Where to buy SI Batteries?

[Nakzter]

I did my DIY yesterday and just tapped wires on the terminals where the old batteries were. Went to radio shack and didnt have the batteries (The 23-1** and 23-149 - Not sure, dont remember). So I got a NiMh 2100mah.. It worked for 1 min then the tach needle dropped...

I'm thinking its the batteries, dont I need a NiCad? Please advise. Thinking about just replacing the whole board....

Thanks

[DaveSmed]

Did you check polarity? Batteries wired in series for 3v? (well, 2.4v if your picky, dern rechargables...)

[AndrewBird]

Doesn't matter weather the battery is NiMH or NiCad. MiMH batteries are actually better though because they do not build up "memory" and put out more punch then a NiCad (pointless in this situation).

Either the battery was in backwards and popped or your solder joints came loose. Batteries can be hard to solder sometimes. Did you rough up each end of the battery with a piece of sand paper before soldering?

[Griffin]

My tach behaves oddly sometimes, are the batteries really required for its operation? seems like a silly design to me!

[StereoInstaller1]

My tach behaves oddly sometimes, are the batteries really required for its operation? seems like a silly design to me!

I think some of the very last E30s off the line got the newer style of panel, but yeah, most all E30s have 2 AA batteries in their instrument panel.

[DaveSmed]

My tach behaves oddly sometimes, are the batteries really required for its operation? seems like a silly design to me!

It seems so, but in reality, the answer is no. The tach, econometer, speedometer, and fuel gauge will even operate with the SI board completely removed from the cluster. The problem is, old batteries do funny things electrically speaking, namely in the form of shorting out, leaking corrosive acid on sensitive circuit boards, etc. With the board tapped into all of the gauges, shorting all of them to, say, ground results in an inoperative cluster.

Now the temp gauge on the other hand.... I can't tell you why, but for all of the gauges I mentioned above, the Si board taps off the signal going to the gauge. For the temp gauge, the signal from the engine goes to the SI board first, then out to the gauge. If they had built that circuit like the other gauges, you could merely yank the offending board out and be done with it. As it is, many people opt to bypass the board with a wire connecting the temp sender and the temp gauge on the main board and that allows them to run without that board at all.

Another common misconception is that the third tang soldered on the batteries is necessary. It is there ONLY to mount the batteries securely to the board, and has no electrical connection at all. If you wanted, you could get some two conductor wire and solder it to the board, run the wire out of the cluster and have a small two AA battery holder under the dash somewhere.

[Jean]

My tach behaves oddly sometimes, are the batteries really required for its operation? seems like a silly design to me!

Since you have an early e30, you can bypass the SI board all together.

[funcrew]

...Now the temp gauge on the other hand.... I can't tell you why, but for all of the gauges I mentioned above, the Si board taps off the signal going to the gauge. For the temp gauge, the signal from the engine goes to the SI board first, then out to the gauge. ...As it is, many people opt to bypass the board with a wire connecting the temp sender and the temp gauge on the main board and that allows them to run without that board at all.

Anybody want to post up details on wiring the temp gauge directly like this? I mean dumbed down for guys like me.