sony head unit discharging battery
Printed From: the12volt.comForum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=137342
Printed Date: April 28, 2024 at 8:41 AM
Topic: sony head unit discharging battery
Posted By: efx26
Subject: sony head unit discharging battery
Date Posted: September 28, 2014 at 1:37 AM
Replies:
Posted By: oldspark
Date Posted: September 28, 2014 at 11:57 AM
Posted By: efx26
Date Posted: September 28, 2014 at 12:45 PM
Posted By: oldspark
Date Posted: September 28, 2014 at 2:18 PM
Posted By: efx26
Date Posted: September 28, 2014 at 2:54 PM
Posted By: oldspark
Date Posted: September 28, 2014 at 7:28 PM
Posted By: efx26
Date Posted: September 28, 2014 at 9:31 PM
Posted By: oldspark
Date Posted: September 28, 2014 at 10:02 PM
Posted By: efx26
Date Posted: September 28, 2014 at 10:43 PM
Posted By: oldspark
Date Posted: September 28, 2014 at 11:43 PM
AGMs are good but a lot of people think they are "better" than wet cells and that depends so much on the application.
AGMs are popular in vintage vehicles - those that are not used for months at a time (and have no parasitic drains) - where you can crank away after 12 months whereas a wet cell would be long dead.
AGMs give good current but they do not like doing it, hence why you are better off with a wetcell for cranking and audio etc unless the AGM is upsized (compared to the wet) else protected by a cap (eg, for BIG audio systems >~3kW) unless there are a few paralleled AGMs.
And whereas you can totally flatten a wet cell (like to 2V etc) and it may recover - especially if new - go below ~10.6V whilst discharging or say 11.5V - 12.0V open circuit on an AGM and thereafter its best success will be as a door stop.
From an electrical abuse POV (over voltage, over current, & delay to recharge) AGMs are far weaker than wet cells.
In my circles people retain wet cells for crankers and use AGMs as required for secondaries. Many use a wet cell in preference as a secondary for normal use if they can mount them conveniently - eg, in the engine bay. But if internal and non-vented, then AGM it is. And AGM for negative G-force drivers or long stayers.
If you are using your AGM as you cranker then I'm not surprised you aren't happy with it - especially if it has parasitic draws. Or if it's an Optima
.
An AGM as a secondary with a primary wetcell for cranking - with automated isolator of course - now that's a different proposition, and how it should be (again, unless the AGM is happy with the cranking current).
AGMs are popular in vintage vehicles - those that are not used for months at a time (and have no parasitic drains) - where you can crank away after 12 months whereas a wet cell would be long dead.
AGMs give good current but they do not like doing it, hence why you are better off with a wetcell for cranking and audio etc unless the AGM is upsized (compared to the wet) else protected by a cap (eg, for BIG audio systems >~3kW) unless there are a few paralleled AGMs.
And whereas you can totally flatten a wet cell (like to 2V etc) and it may recover - especially if new - go below ~10.6V whilst discharging or say 11.5V - 12.0V open circuit on an AGM and thereafter its best success will be as a door stop.
From an electrical abuse POV (over voltage, over current, & delay to recharge) AGMs are far weaker than wet cells.
In my circles people retain wet cells for crankers and use AGMs as required for secondaries. Many use a wet cell in preference as a secondary for normal use if they can mount them conveniently - eg, in the engine bay. But if internal and non-vented, then AGM it is. And AGM for negative G-force drivers or long stayers.
If you are using your AGM as you cranker then I'm not surprised you aren't happy with it - especially if it has parasitic draws. Or if it's an Optima
.
An AGM as a secondary with a primary wetcell for cranking - with automated isolator of course - now that's a different proposition, and how it should be (again, unless the AGM is happy with the cranking current).
Posted By: efx26
Date Posted: September 29, 2014 at 2:18 AM
Posted By: oldspark
Date Posted: September 29, 2014 at 3:44 AM
It sounds like you know your stuff too - or at least suspect correctly - I'm merely confirming it.
So did your car originally have a wet cell? For audio buffs etc wanting "audio" batteries, I usually suggest keeping the original wet cell main/cranker (even if perhaps upsizing it) and fitting an AGM close to the amp. After all, going to the trouble of getting an AGM for its lower internal resistance only to still have the cabling resistance to the amp... And then that AGMs do not like cranking currents etc. Plus the secondary AGM can be an emergency jump start battery. But if only one battery is possible, then I can understand using an AGM (even if it does lower peak SPL LOL).
