A-ha! Thanks Gary. Studying Brian's photos I see that wasn't originally
a rechargeable pack. My (8201a) pack has the 70K ohm resistor on the
"set" lines & Ni is bridged to positive. They could have easily used the
NEC charging method as it presents 8.4V to pin 5 of the connector (8201a).
Slow charging Ni-MH is a black art so I figured I'll do some experiments
to see how long it takes to fully recharge. I'll write a program which
saves elapsed time & leave the machine on continuously until it turns
off from low-power. By adjusting charging times, I'll figure out optimum
charge-time.
Philip
On 24/07/2020 5:37 pm, Gary Weber wrote:
They didn't. That tiny little battery pack with the external charging
jack was an "aftermarket" thing. I think it was installed by a
company that did VAR resales of 8300s into industrial label printing
applications.
By the way the 5-cell NiMH solution works really nice. Keeps the
voltage way up in the acceptable range throughout the discharge cycle.
I definitely recommend the solution Brian highlighted.
On Thu, Jul 23, 2020 at 10:32 PM Philip Avery <pav...@xtra.co.nz> wrote:
Why did NEC go with such a small battery for the PC-8300?
I've just rebuilt my PC-8201a pack and it had 4 x AA Ni-Cd's originally. I replaced
these with 4 x Eneloop AA's (2000mAh) & lowered the charging resistor value so
it will charge them in a reasonable time-frame, ie overnight.
Philip
On 24/07/2020 3:40 pm, Gary Weber wrote:
Brian,
Those are precisely the same batteries I've been using to build up refurbished
5-cell rechargeable packs for my machines also. They've been working very well.
I got my battery sets off of eBay and they arrived within 10 days or so. They
still sell them there so you'll be able to find 'em.
Gary
On Thu, Jul 23, 2020 at 8:34 PM Brian K. White <b.kenyo...@gmail.com> wrote:
My PC-8300 came with a rechargeable battery pack that had a tiny 60mah
battery originally, a 5 button cell nicd hot-glued in the middle, with a
couple diodes & a resistor and it's own barrel jack to charge the pack.
All corroded and dead of course.
I determined that you could fit 5 x 1/2AA nimh cells in the same case,
same voltage, same charger, and get 800mah instead of 60.
1/2AA is a size that exists, but is pretty hard to find.
I found this on Amazon, welded tabs already, and even sold in sets of 5,
exactly the number needed, perfect.
http://amazon.com/gp/product/B07ZNZ535F/
Not so perfect, it took over 4 months to arrive (March 17 to July 21).
But they did finally arrive, and the size worked out.
Everything fits, and it's easy to replicate the original wiring just
moved around.
https://photos.app.goo.gl/JRVp71Govw49PXaM6
--
bkw
