RonSmithJr
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Joined: Mon Sep 07, 2020 3:59 pm

Re: 12v Battery - All You Ever Wanted To Know

Sat Nov 21, 2020 1:46 pm

OK, I was able to determine that the 12V battery had died, and replacing it (back in Sept.) fixed the problem.
However now I seem to be having problems with the battery again. Is it possible the battery has gone dead again so soon?

Alternately I checked the fuse for the battery, a 30 amp fusible link. It looks odd to me, but I have not been able to find any picture anywhere of what the fuse looks like when it is undamaged, so I am not certain if the fuse is the problem. Anyone have a picture of a good 30 amp fusible link (Mitsubishi I-miev 2012) they can share?

eldenh
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Location: Port Angeles, WA

Re: 12v Battery - All You Ever Wanted To Know

Sun Nov 22, 2020 5:54 pm

The system uses a 120 amp fuse link on the right side of the positive connector to recharge the battery.
2012 ES

JoeS
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Re: 12v Battery - All You Ever Wanted To Know

Sun Nov 22, 2020 8:32 pm

RonSmithJr wrote:... Is it possible the battery has gone dead again so soon?...
Not so much dead (yet), but over-discharged. How often have you been using your i-MiEV?

I plug in a wall or solar float charger whenever I know I won't be using the car for even a couple of days, as it keeps the 12v battery from being cycled. Even a drop down to 12.20v means the 12v battery is down to 50%SoC. There is lots of information about lead-acid battery life vs. depth of discharge, all of which points to NOT wanting the battery to discharge much at all! For example, check out the DoD vs Cycle Life graph on this site: https://www.mpoweruk.com/life.htm
EVs: Two '12 Wht/Blu SE Prem., '13 TeslaMS85, three 156v CorbinSparrowsLi(NMC), 24v EcoScoot(LiFePO4)
EV Conversions: 156v '86 Ram PU, 144v '65 Saab96, 48v1kW bike
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RonSmithJr
Posts: 3
Joined: Mon Sep 07, 2020 3:59 pm

Re: 12v Battery - All You Ever Wanted To Know

Mon Nov 23, 2020 2:13 pm

I tested the battery and it is fine, i.e. fully charged.
The 30 amp fusible link I am talking about, that looks odd to me, is left of and below the steering wheel (practically on the floor).
What is it supposed to look like when it is good?

Adoepner
Posts: 79
Joined: Mon Jul 01, 2019 10:08 am

Re: 12v Battery - All You Ever Wanted To Know

Fri Feb 12, 2021 3:04 pm

I can confirm that a group 51r 12V battery will fit in the place of the OEM 151r. I could buy an AGM 51r for fractionally more than a FLA 151r. To get the 151r fit with reasonable clearances, I relocated the fuse/relay box that is beside the battery to the left (in a LHD NA model) by 1/2”.

jray3
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Location: Tacoma area, WA
Contact: Website

Re: 12v Battery - All You Ever Wanted To Know

Sat Jul 17, 2021 9:08 am

I don’t watch Transport Evolved often, but when I do it sometimes sparks a thought.
Nikki alleges that the lack of high starting/charging currents allows EV starting batteries to sulfate up and not break loose that sulfate through vigorous exercise. I’ll buy that theory and posit that the excellent service life of my original battery (preventative replacement after 6 years and 80k miles when OBC failed) was due not in spite of but possibly because of my frequent use of MR BEAN as the jumpstarter of a big diesel truck with parasitic loads. That little flooded battery saw maximum amps many times, but not deep cycling.
https://m.youtube.com/watch?v=pu30bchGu50
2012 i-SE "MR BEAN" 125,370 mi, 38 ah
2016 KIA SOUL EV, 90 kW, 72k miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh

CZeroOwner
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Location: Denmark

Re: 12v Battery - All You Ever Wanted To Know

Mon Jul 19, 2021 12:33 am

I believe I have found the PID with the current to the 12v battery charger. Using garygid's notation it is:

384:D4 = amps to the 12 volt battery charger on the high voltage side
384:D4 as D4/100 = amps @ about 360volts

I have included this in OBDZero at the end of the list in the OBD screen. I would really appreciated if someone could check if this is correct.

While I'm at it I am fairly sure I have found the ambient air temperature:

286:D4 = air temperature in oC
286:D4 as D4-50 = temperature in oC

This is also included in OBDZero as AirSensor on the OBD screen.

David

stoatwblr
Posts: 16
Joined: Tue Sep 28, 2021 12:17 pm

Re: 12v Battery - All You Ever Wanted To Know

Thu Sep 30, 2021 3:14 pm



Thread necromancy.....

Is there a writeup on how you ran the cabling back to that position by any chance?

The current (2021) crop of LiFePO4 batteries all seem to have internal BMSes in them so that's one less thng to worry about and I have a webasto I've had for a long time and want to mount in the battery position

stoatwblr
Posts: 16
Joined: Tue Sep 28, 2021 12:17 pm

Re: 12v Battery - All You Ever Wanted To Know

Thu Sep 30, 2021 3:17 pm

PV1 wrote:I still have only experienced battery memory on NiCd, but everyone seems to think that all batteries have memory


It's extremely harmful to store LiIon in deep discharged state (they occasionally ballon or even catch fire) or keep them float charged - they seem to prefer being stored at about 75-80%

NiMH don't like being continually floated or left discharged, but what kills 'em in short order is being reversed - which will burn LiIon

BMSes have come a long way in the last decade. They needed to

PV1
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Re: 12v Battery - All You Ever Wanted To Know

Sat Oct 02, 2021 11:33 am

Of course, each battery chemistry has different care practices, but only NiCD requires full cycles each time to avoid capacity loss. This is due to the physical crystal growth and dissolution that occurs when the battery is cycled.

While detrimental to calendar life, a lithium ion battery won’t lose a bunch of capacity to memory if it is shallow cycled a few times between 85-100% for example. Lead acid, on the other hand, keep it full and never use more than half of the capacity.

My electric toothbrush, though, has a design life of a year or two with its NiCD battery, which I’ve stretched out to a decade by not following their recommendation of leaving it charging on the base when not in use. I run it until it stops, and then charge it. Yes, it has replaceable heads.
"Bear" - 2012 Diamond White Pearl ES with QC
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"Photon" - 2017 Bolt EV LT in Orange with QC
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