You also said your AGM was vented (or did you mean the boot/trunk?). AGMs are considered "sealed" tho yes, they have a vent. That's where their original name is clearer - VRLA = Valve Regulated Lead Acid (or Valve Recombination Lead Acid) - where the valve is the vent but it requires pressure to operate; ie it does not let the hydrogen vent, it keeps it to be recombined when charging. The valve is only to prevent pressurised case explosions due to heat or excessive gassing (eg, charging >14.4V, or less if any cell has collapsed).
What I mean to say is that although your AGM is technically vented, it isn't. [
?? ]
AGMs are great in that you can leave them 12 months without a recharge. That's by spec for a fully charged battery; some are fine after 2 years. As to my mate that started his car for the first time in THREE years with the battery still connected... That was my "real" intro to AGMs - specifically a Gates 40AH as used by telcos. I had no doubt the car would start, but I laughed at the suggestion that the battery would have any juice whatsoever. I hate people that ignore my laughs and have the last laugh.
The recharge time for full wet cells is generally accepted as being 3 months.
Of course both assume full charge, and no discharge (parasitic draws), and healthy batteries. (Old batteries self discharge at higher rates.)
Usually "internal" batteries must be sealed by law (eg AGM), else in a sealed enclosure vented to the outside.
However many OEM vehicles have internal wet cells. Even tho the same safety issues apply, the fact that they are OEM and approved means "they" can have wet cell internals, BUT it does not mean WE can add an internal wet cell. (Some people have difficulty understanding such legalities.)
You may read some old threads herein about me and my 38AH Yuasa UPS AGM. Tho IMO is should never have suited my main battery & cranker application, it faired well.
That Yuasa UXH series is designed for heavy discharge UPS applications and they have a 10 year design life, but that does not mean it will last long if used often (to full or near full discharge at max currents). I got mine when it was replaced after 5 years (a standard preventative maintenance/service procedure for essential systems like UPS) and did not start using it until it was 10 years old (excluding some camping/solar trips).
I used it as the sole battery for about 3 years before deciding to save it for "real" applications and getting a new wetcell main battery.
I decided to use it as a main after my brother said he had been using his for years. The fool! - I only gave it to him for use as an emergency battery; I never expected it to last as a cranker. (I think he's still using it. It's at least 14 years old and he's been using it for at least 5 years.) But they were oldskool Yuasas - IMO Yuasa was always a quality battery, but whether that still applies since the Chloride(?) buy in...
One of my learnings was the typical "non exercised" capacity. I used it as a secondary battery for a fridge etc before using it as the main battery.
It had occasionally been charged and always seemed fine - ie, its full 12.7V etc. (Recharges were maybe every 12 months. Its OC voltage was never below ~12.5V.)
It had been fully charged before fitting for the fridge. I used an MW728 battery protector - a 10A cig-socket battery protector aka low voltage cutout which disconnects at 11.2V and reconnects (I think) at 12.5V - and I noted it was clicking...
What was happening... The OC battery voltage was ~12.7V. The MW728 would connect the ~4A cooler and the battery voltage dropped to 11.2V within ~15 seconds.
The 728 disconnected and battery voltage quickly returned and after the 728's turn-on delay - a requirement for all such circuits including "smart" etc battery isolators - of ~15 secs the cooler was reconnected and the cycle would repeat.
That is ridiculous for a healthy battery of that size. But as I suspected, it needed a good high-current run. Sure enough, a short 5-10 minute drive fixed the problem once and for all.
The lesson - sometimes chargers cannot give the same current that an alternator can provide. (It was an 8A charger which IMO should be fine...)
It also confirmed what we experienced people know - battery voltage does not indicate actual capacity, it merely indicates its %age of capacity - ie, 12.7V is full capacity even if that is a mere 5AH and not its new/rated 38AH.
Incidentally, tho I never formally capacity tested that AGM, a few years later I had to limp home with headlights and no alternator. It was a 1 hour country trip and a quick head calculation (based on an assumed 15A loading - no hi beams!) suggested it should last 2 hours if it was still healthy (ie, 80% or more of its initial or rated capacity).
