Mac Portable - Replacement Battery Cells

[pintodave]

So with all of the work I have done with my Portable this year I have been back and forth from the local batteries Plus to get cells at least twice, but more times for other projects. I have found and researched a few different types of lead acid cells and/or cell packs that will work with the Portable.

Cyclone has a three cell Sealed lead acid (SLA) battery pack. 6v 5.0ah, as the original battery is, however these packs are notthree individual metal cases, they come in a single plastic casing, but otherwise are the same as the original Portable battery. With some trimming of the case, they can be fitted inside the Portable's original plastics battery casing and the contact tabs cut from the original cells and modified to connect to the new Cyclone pack terminals. I have seen this pack range from $27.99 to $35.99 at batteries plus.

There are also several different companies who develop SLA battery packs for commercial emergency lighting (the dual spot light type), and those cells are commonly 6v 4.5ah from what I have seen in the restaurants I do electrical for. I have prices these on the web, and they range from $9.99 to $17.99 depending on the brand and supplier. Note that these types of batteries are not rated to last as long as the Portable's original 5.0ah battery, however that are much more affordable. Their smaller size also makes it easier to fit inside the original plastic casing of the Portable's battery.

Durracell is also now making a 6v 5ah SLA battery, identical in output specs to the Portable's original ratings, but nearly the same sue as the 4.5ah security light cell. I am not sure how well it performs or how Manu charge and discharge cycles it will take, but the gentalman at Batteries Plus said it was comparable to the cyclone brand cell of the same rating. Not only is the Durracell smaller, but also lighter and cheaper, costing only $21.98.

Feel free to reply with input or info regarding these or other replacement options!

 

[uniserver]

http://www.batteriesplus.com/product_search/32650-Werker-6V-5AH-AGM-Battery-W_--dot187-Terminal-DASH--DASH-WKA6--5F.aspx

I like this battery $11.99 if you open an account with them, 

pretty sure they will open up an account for anyone.

IF you switch over to a SCSI2SD or Floppy Emu with your portable

your energy consumption is going to be way way less anyways.

if your board is killing batteries in one or 2 days, you might want to have techknight look at your board.

he has a whole system of going through these boards.

 

[techknight]

If you have a RAM disk setup, it will eat batteries.

 

[uniserver]

how much battery does your new Ram Card chew up Mike?

 

[techknight]

I dunno. Not much unless you have a RAM disk setup. Then its dead in a week.

 

[uniserver]

do you think you could make a ROM board for the portable?  maybe have a 6.0.8 install in rom?  

 

[pintodave]

Uniserver, the battery you posted is 19.99 on sale here in Boise, Idaho. I don't have an account with them yet but I may be opening one soon due to work needs. We have APC Smart UPS 2200 units which use four 12v 18ah SLA batteries, and the cost adds up quickly throughout the 22 locations they are dying in.

I must admit, I went through two of the expensive cyclone packs before I realized the mosfet for the battery charging circuit was bad. I still have a battery that is weak, but the board works as it should now. Surprising since it looks like it was found in a dumpster due to my early attempts at repair when I first got it!

 

[uniserver]

here we are 9.99 ebay, free shipping

http://www.ebay.com/itm/UPG-6V-5AH-UB645-Replacement-for-UPS-Battery-for-APC-AP200-/191402741759?pt=US_Rechargeable_Batteries&hash=item2c907e0fff

 

[techknight]

ROM boards are easy. Hacking the ROM to do whatever, is NOT my forte.. According to the developer guide, the ROM natively supports E-Disks, similar to what bbraun/dougg3 does with the ROM disks except its native and doesnt need hacking. 

But how to implement, no idea. 

 

[uniserver]

lol i wonder if i should send my portable to Rob

 

[trag]

how much battery does your new Ram Card chew up Mike?

This question caused me to go back and look at a couple of things.   The Datasheet for the SRAM chips (four of them per RAM card) says that it uses 9mW/MHz, which doesn't make a lot of sense, because the RAM is asynchronous (no clock pin).   So what exactly does "MHz" mean in this context?

If all four RAM chips were running continuously and the MHz value is 16 MHz, then that would be a noticable power draw.  .009 X 4 X 16 = .576 Watts. 

However, the datasheet also says:

It is automatically placed in low-power mode at 0.9 μA standby current (at VDD = 3 V, Ta = 25°C, typical) when chip enable (CE1 ) is asserted

high or (CE2) is asserted low.

So I went and looked at Techknight's schematics in the Designing a Portable RAM Card thread.   He controls the four SRAM chips using the CE1 pin.   So any time a specific RAM chip is not actually being accessed, CE1 is high, the memory chip is in low-power mode, and it only uses .000009 Amps X 3.3V = .0000297 watts per SRAM chip.

Soooo, with the RAM disk active, that should be just .0000297 watts X 4 chips X (1 week) = .0001188 watts X 168 hours = .02 watt-hours.   Hmmm.   Which at 6V (12V?) is even less amp-hours.    Either .00333 or .00167 amp-hours for a week in standby.

Having the RAM disk active should not be draining the battery in a week, unless having the RAM disk active means that the CPU is also still running, or some such.

Or let me rephrase.   The RAM card just doesn't use any power to speak of.   Why would leaving a RAM disk active drain the battery faster?

TechKnight did you test that in a backlit or non-backlit model?   I'm thinking the one with Pseudo-Static RAM might be trying to perform some kind of Refresh operation periodically.   I don't think that the buffer chips draw much power.

 

[unity]

I never understood the battery replacement "confusion" on the Portable. The original three-cell style is still available and fits right in. Only modification is to solder teh gold contact plates on the new battery. So easy a caveman can do it!

To open the battery, I *think* I used finger nail polish remover and applied it to the glued edge. But first I ran an exacto knife around. This helped expose the glue to the solvent. After a few minutes I ran the knife again, applied more solvent. When I was done, and with it glue back on, there was not a single sign of having it open.

 

[techknight]

This question caused me to go back and look at a couple of things.   The Datasheet for the SRAM chips (four of them per RAM card) says that it uses 9mW/MHz, which doesn't make a lot of sense, because the RAM is asynchronous (no clock pin).   So what exactly does "MHz" mean in this context?

If all four RAM chips were running continuously and the MHz value is 16 MHz, then that would be a noticable power draw.  .009 X 4 X 16 = .576 Watts. 

However, the datasheet also says:

So I went and looked at Techknight's schematics in the Designing a Portable RAM Card thread.   He controls the four SRAM chips using the CE1 pin.   So any time a specific RAM chip is not actually being accessed, CE1 is high, the memory chip is in low-power mode, and it only uses .000009 Amps X 3.3V = .0000297 watts per SRAM chip.

Soooo, with the RAM disk active, that should be just .0000297 watts X 4 chips X (1 week) = .0001188 watts X 168 hours = .02 watt-hours.   Hmmm.   Which at 6V (12V?) is even less amp-hours.    Either .00333 or .00167 amp-hours for a week in standby.

Having the RAM disk active should not be draining the battery in a week, unless having the RAM disk active means that the CPU is also still running, or some such.

Or let me rephrase.   The RAM card just doesn't use any power to speak of.   Why would leaving a RAM disk active drain the battery faster?

TechKnight did you test that in a backlit or non-backlit model?   I'm thinking the one with Pseudo-Static RAM might be trying to perform some kind of Refresh operation periodically.   I don't think that the buffer chips draw much power.

non backlit. I think RAM disks are turning on other stuff and drawing the battery, I dont know. 

 

[pintodave]

techknight - The RAM card arrived today, thank you very much!

I can do some testing as far as battery life goes if I get the time to play with the Portable this month!