LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[transmitterdan]

Almost all "automotive" alternators with internal regulators have thermal fold back built into the regulator module. The temp sensor costs only a couple pennies and it saves the manufacturer tons of grief during the warranty period. It's the external regulated ones that you have to watch out for as many installers don't know (or care) to put on the thermal sensor.

[NahanniV]

Originally Posted by hellosailor

"Could you point out a particular internal regulator that has no thermal protection ?"
Can you find a single alternator (remember, I've been clear to say this is about automotive alternators with internal regulators) where the shop manual shows, or even mentions, that there IS such a component? In how many of their hundreds of models?


Those companies you mention may MAKE such parts, but now let's get back to the real world. Does Delphi (which spun off the Delcos), or Leece-Neville, or Hitachi, or Denso, built in such a component?
....

Delphi:
"Notes: With Temperature compensation"
D702HD - Voltage Regulator For Delco CS121D, CS130D Series Alternators Used On Buick, Cadillac, Chevrolet, GMC, Isuzu, Oldsmobile, Pontiac, Saturn

Bosch:
"A high-temperature shutdown reduces the flow of current"
http://aa-boschap-au.resource.bosch....12-10_en~1.pdf

[hellosailor]

I see the Bosch alternators mention "thermal protection" as being among their innovative [translation: not normal for the market!] features. But the Quickstart page, which is selling replacements not genuine Delphi/Delco parts, only says that regulator is temperature compensated, which means something totally different. It means the output voltage will be varied to provide optimum charging voltage based on the ambient temperature. That's far short of full thermal self-protection, a very different thing from the Bosch claim.


Dan-
FWIW the Bosch claim is the first time I have heard such a thing. In all the circuit diagrams of regulators that I've seen (from Delco's service manuals and from some of the "twelve volt" books that show many types in lesser detail) I've never seen a component designated as a thermal protection device.
Remember that when a temps sensor only costs two cents, and you're making a million cars a year (which is barely a dent in the US market), that two million cents you can save by not putting one in. Twenty grand. Estimates are some 16.4 million new cars were sold in the US last year, so...that's $328,000 saved by not putting a two-cent part in each one of them. Of course, with standard markups, that two cent part becomes four cents to the dealers, and eight cents to the customers, so possibly $1.5 million in costs on the consumer market--for just one year, for just one two-cent part.
Twenty grand at a time, the "forensic engineers" push up the profit line for all kinds of companies today. Bosch? Supplies mainly the big three German makers, I would think. And those three have their own peculiar logic for everything.
Does Bosch supply many boat builders? Any on the US or "Western" or "Far Eastern" markets?

[transmitterdan]

If you dig into it you will find that the integrated circuit that is encapsulated in the internal regulator does the temp fold back. I am not aware of any of these modules that do not have temp fold back. If they did not there would be thousands of dead alternators every year so the cost of the temp fold back is trivial compared to that. As far as I know the standard alternators for boats are ignition proofed but otherwise use the same regulator module as automotive alternators. The boat market isn't big enough to warrant a boat version. That's why there is a small market for expensive regulators like Balmar make.

[transmitterdan]

"Modern" autos have the alternator regulator controlled by the overall engine control unit (ECU). It takes into account the engine load, ambient temperature, electrical load and other factors such as acceleration. All of this buys a few tenths of a kilometer per liter and reduces emissions slightly. They spend a lot more than 2 cents on all of this elaborate engineering.

[campr]

I was thinking of using an air-con type electro-magnetic clutch to start-stop charging.


http://amzn.com/B000C2Q4DS

That way I can just the 12V charger output from my BMS to activate the drive of the alternator. No fields to cut.

Just worried that the diameter of the driven wheel might be too big, not allowing the alternator to spin quickly enough.

I'm intending to give this a go, and will let you know the results.

[hellosailor]

OK, Dan. I'll take our word on it.
I know that "modern" electrical systems play many sophisticated computer games, some quite baffling and others actually leading to earlier failures. (Like, Delco built a series with spike protection in them, and since tat always eventually wears out, the industry panned them because it meant the entire alternator failed faster than it would have without them! Which wasn't a happily accepted explanation to the customers, who didn't believe in faeries, or spikes, in general.(G)


I know Bosch does some odd things, try attaching a voltmeter to a car that has a Bosch alternator and watch it swing from 12.4 to 14.6 with no apparent rhyme or reason. Perhaps drawing conclusions from battery state and power drains, perhaps just "We'll you show who won that war!". All this stuff was engineered for a purpose and it is marvelous when it works--but like the "new" digitally controlled kitchen appliances, it can be a bear when it also inevitably goes nutso on you, and there are no uniform diagnostics to be found.