I got home without trouble. In fact after ~15 minutes my dash voltmeter confirmed my assumed loading (or rather, predicted battery voltage) was pretty good and I'd get home easily PROVIDED the battery didn't suddenly die. (A battery, especially old, may seem to discharge fine and then suddenly collapse without warning.)
The next day my DMM confirmed it was about 50% discharged which meant it was as good as new despite its 13 year age (3 years beyond its "design" life & 8 years after it was scrapped for UPS reliability reasons).
Ok, that was a lot of ramble, but FWIW.
You don't have an Optima. IMO that's good. IMO they were once good batteries but they took a dive a decade or 2 ago. Some still swear by them, but I know of too many failures.
My battery supply Guru stopped stocking Optimas ages ago - and disappointingly Odyssey which I held in high non-practical regard - due to high return rates etc.
He recommends Deka which I read are well regarded stateside as well.
Also IMO Kinetik get god reviews stateside.
FYI - I found out my UXH38-12 retailed for AUD$670
but the UXH100 (or UXH110?) retailed for $500. So 2.5 times the capacity and 25% cheaper. And if the 38AH handled my starter, a 100AH would romp it in. (My starter was 240A until I changed to a 140A reduction starter.)
With ~70AH Optimas retailing for $450 (maybe $350 in practice) I had no doubt which battery I'd choose - ie, the Yuasa UXH100-12. I'd be surprised if that did not last at least 20 years.
However since then a Guru-recommended dual-terminal ~110AH wetcell for $220 so that'll be my eventual camper & remote choice. (Main battery, maybe a 2nd in the engine bay AND/else another under the vehicle.) Apparently they are great as crankers for 4WDs, and for winching, and as deep cycle solars. That is unusual in that batteries are either crankers (high current) else deep cycles (low & slow current) by physical design, or a compromise between the two. Maybe it's a deep cycle but being so big (as for big AGMs) high currents are not such a big deal.
Geez I ramble!
So did your car originally have a wet cell? For audio buffs etc wanting "audio" batteries, I usually suggest keeping the original wet cell main/cranker (even if perhaps upsizing it) and fitting an AGM close to the amp. After all, going to the trouble of getting an AGM for its lower internal resistance only to still have the cabling resistance to the amp... And then that AGMs do not like cranking currents etc. Plus the secondary AGM can be an emergency jump start battery. But if only one battery is possible, then I can understand using an AGM (even if it does lower peak SPL LOL).
You also said your AGM was vented (or did you mean the boot/trunk?). AGMs are considered "sealed" tho yes, they have a vent. That's where their original name is clearer - VRLA = Valve Regulated Lead Acid (or Valve Recombination Lead Acid) - where the valve is the vent but it requires pressure to operate; ie it does not let the hydrogen vent, it keeps it to be recombined when charging. The valve is only to prevent pressurised case explosions due to heat or excessive gassing (eg, charging >14.4V, or less if any cell has collapsed).
What I mean to say is that although your AGM is technically vented, it isn't. [
?? ]
AGMs are great in that you can leave them 12 months without a recharge. That's by spec for a fully charged battery; some are fine after 2 years. As to my mate that started his car for the first time in THREE years with the battery still connected... That was my "real" intro to AGMs - specifically a Gates 40AH as used by telcos. I had no doubt the car would start, but I laughed at the suggestion that the battery would have any juice whatsoever. I hate people that ignore my laughs and have the last laugh.
The recharge time for full wet cells is generally accepted as being 3 months.
Of course both assume full charge, and no discharge (parasitic draws), and healthy batteries. (Old batteries self discharge at higher rates.)
Usually "internal" batteries must be sealed by law (eg AGM), else in a sealed enclosure vented to the outside.
However many OEM vehicles have internal wet cells. Even tho the same safety issues apply, the fact that they are OEM and approved means "they" can have wet cell internals, BUT it does not mean WE can add an internal wet cell. (Some people have difficulty understanding such legalities.)
You may read some old threads herein about me and my 38AH Yuasa UPS AGM. Tho IMO is should never have suited my main battery & cranker application, it faired well.
That Yuasa UXH series is designed for heavy discharge UPS applications and they have a 10 year design life, but that does not mean it will last long if used often (to full or near full discharge at max currents). I got mine when it was replaced after 5 years (a standard preventative maintenance/service procedure for essential systems like UPS) and did not start using it until it was 10 years old (excluding some camping/solar trips).
