What are the best batteries for Alesis Q2 and Q20

[sheendigs]

Hi Charlie
I was looking for the best battery that can be used for the Alesis Q2 and I came upon what follows...Could you comment on that..It will be a good source for those looking to replace their batteries..Sheendigs


Here's some info on battery life/change - the first one is from Alesis, the second was posted on the other boards:
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The Lithium battery should last about 7 years. Yes, the battery must be soldered. We do not recommend replacing the battery while the unit is connected to AC. Instead, back up the programs to a computer using MIDI, then reload them after you have replaced the battery.
Steve Taylor, Alesis Product Support
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There are no outwardly visible signs of impending battery demise - when the internal lithium battery voltage falls below 2.7V, the user patches will be lost and the display will show "garbage" information. It is possible to predict this by measuring the battery voltage, but his involves opening the unit and maesuring in the right place.
Battery life is determine by the type of static Ram chip used in your particular Q2 unit. Ram manufactured by Winbond unfortunately consumes 2-3 times more power that some SEC or other Korean manufactured chips, with the consequence that battery life will be correspondingly shorter. Typically I expect to get 2-3 years battery life from a Q2 with Winbond ram, but five or more years with other less power hungry ram.
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If you don't have the possibility to dump the userpatched using MIDI - and reload after battery change - another possibility was also posted here:
Buy 2 new battery cells (they are cheap), solder some leads on one of them and connect it across the print where the original cell is, take out the original cell. So the cell you have tagged in now holds the memory. Solder the second cell onto the print where you removed the original cell, then remove the cell on the wires.
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FYI - I went against Alesis' recommendations once and replaced the cell in my own Q2 (no EFTP) with the the PSU connected. I only did it after consulting another source/expert about the risks - and it caused no problems

[bill]

Hi Sheendigs,
Useful post. See also previous thread -
charliehall.proboards.com/index.cgi?board=technical&action=display&thread=1183

[Charlie Hall]

With Winbond memory chips, the battery life depends on the programs installed in the User banks. The battery in my Q2 (Winbond chips were installed from new) lasted for 13 months from the manufacture date.
With other chips, the battery life should be longer than 7 years, in some cases up to 20 years.
I do not recommend putting another battery alongside the original while it is being changed. A safer way is to use a resistor and diode along with the second battery. I have a file that explains it more fully.
I was told by Sound Technology that one way to change the battery on a Q2 is to have the power switched on and use a soldering iron without an earth (ground) connection. I have not tried this as I don't like the idea of using any mains powered equipment without an earth connection if it was designed to use one.
Regards,
Charlie