So over the yrs I noticed that batteries didn't last long in kassandra.
- 1st gel battery lasted 2011-2013.
- 2nd gel battery lasted 2013-2019 (often requiring a jump starter pack).
- Switched back to a normal lead acid in 2019.
- Failed to hold charge in Feb 2021 so I replaced the battery under warranty.
- Even that one's been struggling to hold charge in Nov 2021 and out of warranty, so I brought another one
Something not right here ?
Strangely, I fully trickle charged both the previously faulty batteries overnight till they're 12.9v and they're able to hold 12.75v for days only dropping upto 0.05v per day, so the battery ain't the issue.
Tested the parasitic draw of the car to see if anything is draining the battery overnight, nope it draws an acceptable 10mA.
In this 1993 1.3 SLX, all the electronics were swapped over from my previous 1998 CG13 5dr SLX.
It had a various mish-mash of preface & facelift parts but oddly uses a simple 2-pole alternator
(thick white/red cable for charging, thin yellow/red wire for warning light, -ve grounding via the casing/engine block/earth straps)
Whereas most other micra's I've seen use a thick white/red charging cable and a multi-pin connector (for regulator sensing wire & warning lights)
According to the service manual, my charging system is from a LHD diesel engine? ??
Did a voltage drop test and this is where I found the possible issue.
The alternator itself outputs a strong constant 14.3v
Meanwhile at the battery it only receives 13.8v with nothing powered, 12.9v with all electronics turned on (barely enough to charge it)
Checking voltage drop from alternator to battery terminal was an insane 1.3v (normally should be 0.3v max).
I attached jumper cables from alternator to the battery to bypass the faulty alternator cable and immediately the battery receives 14.1v (nothing on), 13.8v (everything on), and voltage drop improved back to 0.3v ?
So the charging wire is where all the electricity's been wasted all these yrs! ?
This is further verified by recalling back in 2015 where I noticed the charging wire was already badly oxidised whilst I crimped a replacement section onto the ends.
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-131#post-720325
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-136#post-725519
So it definately needs replacing with a spare loom or ideally remake with fresh wires/connectors soon