I used it as the sole battery for about 3 years before deciding to save it for "real" applications and getting a new wetcell main battery.
I decided to use it as a main after my brother said he had been using his for years. The fool! - I only gave it to him for use as an emergency battery; I never expected it to last as a cranker. (I think he's still using it. It's at least 14 years old and he's been using it for at least 5 years.) But they were oldskool Yuasas - IMO Yuasa was always a quality battery, but whether that still applies since the Chloride(?) buy in...
One of my learnings was the typical "non exercised" capacity. I used it as a secondary battery for a fridge etc before using it as the main battery.
It had occasionally been charged and always seemed fine - ie, its full 12.7V etc. (Recharges were maybe every 12 months. Its OC voltage was never below ~12.5V.)
It had been fully charged before fitting for the fridge. I used an MW728 battery protector - a 10A cig-socket battery protector aka low voltage cutout which disconnects at 11.2V and reconnects (I think) at 12.5V - and I noted it was clicking...
What was happening... The OC battery voltage was ~12.7V. The MW728 would connect the ~4A cooler and the battery voltage dropped to 11.2V within ~15 seconds.
The 728 disconnected and battery voltage quickly returned and after the 728's turn-on delay - a requirement for all such circuits including "smart" etc battery isolators - of ~15 secs the cooler was reconnected and the cycle would repeat.
That is ridiculous for a healthy battery of that size. But as I suspected, it needed a good high-current run. Sure enough, a short 5-10 minute drive fixed the problem once and for all.
The lesson - sometimes chargers cannot give the same current that an alternator can provide. (It was an 8A charger which IMO should be fine...)
It also confirmed what we experienced people know - battery voltage does not indicate actual capacity, it merely indicates its %age of capacity - ie, 12.7V is full capacity even if that is a mere 5AH and not its new/rated 38AH.
Incidentally, tho I never formally capacity tested that AGM, a few years later I had to limp home with headlights and no alternator. It was a 1 hour country trip and a quick head calculation (based on an assumed 15A loading - no hi beams!) suggested it should last 2 hours if it was still healthy (ie, 80% or more of its initial or rated capacity).
I got home without trouble. In fact after ~15 minutes my dash voltmeter confirmed my assumed loading (or rather, predicted battery voltage) was pretty good and I'd get home easily PROVIDED the battery didn't suddenly die. (A battery, especially old, may seem to discharge fine and then suddenly collapse without warning.)
The next day my DMM confirmed it was about 50% discharged which meant it was as good as new despite its 13 year age (3 years beyond its "design" life & 8 years after it was scrapped for UPS reliability reasons).
Ok, that was a lot of ramble, but FWIW.
You don't have an Optima. IMO that's good. IMO they were once good batteries but they took a dive a decade or 2 ago. Some still swear by them, but I know of too many failures.
My battery supply Guru stopped stocking Optimas ages ago - and disappointingly Odyssey which I held in high non-practical regard - due to high return rates etc.
He recommends Deka which I read are well regarded stateside as well.
Also IMO Kinetik get god reviews stateside.
FYI - I found out my UXH38-12 retailed for AUD$670
but the UXH100 (or UXH110?) retailed for $500. So 2.5 times the capacity and 25% cheaper. And if the 38AH handled my starter, a 100AH would romp it in. (My starter was 240A until I changed to a 140A reduction starter.)
With ~70AH Optimas retailing for $450 (maybe $350 in practice) I had no doubt which battery I'd choose - ie, the Yuasa UXH100-12. I'd be surprised if that did not last at least 20 years.
However since then a Guru-recommended dual-terminal ~110AH wetcell for $220 so that'll be my eventual camper & remote choice. (Main battery, maybe a 2nd in the engine bay AND/else another under the vehicle.) Apparently they are great as crankers for 4WDs, and for winching, and as deep cycle solars. That is unusual in that batteries are either crankers (high current) else deep cycles (low & slow current) by physical design, or a compromise between the two. Maybe it's a deep cycle but being so big (as for big AGMs) high currents are not such a big deal.
Geez I ramble!
Posted By: efx26
Date Posted: September 30, 2014 at 2:05 AM