clio C-1050 with a dead battery pack (from 1999 so no surprise). Does anyone have experience with replacing the individual cells inside it? I'm not a stranger to soldering but the pack itself looks pretty sealed up and will likely not be trivial to open. Thoughts?

I once tried to break open a Mobilon battery but became extremely nervous I would damage myself rather than the tech, so I left it alone. If your battery isn't held together with glue or some adhesive you should be alright, but make sure you have the right tools on hand.

The cell packs are supposed to be protected in order to discourage you from trying to open them. If you try to get into it, you'll need to Stanley knife it open - VERY, VERY CAREFULLY.

Remember you are dealing with Lithium - low heat solder, don't wave the iron around.

To clarify something that you may misinterpret from Alt Bass's comment above. Never install the battery without some form of charge circuit connected: DO NOT connect the raw terminals to the DC lines without a protection circuit.

I cannot resist adding to this topic as I've rebuilt close to 40 HPC batteries...so I think I'm a pretty good amatuer expert here.

First...when taking apart the old battery, use the existing seams and score them with the sharp razor knife you use. C:Amie mentioned Stanley knife, and I've used Xacto knives...essentially the same...but the point here is you need to make repeated cuts and do so very slowly. Some batteries I've made over 100 scrapes/slices along the seams to finally separate them. You have to be patient and take your time. Try cutting too hard and you will surely cut through the casing right into the protection circuit and then you are doomed to fail. Plus slow cutting means a nice smooth score along the seams, making it very easy to reassemble the cell and reglue it afterwards.

Next...the protection circuit board. Handle it gently. Often the battery contacts are nothing more than conductive pieces of flat steel. They may not be soldered, but welded or pressure fit into the old LION battery. If possible, separate them at the battery, leaving the protection circuit untouched. While the cells die eventually, the protection circuit board rarely fails. But without it...you are doomed.

On that note, ever notice the contacts on a battery where it connects to the HPC? You will find numerous contacts, anywheres from 5-7 of them. This is because a set voltage runs to each cell to charge it independent of the other cell. And then you have to have a pair of power lines that encompass the whole battery, i.e. 7.4V for a pair of 18650s. This is normally unprotected. The HPC itself uses these individual lines to monitor the battery and give you that wonderful "low battery" warning you get when they wear down. If you were to pop in a pair of charged 18650 cells, they would run fine...until they ran down, but you would not be able to monitor the current voltage state, and probably would get that silly battery warning immediately depending on how your HPC was designed. Some HPCs have a set of contacts that solely monitor the battery state, while the main power lead is a heavier lead connecting elsewhere to the pcb on the HPC. Other HPCs simply monitor the power off the main power lead. The independent lines to each cell also provide a fixed voltage for recharging.

Next: Don't be afraid to take pictures! While you disassemble your battery, take pictures to show which way the connector sits in the casing, how the batteries line up, where the wires run, etc. When you get to a zillion parts...it can get confusing.

Be precise. Certainly one of the things most new battery builders do is find themselves without enough room to reinstall the new cells. Probably a little glop of solder isn't much, but when these batteriers are machine manufactured, their tolerance is in thousands of an inch, so you might find that 1/8" makes your battery too long to fit in the cell. This is where I love to use that conductive glue you see on eBay. it helps to make a contact a better contact if you are only pressure fitting your cells and not actually soldering them. These days I use QuickAlloy solder that you can find on eBay or anywhere else for my batteries...it melts around 140 degrees F, not like normal solder which may be 300 or more. But the nice thing about the QuickAlloy is you can mix it with normal solder to make it whatever melting point you want.

Lastly...after you get everything resoldered or fitting the way you want it...don't superglue it or epoxy it unless you have no other choice. I prefer to use back silicon rubber sealant as an adhesive, It will dry and hold the case together nicely, can very easily be trimmed if you use excess, and makes it simple to pull you battery apart the next time you need to rebuild.

These posts are tremendously helpful, thank you so much folks. All the detail is very much appreciated. I shall be careful, record my steps, take photos and if I am brave enough to go through with all this I shall report back my findings and any Clio-specific tips I can share. I have a spare battery pack so if I totally mess this up I will at least not be completely sunk.

One other thing...if you buy new 18650 cells, or whatever your HPC takes...don't be fooled by the high ratings you see on eBay. Those Ultrafire 4000mAh batteries you see advertised are just that...advertisement. Stick with a Sony, Panasonic, or Samsung in the 2600mAh range. They have a higher depletion rating and will end up being a better battery for your money than those others you see.

Advice noted. Thanks!