It's late here, too (02:30)
Originally Posted by OldSpark
Final (may be) decision: Monday morning I'll give a shot to a YUASA NP 12-12. If it last less than a year in the car then it will be replaced with YUASA TEV 12180. That's what our suppliers keep in stock.
NP 12-12 is about 42 USD here, while the TEV 12180 is 73 USD.
I choose NP 12-12 mostly because it's size - 10sm width / 15sm length and the critical size for me - HEIGHT is 10sm. This will let me install it in a secure place with closed top cover, while other batteries were to go above the provided box and wouldn't let close that cover. It's fine too, they would stay secured, but why it look ugly when it could look pretty :)
Thank you OldSpark. I'll keep you informed, and just in my style (if you've read my thread from beginning) everything will be well illustrated, why not filmed :)
Beware those Yuasa NPs. I had one and it only lasted 23 years.
LOL! It was an NP12-4 (4AH) in my family home's alarm which I installed in the 1980s and it's still going strong. We tested the battery yearly to check its 24-hour reserve and on the 23rd year it failed (I can't recall if it was hours or minutes).
Upon replacement I realised how old the beast was. Yes - Yuasa were definitely a QUALITY battery (something I learned from the 1970s when replacing motorbike batteries).
FYI - I replaced it with the 7AH NP12-7. It was the same price and merely required the cut out of one panel, and vertical mounting instead of horizontal.
Sure, that was standby use where a battery is normally not used and merely sits on float for most of its life - and in theory (ignoring chemical aging) it should last forever - but still, IMO 23 years is ridiculous. Even HUGE telco 2V wet cells with 20-year design lives which are maintained (with 3 monthly checks etc) don't last that long, and they are likewise "standby" batteries which traditionally were wet cells thereby enabling equalisation and other life enduring practices.
Anyhow, that was something I was going to mention. Sucking & seeing a battery like the NP might yield surprises. They are quite a battery, not only suited for standby with low current loads (as in an alarm with 24-hour reserve), but also cyclic crankers (they are used in motorbikes etc).
And 23 years - that really exceeds the spec. I think they are a 10 year battery tho maybe only 5. But IMO those specs usually mean ideal conditions on float and probably unused - you then subtract for the number of discharges, their discharge rate & depth, time to recharge, temperatures, etc.
BTW - my NP12-4 testing was very scientific - I'd disconnect the AC and the battery was deemed flat when the PIRs stopped detecting movement and did not light up. Now everyone knows you should not test a battery by "flattening" it - it should be done with a known load to a predetermined set point (ie, never less than 10.5V or 1.75V/cell for most batteries). But despite that abuse she still lasted 22+ years. (AFAIK the alarm does NOT have any LVCO - Low Voltage Cut Out or "battery protector", and I'm reasonably certain it did not have any sophisticated charging algorithm. Though it was a brilliant alarm - a locally made IEI unit. IEI also made the VESDA - Very Early Smoke Detection Alarm - which became popular in many critical environments internationally.
I guess now I will have to read the rest of this thread. (Rats!) I'll bookmark it for now (into my round tuit folder for which I'll need a 23" x 16 mile screen to read) and pray I don't find anything that rings alarms (is that a pun or post-segway?).
Alas I rarely read or re-read earlier pages of threads (that's something that can partially backfire as in AutoWiz's My Accord build carputer communicating with ecu REAL TIME TUNING) but I happened to spy your request due to fate (aka your PM).
But you have researched etc, and have probably gone nuts over the application of battery specs and balancing all the different factors involved. I go nuts too except where the application is fairly clear cut - eg, regular car crankers or long-slow solar systems etc. Even then, IMO nothing would top the experience of someone that has had that precise application, and hence why I heed the advice given by certain battery suppliers etc. [ I love my supplier. His customers come back - albeit usually after 8-10 years LOL - and he experiences his typical car & 4WD applications and hears of solar and other customer applications including golf carts & bikes etc. He confirmed early on what I knew (that Apollo batteries were crap) and later similar for Optima and even my "theoretically beloved" Odyssey (where I accepted his comments tho unexperienced myself). And where he contradicts me, I'll follow his wisdom - tho that has never happened on the theory side, but I'm still out on batteries flattening on concrete (I have yet to confirm if his were thermally equalised - long gone are the days of batteries flattening on concrete, at least according to all "documented experts" I know of. ]
One grace is that battery specs are usually conservative - they should cover 95% or 99% etc of their released batteries. And given the spread of manufacturing possibilities, that could mean exceedingly under-spec'd in some cases. But any non-spec abuse could kill the battery quickly (over discharge, high temperatures, excess charge voltage or current).
