How to burn out your alternator while direct charging LiFePo4

[TWIH]

I have a serp belt & good fan on the Ambo so I'm good but didn't let it idle to charge & now check the master. I draw 13 amps to run at 70mph.

This is a comment from the article posted Lucian Popescu  tkteun • a month ago
Normally yes but we were talking about idle. There are special vehicles used stationary, having high power demand (ambulances, police cars etc)

I’d think that one of the advantages of an econoline van is that you could get a large case police/ambulance alternator to replace the small case (assuming clearances fit), since Ford did engineer those for hd usage.

Question 1, if you are concerned about idling, would it be better (or reasonable) to just use the simple on/off 1/2/combined switch instead of a cd solenoid? That way you’d have more control over when the alternator was trying to charge the depleted house bank. You could then avoid the idling issue altogether.
Question 2, If you are driving on the highway and then switch the dial to the house bank, will that sudden surge/demand do bad things to your belt?

Lastly, anyone want to buy me this after BF Amazon deal? 

Fluke 117/323 KIT Multimeter and Clamp Meter Combo Kit
by Fluke
[i]4.6 out of 5 stars[/i]    183 ratings
List Price
$354.99 
With Deal:
$216.99 
You Save:
$138.00 (39%)

[sternwake]

The continuous duty solenoid can have a rocker/toggle ( illuminated) switch placed inline  on the 12v ignition trigger circuit.   I always recommend this, for situations such as Gary's when the hungry battery and high output alternator can overwhelm the cold damp single v belt. If one flips this switch to on at 60mph with warm and dry belt and pulleys, will the sudden strain of a depleted battery asking for 50+ amps hurt anything?  I doubt it,  but the belt might slip or chirp or squeal.  A glazed belt from too much slipping when cold and damp should be replaced and the pulleys likely wirewheeled clean of the residue.  The condition will just get worse until this is done.

A 1/2/both/Off switch located where the driver can easily reach it, is hardly ergonomic, and turning it to off while engine is running can smoke the alternator.

Those hell bent on idling parked to recharge for more than 10 minutes are perhaps best off with a forced cold air feed tube aimed at alternator, but a large case alternator, if it fits, is certainly an upgrade. Whether large case alternators have better cooling or make less heat or both is not something I can say for sure or not, as doing so would be repeating others opinions, and I've grown despise the internet parrots.

There's way  more than one strategy to skin this particular cat.

I think readers should just be aware that idling parked to recharge a lot of depleted  battery capacity might be able to smoke their alternator, or reduce its lifespan greatly.  There's all sorts of ways to avoid overheating the alternator, and for some the ignorance is bliss and it 'works just fine' is just fine, for them, for now. Some others will have alternators which once they get too hot automatically lower the voltage and they would only overheat at that point if the loads other than the depleted battery were still a large percentage of the capacity of the alternator,  and this is likely only accomplished with additional forward lighting or a winch or a boom boom  get the fuck away from me with that crap music, stereo.

If ignorance is infuriating, then collect data with the tools and initiative to do so, and by all means share that data.

In 2004 I bought a reman lifetime warranty alternator at Kragen.  I used that warranty at least 3 times pre 2007, when I got solar, and twice since, the last being July of 2015 when Oreilly's handed me a new Wilson reman when I handed over the failing one.  Since then I have added the external adjustable voltage regulator and can work my alternator even harder if I choose to as the stock regulator in engine computer rarely asked for 14.7v+ for long.
 I can replace my alternator in 15 minutes, but on some vehicles the task is a nightmare, and the price of replacement much higher. 
Everything one can do to insure best possible alternator recharging of depleted additional batteries with engine running, puts more load on the alternator.  Its kind of foolish to try and extend the life of a 100$ battery by sacrificing a 600$ alternator.

One valid  strategy, among many, for protecting it from overheating can be to use no thicker than 8 awg cable to feed depleted house battery(s), and sacrifice some of that 'best possible recharging'

As Usual, Mainesail has a good info packed article worthy of a read by those interested in such topics.  His opinions,  on these topics, are the closest things to facts one will find on the internet.

https://marinehowto.com/automotive-alternators-vs-deep-cycle-batteries/

https://marinehowto.com/programming-a-ba...regulator/

https://marinehowto.com/marine-alternator-installation-tips-tricks/

[TWIH]

SW, thanks for the continued reminders on this topic, I just have 1 last question. While I understand that the 1-2-both-off switch is big, what I don’t quite get is how turning it off would be any different than the solenoid on/off toggle.