[Maine Sail]

Originally Posted by hellosailor

OK, Dan. I'll take our word on it.
I know that "modern" electrical systems play many sophisticated computer games, some quite baffling and others actually leading to earlier failures. (Like, Delco built a series with spike protection in them, and since tat always eventually wears out, the industry panned them because it meant the entire alternator failed faster than it would have without them! Which wasn't a happily accepted explanation to the customers, who didn't believe in faeries, or spikes, in general.(G)


I know Bosch does some odd things, try attaching a voltmeter to a car that has a Bosch alternator and watch it swing from 12.4 to 14.6 with no apparent rhyme or reason. Perhaps drawing conclusions from battery state and power drains, perhaps just "We'll you show who won that war!". All this stuff was engineered for a purpose and it is marvelous when it works--but like the "new" digitally controlled kitchen appliances, it can be a bear when it also inevitably goes nutso on you, and there are no uniform diagnostics to be found.

Temperature protection by reducing the voltage limit is not uncommon and one of the main reasons Yanmar / Hitachi alts murder so many lead acid batteries. Most of the newer European alts have this. Some domestic alts such as the Leece-Neville 8MR series (Motorola style) do not do this.

This is where an external regulator shines. Instead of reducing the "limiting voltage" to try and reduce current output, the external regulator reduces the field, which reduces current output, but still allows the alternator to keep the same voltage setting. When the alt is hot it takes longer to charge but you actually get to the proper absorption voltage as opposed to almost always never getting there with a temp gradient alt..

That said, despite this protection, I still see about 3-4 burned up Hitachi alternators per year. This usually occurs on a very large flooded or AGM banks that have been deeply discharged and the voltage reduction/gradient, due to temp, is not enough to keep the alt out of an overheating bulk current output..

[Highland Fling]

WE have an Ex Moorings Boat they ditch the marine alternator modify the mount and fit a car style Delco Remy (now one wonders why they do that......surely shirley it is to reduce call outs and chase calls to charterers as it is a more reliable alternator.) In our case we have a 60A 10SI mode,lt is internally regulated BUT with external battery sensing a THREE WIRE MODEL......these are rather nice alternators that make expensive marine alternators look silly...A 12SI model with 140A for $100.00 and 200A for $140.00 and these babies are avaiable world wide at any auto store.

I have not modified it in any way BUT you can get the regulator in various voltages the standard one seems to work fine for my application.

[hellosailor]

The 10SI and 12SI are classics. I forget which offhand, but one or both of them will out out gobs of power at idle speed, and put out maxi power continuously at ridiculously high rpms as well. Not to mention, they're all over the place. The parts guys just usually only know "What car is that from?" so a little digging is sometimes needed.


I keep promising myself to run down to the patent office...I've got a suspicion that with a simple machine shop, any idiot could put some fine fluting on the outside of an alternator housing, any alternator housing, and easily double to amount of cooling that took place.


What say, Maine? You got a fluting machine & enough curiosity to use it? (Or any citations that say there's a reason not to do this?)

[Highland Fling]

Originally Posted by hellosailor

The 10SI and 12SI are classics. I forget which offhand, but one or both of them will out out gobs of power at idle speed, and put out maxi power continuously at ridiculously high rpms as well. Not to mention, they're all over the place. The parts guys just usually only know "What car is that from?" so a little digging is sometimes needed.


I keep promising myself to run down to the patent office...I've got a suspicion that with a simple machine shop, any idiot could put some fine fluting on the outside of an alternator housing, any alternator housing, and easily double to amount of cooling that took place.


What say, Maine? You got a fluting machine & enough curiosity to use it? (Or any citations that say there's a reason not to do this?)

The what car are they for? relates 'mostly to' ONE wire or THREE wire regulation AND the Clock position of the terminals.....the clock position is easily changed IF it is a problem for your application.......Get a 12SI and Air Cool it with a 4" fan on the back or with a felxy hose if you don't have the room...for a fan on the back Forget the fins you could always just paint it WHITE and double the price

[hellosailor]

Paint? No no no! As an engineer at Delco explained to me a long time ago, the heat dissipation on those things is very carefully planned. A lot of alternator shops do rebuilds and then spray the whole thing shiny silver--and the silver spray paint that makes it through the slots and coats the diodes, is just enough extra insulation to guarantee a failure within 90 days. Ooopsie.


So, painting the naked aluminum housing? Nah, I'm not going to push that luck. I don't care who does it for "protection", I suspect they are looking at a larger picture and dealing with that other ways.


When the guys in any of the auto chains ask you what alternator you want, their stock WILL NOT say "10si" or "12si". They need to hear "85 Cadillac, 429 engine" or "S10 pickup truck, gasoline engine" and that's what they pull. If you pick a slow day and ask nicely, they'll open up the likely boxes and look for the actual embossed plate on the alternator frame--and THAT's the only place you can confirm what it used to be. Before someone rebuilt it.


If you can find a counterman that's old enough to vote and drink...you may have better luck.(G)

[44'cruisingcat]

So... to save me reading through 4800 posts... has anyone had LiFEPO4 batteries for a long time yet? Like 10 years or more?


Just wondering if the cycle life span has turned out to be as good as claimed.

[Highland Fling]

Originally Posted by hellosailor

Paint? No no no! As an engineer at Delco explained to me a long time ago, the heat dissipation on those things is very carefully planned. A lot of alternator shops do rebuilds and then spray the whole thing shiny silver--and the silver spray paint that makes it through the slots and coats the diodes, is just enough extra insulation to guarantee a failure within 90 days. Ooopsie.