Again, my usual ramble. But that's the art of batteries.
PS - Ped: Battery ESR is not the same as battery internal resistance. That's somewhat pedantic but I suspect some think ESR is internal resistance and use them interchangeably - but the 2 should be similar anyhow. Technically ESR is what "we" want for short circuit (current) & voltage drop calcs - even though a battery's resistive voltage drop is (or should be!) insignificant at the currents we use - and I'd expect most do give the ESR which is easy to determine.
I ordered one YUASA NP 12-12. After 2 days it should be on my desk, so this weekend I'll mount it in the car. At first it won't be in use as the PC is not ready to be mounted in the car, yet. The battery will just be mounted with UIBI hooked, but no devices will be powered by it. This will give me time to monitor it's behave, without been discharged at all. What I'll be monitoring - voltage while charging, voltage when separated and temperature (by feel). Do I miss something?
I've seen a couple posts by you where you mention about the 20+ y.o. NP :) BUT yes, there you have the perfect conditions - proper voltage, proper temperature storage and no discharge. Again 20+ years... huh...
About reading the rest of my thread - you don't need to, except you're interested what I do. I made some things in a harder way, or just things that nobody has done yet. Well it's just enough to have a look only to pictures, and in case you like sth, then read the rest :) A couple of times I changed my conception, too. The idea of building a CarPC is more than 5 years old. At that time I was driving VOLVO 440. Then 460, then S40 and now S80 ... So the conception of the display mechanics has been changed a lot of times. Here I've showed only the last idea of using genuine up-down mechanics. For PC case I use a case of genuine car CD Changer. Buttons on dashboard also are genuine. When I'm done, it should look like factory fitted system.
Oh, the battery - it's going to go INTO the box of the genuine RTI electronics case, which just like the CD Changer has it's own mounting bracket in the trunk. This box I plan to be the new home for the aux battery. It is 300/105/105 mm. (w/l/h). And that's the main reason for choosing NP 12-12 rather than 12180. To be honest I'm still thinking of finding a suitable place for bigger battery in case the NP 12-12 fail too early. But NP 12-12 will fit in there perfectly leaving just enough place to mount the relay next to the battery. So I'm thinking to leave it with only one fuse, as the cable between the relay and the aux battery will be 5 sm (2 inch) and will look like this:
Main battery -> fuse -> Relay -> Aux battery
Am I fine this way? There still will be protection of huge amperage, but as it will be almost impossible to make short between relay and aux battery, I see no sense putting a fuse there.
I'm happy my thread is live again :) I like writing long posts, too. Just the fact that English is not my mother language makes it a bit difficult for me, and you saw it - I used "Float" instead of "Current". Well that's because of the translator. I know what they both mean, but translated it backwards. Sorry for that. Once I've done similar funny translation replacing "ironing" with "soldering" (I felt so shame then, just like now). Please excuse me for such mistakes. I reread all my posts 2-3 times before posting them, but even then there are still some grammatical and spelling mistakes.
Thanks for understanding and mostly thanks for the help. I really needed to hear from somebody with enough experience with batteries that I'm good with np12-12 and all those long nights searching and reading was not for nothing.
Ha ha... Re your Main battery -> fuse -> Relay -> Aux battery single fuse I was going to say "mount the relay as close to the Aux battery as possible", but you then write "as it will be almost impossible to make short between relay and aux battery..." (... and "... I see no sense putting a fuse there").
In other words you are relying on physical security rather than electrical security for protection which is exactly what my "relay close to the Aux" meant. IE - the relay to Aux battery fuse (as near the Aux battery as possible) is in case the cable from the Aux to the relay shorts to GND, and also if the relay or its cable to the main battery's fuse shorts.
Relying on physical security means to "ensure" that no short can happen to the Aux to relay cable. You should also ensure physical security of the relay itself and its cable to the main battery fuse, but essentially the relay itself becomes the fuse should that cable ever short. You could add the fuse on the main battery side of the relay as that will blow rather than the relay if the cable shorts... That may seem strange to some, but should make obvious sense in this case.
And if the relay is also isolated/insulated from the chassis/body/GND then it cannot short to GND. The only risk then is the relay flaming if is fuses as a result of a short, but that is rare - a short usually melts the contacts quickly and hence breaks the circuit (except when the molten parts then short the input +12V to a heavy relay GND - ie, chassis etc.
Bear in mind that the relay should not overheat and (slowly) melt due to an overload - the main battery fuse should then blow and break the circuit. We are only considering short-circuit type faults.
There are times when fuses are bad. For example, MAYBE if you had to run a long cable from the Aux battery to be able to mount the fuse somewhere else.