I suppose the other option is a cheapo WM marine battery connected thru the 1-2-both switch so that juice from the alternator did have somewhere to go, yet would even the momentary “off” as you switch between them be a problem? Dissimilar battery chemistries he we go.

Edit, read the first link, basically boating is an expensive hobby! It was a good discussion of alternators and temperatures. Still keeps the water muddy for vehicles though, I know you have both the variable voltage setpoint and the additional cooling but for many, that won’t ever happen.

I’m still wondering what all these lithium drop-in peeps are thinking when they install such a power hungry battery, even if they have 0 or 2 gauge wiring to feed it.

[sternwake]

A 1 2 both off switch is fine when switxhing fromn1 ton2 r fromneitherntonbothnand back., buf off is likendisconnectingnthe battery from the vehicle.all together. It can cause electronics frying voltage surges and blownd diodes in the alternator.
Most switches are make before break buth those that break contact when spinning exist and are no good.for.switching under load

[Trebor English]

SW, thanks for the continued reminders on this topic, I just have 1 last question. While I understand that the 1-2-both-off switch is big, what I don’t quite get is how turning it off would be any different than the solenoid on/off toggle.

I suppose the other option is a cheapo WM marine battery connected thru the 1-2-both switch so that juice from the alternator did have somewhere to go, yet would even the momentary “off” as you switch between them be a problem?  Dissimilar battery chemistries he we go.

Edit, read the first link, basically boating is an expensive hobby! It was a good discussion of alternators and temperatures. Still keeps the water muddy for vehicles though, I know you have both the variable voltage setpoint and the additional cooling but for many, that won’t ever happen.

I’m still wondering what all these lithium drop-in peeps are thinking when they install such a power hungry battery, even if they have 0 or 2 gauge wiring to feed it.

The "1-2-both-off" switch can connect either, both or no battery to the alternator.  A switch to turn on and off the connection from the alternator to the house battery never turns off the starter battery leaving the alternator with no battery.  If the alternator is producing some amps it is because it has both RPM and field current.  Take away the battery and the same amps and field current will make a higher voltage.  Before the engine control computer can turn off the field current the voltage could get high enough to roast stuff. 

Even a momentary, brief to human time scale, could be a long enough time to roast electronics. 

A "1-2-both-off" is usually set up so that the order is 1-both-2-off-1-both-2-off rotating one direction and 2-off-1-both-2-off-1-both rotating the other direction.  That way switching from 1 to 2 can be both between 1 and 2.  Rotating the opposite direction you get off between 2 and 1. 

With the engine running the intermediate "both" position assures always at least one battery.  Without the engine running the intermediate "off" position assures that dissimilar batteries aren't connected to each other.  

Meanwhile, the LiFePo4 BMS shuts off the battery when it is full.  If it is the only battery at that time and it goes off then you have a no battery condition.  That could cause a roasting.

[Trebor English]

Once I studied the installation instructions for a voltage sensitive relay.  Basically it is a circuit that senses the voltage and turns on the relay when the voltage is high enough.  Only some kind of a charge source would make the voltage high enough. 

It was a lower priced unit.  The instructions came with a chart for wire size and wire length.  The intent was to have enough resistance to keep the peak current low enough to protect the relay switch contacts.  Shorter wire length required smaller wire.  The chart listed the minimum length for each size wire.  I don't remember the details.

If you have a minimum of 6.25 feet of AWG #12, 10 feet of AWG #10 (0.01 ohm) and a minimum of 16 feet of AWG #8, and 25 feet of AWG #6 you will have a large widely dispersed resistor to limit the current and dissipate the heat over a large area.  If you still have too much current double the wire length or reduce the wire size.  Don't forget, AWG #10 should be limited to 30 amps, AWG #12, 20 amps. 

I'm sure that having the minimum wire resistance in the instructions saved the manufacturer a lot of money on replacement of failed units.  Some units were protected.  The ones that weren't protected weren't replaced as it was the customer's fault installing it incorrectly. 

This same plan would work for the biggest lithium or AGM battery and the most tiny alternator.

[Roadtripp]

Ive seen on-off battery switches with small terminals labeled “field” next to the big terminals. Perhaps this switch can be used safely between a alternator and battery? And perhaps this would be a good place to place a potentiometer? For a external regulator and a resistor fooled computer.

