Cobalt 1 help: What to do if your battery is dead

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RonR

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An update on my situation: After charging to 100%, I left on a trip. Seems I sealed the battery compartment well enough! So exactly 1 week later and including 2 35 min. dives & prob. 10 min. review of the log, I was down to 56%. I charged to 100% again. 1 week later it was down to 70%, and after 2 weeks it was down to 36%, so it seems to lose 4%-5% of charge per day. My only complaint with this computer had been the short amount of time it would last on standby (about 2 months tops when new). Now even shorter but at least I was able to get it working.
Thank you RonR.
Happy that things worked well on your trip. It does seem as if this particular unit is using a little more current than would be normal. The reason why isn't something we can diagnose remotely. Other than needing to charge more frequently it doesn't seem to be causing a problem, but if you would like us to take a look at the Cobalt let us know. Cobalt 1's should last more like 5-6 months on standby if fully charged.
-Ron
 
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Happy that things worked well on your trip. It does seem as if this particular unit is using a little more current than would be normal. The reason why isn't something we can diagnose remotely. Other than needing to charge more frequently it doesn't seem to be causing a problem, but if you would like us to take a look at the Cobalt let us know. Cobalt 1's should last more like 5-6 months on standby if fully charged.
-Ron
 
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Team any idea on a replacement battery? Mine is completely flat. I love Atomic but 150 USD for a battery is overpriced. Looks like the original battery manufacturer no longer makes them. Anyone have a cross reference? I don't mind a little soldering.
 

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RonR

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Team any idea on a replacement battery? Mine is completely flat. I love Atomic but 150 USD for a battery is overpriced. Looks like the original battery manufacturer no longer makes them. Anyone have a cross reference? I don't mind a little soldering.
The battery has a custom connector, the batteries themselves have come from a variety of sources over the years. They do need to be the right specification to work with the charging circuitry. I'll message you with some suggestions.
-Ron
 

Ocean Child

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Hello Ron,
I have been reading through the forum on Cobalt battery issues and have found a lot of great information to help resolve my Cobalt battery issue. Seems from testing my PCB board is faulty or dead, when plugged in I get status battery charged but it shows 0% so i opened it up and the battery has 3.5 volts before the PCB but nothing after. To verify it wasnt my Cobalt I pulled the battery from my second one and put it in and it shows as expected battery 95% and if plugged in shows charging. so I am pretty sure it is the PCB that is faulty. now the fun part is I cannot find that model of battery as it seems it is no longer produced so since my battery appears to be good I thought I would replace the PCB (not worried about soldering built various battery packs before) but I am not sure of the specs - there are three wires P+ P- and the middle which I think is for Thermistor - is that correct? or do you know of an alternate replacement battery I can get and just solder the connector on?
any help is greatly appreciated.
Thanks Mike
 

RonR

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Hi Mike,

I think what I understand is that when you are referring to the PCB you mean the small PCB attached directly to the battery, is this correct? If so, have you determined that the wire connections are intact to the small connector with the three sockets?

The batteries for the Cobalt are a semi-custom part, as you correctly guess the third (blue) wire is for a thermistor to cut off charging when out of temperature range. The middle wire is ground. The charging circuity in the Cobalt is set to this specific battery, and looks at the thermistor reading as well as having in firmware the charging profile for the specific battery.

3.5 volts is very low, nearly dead, so I suspect that the battery itself may be failing- or not getting charged. The solution is likely a new battery. You don't say how old this Cobalt is, but we are starting to see some batteries reaching the end of their service life in older units. I'll send you a message with some suggestions.

Ron
 

Ocean Child

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Thanks for the reply Ron and yes I am refering to the board attached to the battery. I checked the wires and they are solidly attached. this is an older Cobalt 1. do you know the rating for the thermistor the sytem expects?
 

jimpeachey

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I have a Cobalt 1 and need to remove the battery to reset the charging circuit. Are the screws a special kind? They seem to be allen screws but i cant find an allen key the right size; everything is either just too big or just too small. Any help would be very much appreciated, also where can i get a new battery if this reset doesnt work?
 

RonR

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I have a Cobalt 1 and need to remove the battery to reset the charging circuit. Are the screws a special kind? They seem to be allen screws but i cant find an allen key the right size; everything is either just too big or just too small. Any help would be very much appreciated, also where can i get a new battery if this reset doesnt work?

Hi Jim,
They fit a 3/32" allen key, but a T-9 Torx driver will also work.

Here is al link to an instruction sheet that was put together for removing and replacing the battery:
Dropbox - BatteryReplace.pdf - Simplify your life

Let me know if you believe the battery itself is bad and I will try to get you connected with a replacement.

Good luck,

Ron
 
https://www.shearwater.com/products/teric/

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