I have occasionally used the following pic as an example:
... as shown in the 9th reply on the12volt's big 3 upgrade on integra, fuse box?.
That horizontal 200A fuse (left side about 1/3rd up the picture above the rectangular black box) is fitted between the alternator and battery +12V. (Note that older vehicles never had such a fuse. Instead they relied on "physical security" in the same way that battery +12V to starter motor cables still do.)
IMO that installation would probably be safer without the fuse - IMO the long cabling and its routing is ridiculous. If kept, I would certainly be fitting a robust insulated sleeve (cable protector or tubing) over that whole cable length.
If the above ramble is vague, it's supposed to confirm what you already know or have done (as being an acceptable method provided the risks are understood).
And don't worry about your English - it is fine. (Dare I say pretty darn good or even excellent?)
I knew what you meant by "float", but just in case you meant it some other way...
As to the NP - I know it was a VERY popular & common battery series. I gave one example of its amazing longetivity in standby use. Hopefully Century-Yuasa have not changed its manufacture (for the worse) since Yuasa manufactured them.
Without asking my guru for his recommendations - nor without researching what new[ batteries may be better - it's quite likely to be the battery I would have recommended - subject to your local prices and supply etc.
FYI - the NP series had an NPH variant - a High current discharge version. But I suspect they'd be rarer and more expensive. Let's see how your NP holds up.
Here is my plan:
The only thing not shown here is the big fuse between the two batteries. I'm still searching for autoresetting 80A. In case i don't fine one untill this weekend I'll place a regular fuse, but the searching will continue.
The green wire named "+12V REGULATED" is a +12 taken from PC's SATA power plug. It will power the monitor itself and a Relay, which will control the powering for the switched-by-PC-state consummates (mostly USB devices with external power).
What do you think?
The 12V regulated isn't needed for the relay, but as a way of shutting down all PC peripherals it makes good sense - provided none are needed for post- (or pre-) shutdown stuff (but the coil could be diode isolated & connected to another +12V source for extended ON).
I presume the hubs & phone charger are 12V else have a 5V supply. (If 12V, maybe it's automotive 12V hence can be unregulated.)
An 80 self-resetting CB may be difficult or expensive to get. As per previous, the largest I have seen readily available are 30A in ATS fuse format, and 50A for "micro relay sized" stud types.
A 50A CB is good for 40A continuous using the usual 70-80% of rating rule, but can of course handle 50A continuous (and probably 55A), and 100A for probably 20 seconds or longer.
Get an 80A CB if you think that's what you need, but if only running up to 40A I'd try the 50A. The battery inrush & reducing charge current should be handled by the extra 15A overhead (55A total) and if higher than 55A may still be ok provided the charging during the ON time is greater than the battery drain when off (CB = open circuit).
But otherwise thinks look ok - provided the alternator D+/L can handle the relay coil's +12V current, and noting the alt's B/B+ main power to battery(s) is not shown, nor the batt(s) 0V/GND to chassis/body connection.
Yes, I use the "12V regulated" to control the upper 5 fuses. I know it's not needed for a relay to be controlled by regulated voltage, but the logic here is what forced me to do that.
Fuse: Car's wiring is this way:
Main battery -> 10sm cable -> a box of stud type fuses (with two free places) -> cables to devices
So the cleanest and stock look install I could make is use one of those free stud type fuse holders and hook a 80A fuse there.
From there to the 120A with a 60-80 sm cable and then to the 2-nd battery.
I'll tell the truth for the alternator - I haven't yet tested it whether it will be able to engage the big relay or not. If not I'll play abit with some optocouples :) or maybe there is other known way to handle that?
About the GND - I plan to run a GND wire for EVERY device all the way to the battery. Hopefully this way I wont have the usual GND problems. Only the time will say ...
I'm preparing for tomorrow.
The fusebox which is gonna be used:
It's a genuine Volvo box, taken out from S80.
This is the MainFuse holder. It's the first security just after the main battery. There is 10 sm cable (the bigger one) which is connected to the main battery. Here I plan to place a 80A fuse and run a wire to the UIBI's relay, then to the 2-nd battery.
Here is the new home of the 2-nd battery:
It's NOT sealed and the battery fit perfectly in there, but still there is place for eventual distend of the battery.
Relay is secured to the box with bolt, so nothing can move in there. In there will be and a 5A fuse for the cable coming from the alternator. I'll find a way to secure it, too.
Right now I'm assembling a 14 pin connector, again taken from VOLVO S80. There were only 5 pins used, but I need all 14 possible
I'm done with the right one. It was populated just like the left one. What a waste - nice strong big connector but only 1/3 of the pins in use. Not any more :)