[sternwake]

The battery switches withadditional smaller terminals... field terminals shut off the field current from regulator.to.alternator.to.prevent turning it off under load and blowing the diodes.
Only externally regulated alternators.need apply

[sternwake]

The Transpo540HD is the external regulator I am using. It had a potnetiometer inside of it. I dug away at the potting to reach the pot's legs and nipped off the pot itself, then soldered wires to 2 of its 3 legs, then ran those wires to through a computer fan connector to my dashboard next to my digital voltmeters.

Spin a dial and watch voltage( and amperage) respond.....its a bit addicting.

The original wires attaching to my externally regulated alternator now have a 10 ohm 50 watt resistor attached to them instead of the field terminals of the alternator. no check engine light.

BUT, If the engine computer sees voltage over 1 volt higher or lower than it is expecting to see, for a duration of 30 seconds, then the check engine light does come on, and MPG and power suffers until I reset the computer. Basically it never comes on unless I allow over 14.7v which does happen on occassion as some of my VR and alternator wiring is not ideal, and there is a little rubber band effect once the wires warm up and have more resistance. Usually when everything is hot and I had dialed in 14.7v cold at higher rpms, when hot and idling that will drop to 14.2v. I then crank it back upto 14.7v, but then step on the gas and it can go above 15 and the CEL comes on.

I paid a ridiculous sum for that 50 watt 10 ohm resistor, and alternatorparts.com had grinded off the resistor value. They can be had for 3$ or less on Ebay. I did not know the value required though so I guess I paid for that info more than the part. I attached that resistor to a bigger heat sink, and in retrospect I would have gotten a 100watt 10 ohm resistor instead. It does get quite hot so my computer voltage regulator is wasting amperage sending field current to the resistor. I can easily return the computer back into the loop if the transpo540 were to fail.
In that regard, I have added a heatsink to the transpo 540HD regulator, and a K type thermocouple, and was surprised to see it was getting to 160f, with a low battery and low rpms, just when it sends maximum field current to the armature. I added a 60mm fan because of course I did, and now when it is fully fielding the Alternator it only gets to 128.8f. Should be much more reliable long term with both the heatsink and fan.

I'd really like to get another alternator to have as a backup and rebuild it with well overspec'd Diodes and pepper the rectifier plate with heatsinks and move the temp sensor to that. When I last needed to use my lifetime warranty it took Oreilly's a few days to get the right alternator, since they were only used for 2 model years in some chrylser vehicles, but previous to that they always had one in the back.

I've not really explored what other externally alternators will fit. and that easy peazy lifetime warranty and the ease of replacing the alternator, has kept me from trying. Also with dashboard voltmeters and ammeter I can so easily see if the alternator were to fail or lose output that i am unlikely to get stranded. with a good fully charged battery and 12.2 amps of load at 2K rpm i could also drive quite a distance even with a failed alternator, at least in daytime.

When my last alternator failed it was still working, but could not muster much more than 20 amps, and some guy I know who claims to have rebuild many alternators said it sounded like a shorted stator, and that is the part which appeared to have released its magic smoke in that video several posts back.

Rebuilt alternators have a horrible reputation, and I have had great ones, and ones which I installed and then removed and returned without having left the parking lot.

If Oreilly's were to cancel my lifetime warranty, I'd be all over improving upgrading the alternator itself.

BUt truth be told, I would only really benefit from more amperage at idle as at night with lights and blower motor on high and a depleted battery there is very little to nothing left for battery charging. But idling at night at red lights with a well depleted amp sucking battery is hardly an every day occurrence. If I were to have a lot more battery capacity then I would benefit more from a higher output better designed and built alternator, but i have learned how to survive on one single 90Ah AGM battery for both house and engine starting duties, and that single battery is limited in its duration to max out the alternator.

Now if I were a wage $lave, going to work before sunup everyday, that would be a whole different story. Everyday that alternator would be maxed out and working super hard for a good period of time. Any Idling or driving under 25mph, would have its temperature skyrocket. But as I've already said I can just dial back my voltage regulator to take load off the alternator at idle or sub 25mph speeds, to greatly slow battery recharging and prevent alternator overheating.

I know people in this day and age expect everything to be automatic and do things perfectly while humming their 'works just fine' mantra, but regarding battery charging almost everything automatic sucks festering donkey balls, and can not do nearly as good a job as a human with a brain, a few gauge, and a voltage dial.

[Blacktank]

i have a toggle on the solenoid activation wire,a lighted switch would be better but either way you got to remember to turn it on/off