SI board batteries

[gath]

How do you apply solder on to the SI batteries, I tried and the solder is not sticking at all, just sliding off. Solder is sticking onto the mounting plates but not the batteries.

[jeffnhiscars]

Make sure it's clean and that you are using resin core solder. I also find a little extra paste helps (depending on your solder size of course). A friend of mine is an acoustical engineer and he taught me a little trick that really helps...keep a small piece of wet rag handy and give the gun tip a quick wipe after pulling the trigger.

[george graves]

ok - super quick lesson on soldering.

Three things need to come together at the same time - within a second or two....

heat
solder
flux
(also a clean surface - but that's a given - and don't use flux that is made for house-hold copper pipes - or it will eat away at things)

Miss any one of them, and you'll have a bad time.

Also, with a PCB, you can only re-solder to it 2-3 times before it's going to separate it's copper layer from it's fr4 backing. No matter how expensive the product is. So learning how to solder before you need to is a *good thing*....

(ps - don't tell Luke I said this - but soldering is soooo easy! Buy a $25 iron, and practice on wires, your junk VCR, ect...It's not rocket surgery) Also - to support a fellow r3v member....

No affiliation....but GregM3 (Not his exact name - sorry I forget it) dose e30 cluster repair and refurbs for WAY, WAY less then he should charge - so look into that.

Here is his link. http://www.r3vlimited.com/board/showthread.php?t=247878


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[gath]

Interestingly, 'am using Rosin-core solder and the battery surface has been abrasively cleaned. Will look into the that George, and also give it another shot. Thanks.

[diamonddonbmw]

Greg Mannino. He did a great job on mine a couple of years ago, my '87 325is, that had 380,000 miles on it.

[jlevie]

I doubt that you will have any success with a rosin type flux on the ends of the batteries (it is the wrong metal for a rosin flux). An acid flux suitable for work with Stainless Steel will work. I have always had good success with Harris Stay-Clean flux.

[Gregs///M]

Thanks for the reference George G!

To the OP. Unless your batteries have the solder tabs already on, I would suggest you do forget trying to solder directly to the battery ends. It will take specialized equipment to get the solder to stick and last a long time. Poor solder joints will come off easily in a vibration environment (every e30)

However, with the solder tabs, it will take on solder very easily.

[gath]

Went to Batteries Plus store where I bought the batteries from and they tack welded the batteries to the solder tabs on the SI board, they do it free if you buy the batteries there which was very helpful.

[AndrewBird]

You likely aren't getting the battery hot enough. Batteries take a lot of wattage to get them hot enough. Keep in mind, you won't be able to solder lithium batteries. They will explode before getting hot enough. Ask me how I know.

Another option is to buy a 2AA cell battery holder from radio shack and wire that in. Then just tape/velcro it to the outside of the cluster. That way you can replace the batteries as needed.

[gath]

You likely aren't getting the battery hot enough. Batteries take a lot of wattage to get them hot enough. Keep in mind, you won't be able to solder lithium batteries. They will explode before getting hot enough. Ask me how I know.

Another option is to buy a 2AA cell battery holder from radio shack and wire that in. Then just tape/velcro it to the outside of the cluster. That way you can replace the batteries as needed.

The post above yours, thanks though.

[george graves]

Thanks for the reference George G!

To the OP. Unless your batteries have the solder tabs already on, I would suggest you do forget trying to solder directly to the battery ends. It will take specialized equipment to get the solder to stick and last a long time. Poor solder joints will come off easily in a vibration environment (every e30)

However, with the solder tabs, it will take on solder very easily.

Yea, battery tabs are "spot welded on" - you generally can't solder to battery. *if* you can get the solder to stick, it's usually can be broken off with a bit of force (or time and vibration)

I guess technically, you might be able to silver solder them - but that's a PITA.