PRAM Battery Woes

[Academician]

Hey guys,

I've been trying to locate a nice cheap source to buy up some batteries for a recent haul of 2x Mac Plus and 2x LC550, all of which have dead or half-dead batteries that no longer allow the systems to boot.

I have contacted local stores but found that even though they carry the 3.6v 1/2AA batteries for the LC, they are expensive. None of these stores, unfortunately, carries the 4.5v alkaline #523 batteries for the Pluses.

I have located BatteryMart.com which seems to have a reasonable total cost, and I have scoured the internet for a better source but can't seem to find one.

I'm probably going to end up spending more on these 4 batteries than I even did on the computers themselves! :O

-Academician

 

[tomlee59]

There are a couple of alternatives.

One is to use a small NiCd pack, such as used for some cordless phones. Many of these are 3.6V, which seems to be enough to work in most Pluses. I see these everywhere for a buck or two around here.

Another option that I've wanted to try, but have not yet, is to mod the Plus to use a supercapacitor (order of a farad; just need a small number of other parts). Not quite the same as a battery, but it may hold charge for days or hopefully weeks, which might be satisfactory.

Both of these options are cheap cheap cheap, compared to getting the official replacement. As long as you don't mind the mods, these should do the trick.

 

[equill]

You could search eBay for the seller ronaldo101. I get 3.6-V half-AA lithium batteries for less than USD4 each by buying four at a time.

The best that I have done with Rayovac 840 4.5-V alkaline was USD20 for four from yukonmkt. Such is the scarcity of 523 equivalents that they are likely to run over USD25-30, but there is the Chinese Exell A21/A133, which also carries the other makers' numbers: 523, PX21, EN133A and PC133A.

de

 

[JDW]

I purchased one in the past from ARTMIX here in Japan. Works well. Cost is ¥990 (about US$8, plus shipping, of course).

 

[Gary_W]

I can second ebay seller Ronaldo101. Have purchased from them several times. Great price and quick shipping.

Gary

 

[The Macster]

The Mac Plus at least should be able to boot without a battery - mine's never had a working battery.

 

[wood_e]

I went to my local interstate batteries place and they had the 3.6v batteries for under $8

 

[MacJunky]

This is what I did in my Performa 580CD. 3x 1.5v AA http://img136.imageshack.us/img136/7843/10007962jv2.jpg

This can be pretty cheap when you can get 50 packs of alkaline AAs for $15-$20.

Though, you might want to use a proper holder/cage. Only reason I did not use one is that I did not have one around and it was not worth a trip into town.

With other Macs that take a short little 3.6v battery I have found that two AAs work well.

 

[JDW]

MacJunky, if you are willing to go that far to put a non-standard battery in, you might consider a Lithium next time. Lithium would last you probably 6-7 years, even if the power cord was yanked that whole time from the wall!

 

[Academician]

Still not entirely sure what I should do with this battery situation. These macs will boot without the battery, so I'll probably hold off until I have a little extra cash to grab them up.

MacJunky, interesting and quite a cheaper idea. I was wondering how you configured that up. By that I mean what leads are connected together, etc, and how. I'm not a big electrical buff lol :]

-Academician

 

[MacJunky]

MacJunky, if you are willing to go that far to put a non-standard battery in, you might consider a Lithium next time. Lithium would last you probably 6-7 years, even if the power cord was yanked that whole time from the wall!

What do you mean far? That was probably the least I could do as I did not have any more stock ones yet I did have lots of AAs around. I live outside a small town, I am not going to make a special trip in just to get a certain type of battery when another will work for what I need.

 

[JDW]

I think it's quite clear what I meant by "far" regardless of where you live. I was in no way bashing you, so please calm down. By "far" I mean to say "do something other than the thing most people do" or more clearly, "to do something other than put in a battery inside the battery comparment of your Mac."

Now, you explained that the reason you did the mod was because you live in an area where you cannot find a battery that will fit the battery compartment. That makes logical sense, but I suspect there are thousands of other Mac owners in your exact shoes who would never go "as far" as you have to mod the battery. Most people actually do possess the knowledge to make a battery pack like you do, but they come up with excuses for why they cannot (no time, "I'm not technically inclined," yada, yada).

So my point in my previous post was (and still is), if any of you wish to perform a fine battery mod, you can reap even longer battery life by using a Lithium. Clearly, MacJunky, I was not suggesting that you trash your current battery and go buy a Lithium. I was simply saying that at some point your pack will die and when it does you can consider a Lithium for longer life.

This battery back idea is a fine idea and I was in no way condemning it. MacJunky should not only be commended for the fine idea, but also for his excellent photo showing it!

I hope this is clear!

 

[macclassic]

At the thought of spending more for a battery than I did for the Plus I shaped a piece of wood to fit the battery compartment, screwed two contacts onto it made from a tin can, fastened this to a 3 x AA battery carrier and wired the contacts up.

The length of the dummy battery plus the contacts is 49.3mm.

See pics below.

http://picasaweb.google.com/bromptys/PramBatteryMod?authkey=st1AS30ZSn4

A bit redneck but it works, I will of course keep the battery compartment door.

 

[chris]

4.5v? Uhhh... could this cause problems?

 

[macclassic]

I had to check!

No, the original Plus battery is 4.5v.

 

[Mac128]

Does anybody search these forums before they post?

http://68kmla.org/forums/viewtopic.php?t=1566&highlight=plus+battery

http://68kmla.org/forums/viewtopic.php?t=1610&highlight=lc550+battery

 

[JDW]

Does anybody search these forums before they post

No. And it infuriates me when they don't. It has for years. But many people post in such a manner not simply because they are lazy (and they certainly are), but because they know some kind soul out there will reply to their post and possibly give them they answer they want without their having to do any extra work at all. In the animal kingdom, we have named such creatures "sloths" and "leeches."

With that said, this site tends to be better than others I post in. CubeOwner.com is about the worst. Dozens of posts each day by people who could easily find the answer in the clearly marked FAQ or by a quick search of the forums. There are other sites too, but I'll spare you.

Ah well... I'm sorry for the rant. Mac128's comment struck a chord in me for some reason today. But I admit my rant is not directly relevant to this thread and I'm sure I've upset some people in the process too. But if any good can come of it, I can only hope it will help to inspire new posters to Search before posting.

 

[Unknown_K]

The sad thing is plenty of knowledge gets lost every time the forums get reset, I still mine the original archive for information from time to time.

 

[Unknown_K]

The sad thing is plenty of knowledge gets lost every time the forums get reset, I still mine the original archive for information from time to time.