HP E4433B Lithium Battery longevity? - Page 1
Forum section: electronics / testgear

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 15, 2015, 03:45:35 am
content: Got myself a 1998 HP E4433B RF gen. Inside is a Panasonic BR-2/3A Lithium battery to keep memory and what not -http://industrial.panasonic.com/ww/products/batteries/primary-batteries/lithium-batteries/cylindrical-type-lithium-batteries-br-series/BR-2%252F3A. It currently measures 3.2V. How long do these things last? Panasonic's datasheets don't say much... And does it render the instrument useless when it dies (i.e. should I plan changing it)? Appreciate your help...

author: deadlylover
author_rank: Frequent Contributor
timestamp: October 15, 2015, 04:37:07 am
content: It depends on the particular instrument, see if the manual has anything to say about it. It could be storing something as simple as user configuration and the time or something critical like calibration data.Make sure you change it soon! You can't really tell the life it has left from the voltage because their discharge curves are as flat as a chopping board.I think the rule of thumb was to expect a 10 year life out of them, anything more is just gravy. I had one explode in a power supply a while back taking out quite a bit with it, I remember measuring it at 3.25V or so the week before it blew. It was around 15 years old IIRC.

author: cidcorp
author_rank: Unknown
timestamp: October 15, 2015, 05:21:53 am
content: I'm in a similar boat with a HP3468A on my bench. I've been trying to avoid making the change cause I didn't have the time. But I have heardstories of these Batteries dropping like a rock when they reach their 'time' - I'd say based on the age of the piece of equipment it reached it a long timeago.I've decided to mount a separate board with a socket for a DL123 3v Lithium because the Panasonic BR 2/3A isn't easy to source for me in Canada. Manydistributors will ship only inside the US. I also had to source a Butane soldering iron (which I didn't own until a week ago) to avoid any Ground Tip (Soldering Iron) issues,shorting the RAM and losing my Cal Values isn't something I want happening, and I'll have to do this all with Mains Power On. Actually not looking forward to it...Hopefully this weekend I'll pull the trigger.Good luck on your end, and don't get any confidence on the Battery voltage - they have strange characteristics and generally don't show any signs right before failure.Chris

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 15, 2015, 05:25:59 pm
content: Thanks for replying guys. A new battery is in order...QuoteWhy do you have to have the mains on?

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 16, 2015, 05:03:42 am
content: Quote from: ivaylo on October 15, 2015, 05:25:59 pmI think it's because the memory is volatile and will vanish if power is lost...

author: bingo600
author_rank: Super Contributor
timestamp: October 16, 2015, 12:26:01 pm
content: I wonder if the Cal values are in that NV-Ram, i hope they stopped uning NV_Ram for that when they build the E44xx Series.I have a E4432B , and would like to know.Agilent doesn't store the Cal values for the 34401A in NV-Ram , only the older DMM's.I hope they switched to eeproms for Cal values when doing the DSG's also./Bingo

author: rdl
author_rank: Super Contributor
timestamp: October 16, 2015, 02:16:00 pm
content: I have a Red Lion Controls digital hour-meter in my junk box, bought for a project in the 80s and never used. It runs off a "non-replaceable 10 year lithium battery". Last time I looked, a couple of years ago, it was still running...

author: G0HZU
author_rank: Super Contributor
timestamp: October 16, 2015, 02:35:24 pm
content: I can at least match this...When I finished my exams in the mid 1980s I bought a brand new Trio TS430S HF transceiver as some much deserved 'retail therapy' and I believe that it has a big coin cell battery in it to back up the user memories.But I have never ever changed this battery and the radio still holds my favourite memory frequency data to this day (just checked it)So that must be 30 years!

author: MarkL
author_rank: Unknown
timestamp: October 16, 2015, 04:17:26 pm
content: The E4400 series service manual is here:http://literature.cdn.keysight.com/litweb/pdf/E4400-90335.pdfTo save you some time, it says:QuoteHowever, if you look at the "Post-Repair Procedure" for post replacement of the battery, the box for "DCFM Frequency Offset" is checked off in both the performance verification table and the calibration table.DCFM Offset is the only thing checked off, but it would imply that for some reason this is the only calibration constant stored in the battery NVRAM.The DCFM calibration looks pretty simple and just requires a frequency counter.Calibration guide:http://literature.cdn.keysight.com/litweb/pdf/E4400-90325.pdfI have a E4433B and hadn't noticed the battery. Thanks for pointing it out.

author: bingo600
author_rank: Super Contributor
timestamp: October 16, 2015, 08:20:34 pm
content: Thanx Mark/Bingo

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 17, 2015, 03:35:19 am
content: Yes, that did save time. Thanks, Mark!I did order a replacement, but let's see when I get inspired if it isn't urgent...

author: ivaylo
author_rank: Frequent Contributor
timestamp: November 02, 2015, 05:08:39 am
content: Replaced the battery and looks like I didn't mess up anything. The replacement was $7 with the cheapest shipping of $11 (damn you Digikey), still much cheaper then what Keisight quotes. Didn't find what the replacement procedure in the service manual is so had to improvise. Completely disconnected the instrument from power, soldered two wires to the battery traces (tiny traces, had to scratch the solder mask too...) and via a diode connected 3.0V from an insulated PSU. Then unsoldered the battery and replaced it. The only hickup was when I discovered that the old battery was glued to the board which wasn't visible from above. A pair of pliers helped but around all those tiny traces and elements it wasn't for the weak of heart. It seemed to me that HP didn't think that battery will ever be serviced...

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 02, 2015, 05:21:12 am
content: Good job, congratulations!