[time-nuts] What to do with a 5061A/5061B with dead NiCds

J. L. Trantham jltran at att.net
Sun Feb 5 20:04:41 EST 2017


I've rebuilt the NiCd battery packs with tabbed half D NiCd cells that are about $5 each (with tabs, shipped) and it takes 20 of them and some time to disassemble the pack and solder the new cells together.  They will eventually die and you will have to replace them again.  The half D NiMH cells I've seen have a larger capacity and noticeable more expensive.

I think I would choose to use an external 24 V battery with an attached battery charger as the backup rather than a UPS.  Batteries would be cheaper than NiCd's but more 'clumsy' to move and keep the unit powered.

The HP 5085A and HP 5089A were designed to take two 12 V SLA batteries and supply the needed charging circuitry and connectors to connect to the unit as a backup.  It could be mounted in a common cabinet with the 5061A or B as a 'movable' (not really 'portable') unit.  I have a 5085A that serves as backup to two 5061A's each with Opt 001 clocks.  The 5085A and 5089A don't show up often on theBay and their original batteries I have not been able to find.  I have made some minor modifications and was able to fit two Panasonic LC-X1228AP batteries in the unit.     


Choices 3 and 4 seem like a lot of work, particularly the Li Ion option.  

I like the idea of the built in NiCd pack in that you can easily (well, it's heavy) move the unit and keep it powered.

Good luck.


-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Skip Withrow
Sent: Sunday, February 05, 2017 5:27 PM
To: time-nuts
Subject: [time-nuts] What to do with a 5061A/5061B with dead NiCds

Hello time-nuts,

I have 5061A and 5061B units with the battery option and dead battery packs.  My question is what makes the most sense when refurbing these units?

1.  Yank the old battery out and just leave it that way.  Running the unit on a UPS would preserve the functionality.

2. Replace the pack with a rebuilt NiCd pack.  I'm sure Batteries Plus would be happy to do it, but sounds expensive.

3. Replace the pack with a NiMH pack, and really crank down the float current of the 5061.

4. Replace the pack with Li-ion battery.  Would be a much smaller battery, but the charging circuit would have to be pitched.  Building in a Li-ion charge controller sounds like it could be a project (which I don't necessarily want).

5. Yank the old battery pack and run the 5061 on two 12V batteries with an appropriate power supply/charger (basically a version of #1).

Any thoughts on these or other options would be appreciated.  Thanks in advance.

Skip Withrow
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