So, painting the naked aluminum housing? Nah, I'm not going to push that luck. I don't care who does it for "protection", I suspect they are looking at a larger picture and dealing with that other ways.


When the guys in any of the auto chains ask you what alternator you want, their stock WILL NOT say "10si" or "12si". They need to hear "85 Cadillac, 429 engine" or "S10 pickup truck, gasoline engine" and that's what they pull. If you pick a slow day and ask nicely, they'll open up the likely boxes and look for the actual embossed plate on the alternator frame--and THAT's the only place you can confirm what it used to be. Before someone rebuilt it.


If you can find a counterman that's old enough to vote and drink...you may have better luck.(G)

SADLY you mist the point totally

[nixsee]

Hi all,

I have spent the past month reading this entire thread and it has been enormously helpful.

I have 8 CALB CA100s which I will connect in 2p4s. I won't be using this in a marine environment like most of you, but in my van/rv (like many of the more frequent posters - T1 Terry and Diugo for example).

I may look into solar later, but for now I will be exclusively using the stock (dumb) alternator in my vehicle to charge the bank. I plan to connect the LiFePO4 bank to the AGM start battery through a contactor which will be powered by the ignition. I will also have a manual switch in this circuit so that I can manually shut off the charging when it gets to my target voltage (13.8V pack/3.45V per cell), allow to discharge for a while and restart when I deem appropriate based on my driving plans. I gather that this will work just fine. I'll be monitoring the charging with both a Junsi Celllog and HousePower BMS's EV Display (using bluetooth and Android Torque app - I now realize this is probably overkill, but I bought it a while ago before reading this thread).

I just have some remaining questions that I couldn't find answers to in the thread. I realize some of them might be addressed in other threads in this forum and elsewhere, but I feel like it is still relevant given that it is a LiFePO4 system and many other newbies likely come here as a first read.

• AGM and Alternator:
  • Is it bad to have the LiFePO4 charge through the AGM start battery? The alternator will be running, but is there any risk of an empty LiFePO4 bank drawing the entire ~100A that the alternator can output and then also draw down the AGM? I'm sure it'll be fine, but thought I'd ask
  • How to monitor a dumb alternator's temperature. This has conveniently just been discussed, but I have no idea if my van's computer controlled regulator monitors temperature. Some sort of thermocouple with a display that I can watch?
  • As far as connecting the alternator, AGM and LiFePO4 together, should one cable go from Alternator to AGM, and then another cable from the positive post to the contactor and onwards to the LiFePO4? Or would it be acceptable to have two cables joined (perhaps through a busbar) to the alternator output and one goes to the AGM and the other to the contactor/LiFePO4? The second option would result in a cable run that is about 4' shorter, so less voltage drop. I also likely wouldn't have to upgrade the gauge of the existing cables to the AGM.
• Contactor:
  • How do I size a contactor? The Kilovac EV200 seems to be the default choice, or the Gigavac GV200 (which seems to be a cheaper and superior device), but they are rated at 500A. I may upgrade to a 145A alternator someday, but that is still well below the rating. Could I save money by getting something like a 150-200A continuous contactor? If so, any recommendations?
  • Do I need a contactor with Aux cables? I can't seem to figure out what they do.
• Fuses:
  • Do fuses provide the same AIC regardless of voltage? For example, Blue Sea Class T fuses seem to be rated at up to 160V DC - is the 20000AIC applicable at 12V DC, or just 160V?
    
  • I will have a fuse at the LiFePO4 bank, but do I also need one at the AGM battery or alternator? The van already has a 125A fuse built into the power center to protect its systems.
    
  • Do fuses go on positive or negative post, or does it matter?
• Adding LiFePO4 cells
  • If I want more capacity later, can I add new CALB CA100s to the pack? I realize they won’t match perfectly so some capacity will be sacrificed, but I don't see an issue with this. It would be the same as replacing a dead cell, no?
• Charging temperature
  • I use this van in the winter in Canada, so if I haven't been in it running the heat for a while, the bank will certainly be at below 0 degrees. I was thinking of running some sort of trace cables around the cells inside the plywood box I made for them. Any thoughts? Otherwise, I'll just heat the van before connecting the LiFePO4 to the alternator.
    
• LVC level
  • I have a HousePower BMS like many here. The LVC alarm (which I'll use to sound an alarm and light an LED) turns on at 2.9V and off at 3.1V. Is 2.9V a safe level to reach?
  • The protection level is at 2.6V - is this too low? Should I instead be opening the loads bus at the 2.9V warning level?

Please let me know if I've overstepped my bounds with all of these somewhat unrelated questions (there's been plenty of significantly more off-topic discussion over the years though). I'm happy to draw some diagrams to help explain anything.

Thanks so much for this amazing resource, I'm so glad I came across this technology before buying a bunch of useless AGMs! I plan to spread the good word once I have it all sorted out.

Nick