Parasitic draw??

The stock TR wiring arrangement has no current draw from the battery when the battery cutoff switch is opened (i.e., when the negative battery terminal is disconnected from the chassis), but the internal self-discharge isn't zero, and, IMO, an elderly, near EOL, battery might not have enough ooompf after only a couple~few months even if disconnected (and a deep discharge cycle doesn't help its health either). Can you confirm that the clock resets when you "reconnect" after using the battery disconnect switch? (It should if truly disconnected). Is this with a reasonably fresh battery or an aged one? Also, how long a period of disuse?

 

Battery and alternator were changed in june 2017 on this car so pretty new.
Battery tends to die after 3 weeks i wanna say of sitting


Sent from my iPhone using Tapatalk

 

If not put on tender after 3 weeks to a month u might need to jump it.


Sent from my iPhone using Tapatalk

 

ECU on a TR is a strong word lol


Sent from my iPhone using Tapatalk

 

No that will last much much longer)


Sent from my iPhone using Tapatalk

 

I don't disconnect the battery on my 87 TR unless over winter. It can sit with battery on for a month and starts no problem.

 

Correct, only the clock needs resetting on a TR (and your radio button programming if so equipped ).

I've measured mine at ~65 mA so three weeks is about 33 Amp-hours which is a pretty big chunk of the smallish stock TR Group 47-like battery's total capacity (plus I've seen figures like 5% per week self-discharge capacity loss per week for fresh lead-acid batteries). Of course, you might want to measure the current draw to confirm/deny if you have any modifications increasing the parasitic current draw. Also, please indicate what size battery that you are using (and you too, ago car nut, please) - I'm using a Group 34R battery.

 

Yeah I physically disconnect the negative battery cable when not in use and it'll start up fine after months of no use.

Sent from my Moto Z2 Play using Tapatalk

 

I read somewhere that there still could be voltage leakage across old switches like that. By physically separating the circuit that can't happen. I dunno whether the science is true, but from my own experience it is. By disconnecting at the switch my battery lasts a week or two. By physically removing the cable it has lasted at winter.

Sent from my Moto Z2 Play using Tapatalk

 

you may check if really all is disconnected. may be an aftermarket alarm is connected directly to the battery? or something else? otherwise you may replace the switch.

I once had this "main switch" problem on an other car. inside has been and aftermarket switch from HELLA. and even the switch was OFF after about 3 weeks the battery has been empty. so my customer charged the battery and wanted to drive to my garage. but he called me that the starter will not turn. even not with jumping. so I went to him was my trailor and wanted to pick up the car. but before I tested. sit in the car, turned the ignition on. all testlights are working. then wanted to start and nothing, not even a click from the starter and all light got off. so typcal sign of a down battery. then I wanted to turn the main switch to OFF and was surprised: it was already off. so I turned to ON and could start the engine without any problems. so you see that such a main switch also may fail and could give you much thinkings.

if the switch is ok then there is no difference between turn off or disconnecet the battery

 

Everstart 860 cold cranking amps at 32 deg. F. don't know group #, fits easy.

 

Then you should also be able to measure a difference in the parasitic current draw for the two conditions (and must have some modification or flaw in the cut-off switch).

 

My 89tr had an aftermarket amp installed prior to me owning the car. I noticed once that the amp was still on after I turned the disconnect switch off. Not sure why it was on and it only happened once or twice. It has a blue light on top of it that is barely noticeable when its daylight. I only noticed it was on because it was dark in the garage when I pulled in.

 

If I search on "Everstart 860" I get some indications that this is a large Deep Cycle Group 29 Marine Battery -- anything like that on the labeling?

 

This car had an amp too but it was dead so removed it.


Sent from my iPhone using Tapatalk

 

Sent from my iPhone using Tapatalk