Can a lithium pack be charged by alternator alone?

D

DHK

New member
john61ct said:
No aircon setup can run long off grid from battery stored power.

All you're doing is time shifting the high-amps input, now doubled if you need aircon **and** recharging to be concurrent.

Figure 100AH storage needed per hour, and that's in mild heat, or excellent insulation.
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How about sometning like this one:
http://www.indelb.com/products/automotive/sleeping_well/sw_oblo
http://www.leangreenfleet.com/documents/Sleeping Well basic brochure.pdf
or portable one:
http://www.indelb.com/products/automotive/sleeping_well/sw_cube_the_first_in_the_world

12V 15 A/h @ Min - 2240 BTU

Is 2.2K BTU enough for a well insulated van?
 
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M

Midwestdrifter

Engineer In Residence
DHK said:
Is 2.2K BTU enough for a well insulated van?
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No. Maybe if your van was a freezer truck with 6" of insulation, and no exposed body metal. 2200btu/hr is about 650 watts of cooling power. I have seen home fridges with more cooling power than that!
 
R

rollerbearing

Well-known member
Midwestdrifter said:
No. Maybe if your van was a freezer truck with 6" of insulation, and no exposed body metal. 2200btu/hr is about 650 watts of cooling power. I have seen home fridges with more cooling power than that!
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Oh man - that just popped into my head an image of someone sleeping in a fridge with a neck hole cut out like an old iron lung. :thinking::thinking:
 
M

Midwestdrifter

Engineer In Residence
I have been toying with the idea of getting a small 1000-2000btu cooler unit setup to cool just a bed. Either via holes in the mattress, a cooling blanket, or some kind of liquid cooling pad (hospital style). Keeping a single person cool only takes about 200-300W of cooling power with a bit of insulation.
 
I

InterBlog

Member
DHK said:
Found a real user:
https://sprinter-source.com/forum/showpost.php?p=394721&postcount=17

looks like it is enough for cooling a sleeping cell :)[/QUOTE

Pasted from Expedition Portal below, for the 12 V version. 36 amps is still a considerable draw, but yes, it is potentially an option for some, presuming you can get your battery back up without killing your alternator.

***

- Basically a 15" cube that weighs about 43 lbs
- It has 2 hoses, and a water evaporator built in. So no water to drain, and dual hose venting/intake system
- 3,250 BTU. Enough to cool roughly a 130 square foot room in a house, or a typical small camper.
- It uses the highly efficient Secop BD350GH compressor. Secop is the same as Danfoss (same company). These are the same ones used in refrigerators
- The 12v version consumes 36 amps (with outside temperature @ 89 degrees, inside temp 77 degrees)
- Price is hard to find, but somewhere around $1500 US plus any shipping/import fees. Probably closer to $2k.
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J

john61ct

Active member
Midwestdrifter said:
No. Maybe if your van was a freezer truck with 6" of insulation, and no exposed body metal. 2200btu/hr is about 650 watts of cooling power. I have seen home fridges with more cooling power than that!
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And in ambient temps only a few degrees hotter than your target.

8000 BTU is a minimum IMO, double that for Texas-hot weather, even with tight & thick insulation.

Getting up to 200AH per "time shifting" hour there, and every AH you take out need to put 1.1+ back in, sooner rather than later.

Just run your little inverter genny, probably quieter than the aircon anyway.
 
J

john61ct

Active member
Note I'm not saying it **can't** be done.

Just that it's not practical enough to invest in the required megabucks, does not buy much real benefit.
 
W

wankel7

Active member
InterBlog said:
**OP beware.**

**Eslmooney beware.**

Even WITH the Sterling B2B, the extra wear on the alternator will make this configuration a very risky proposition.

How do I know? Because I have that exact Sterling and that exact Electrodacus in a T1N, and my Bosch 200 A alternator lasted a total of 16 months of very occasional use before its clutch pulley wore out. My alternator's effective lifespan ended up being measurable in mere HOURS.

What the alternator was DESIGNED to do and what we are ASKING it to do are two different things in this scenario, even if the numbers on paper seem to make sense. Numbers on paper are not equal to conditions of wear in real life.

At this point, I am 100% convinced that the only SAFE non-solar way to charge lithiums in a T1N is by using a second alternator. A second alternator is a very expensive proposition because of the mounting bracket availability issue. For the moment, I will omit those details and that research.

Rather than belabor the alternator failure details in this post, I'd encourage you to read this account of that failure below (non-monetized blog post).

Understand that if your alternator fails the way mine did, it could easily put your rig in danger, and your life in danger, because when its degradation causes the chassis battery voltage to fall too low and the computer to shut down, your T1N is just going to stop dead in the middle of the freeway, wherever you happen to be at that moment (possibly with a 70 mph big rig bearing down on you). That is what will happen if you don't catch that kind of failure in time to save yourself from an uncontrollable shut-down.

https://interstateblog.blogspot.com/2018/09/psa-alternator-clutch-pulley-failures.html
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I don't understand your chart. Both alternators.... both good and bad are charging voltages. I wouldn't replace an alternator for putting out 14.07 at 2000 rpm. It's obviously still working.

It seems you suffered a clutched pulley failure not a alternator failure. Why not just replace the pulley?

Your b2b never pulled more than 50 amps from the alternator....not exactly heavy loading of a 200amp alternator. I just don't understand your conclusions.

What are you using to measure SOC?
 

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M

Midwestdrifter

Engineer In Residence
A bit off topic, but a bad serp tensioner, or other failing belt drive part can cause alternator clutch failure. A slipping belt can rapidly heat the alt clutch to failure, regardless of load.
 
E

eslmooney

New member
InterBlog said:
I clearly DO live in Texas, and have lived here continually since 1991. As john61ct notes, it simply can't be done. Not without the kind of money that makes it a non-starter for those of us who are not independently wealthy.

Let me put it in more concrete terms: husband and I have spent around $10K on our solar, electrical, lithium, and supporting components and materials (we did our own labor). That investment gets us about 2.5 hours of off-grid a/c use at a time (when I trust the alternator to bring the battery back up timely).

The FitRV couple has published extensive analyses of lithium systems (the husband is also an aerospace engineer, like my husband). In their rig, where the entire electrical system is sized larger than ours, IIRC they get about 3.75 hours of a/c use per battery charge. In other words, even the internet influencers can't do much better than our DIY job.

That is precisely why I reverse-snowbird. I meet the laws of physics part way. We designed a system that covers us off-grid in certain limited scenarios. But for the most part, we just travel out of the heat.
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HarryN said:
I would probably not purchase a no brand alternator with essentially no reviews or detailed specs off of amazon.

Perhaps consider nations, mechman, etc. A supplier that gives real, detailed info on their alternators, such as an RPM vs current output curves.

A good quality, high output alternator will have at least 6, perhaps 12 phases, and the supplier will be providing a lot of info (frankly bragging) about how great it is and why. Designing and building a quality, high output alternator is non trivial, so the people who are good at it are recognized as such for a reason.
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Have no way to know who is the better



Here are a few that I had bin looking at.

https://www.nationsstarteralternato...Alternator-PRE-07-2-7L-p/12385-280-pre-07.htm

https://www.sprinterstore.com/product/alternator-auxiliary-kit-3-0l-for-sprinter-vans/

Bosch Alternator
Click to Enlarge
(Read reviews)
Our List Price:
$337.73
with FREE Shipping
Core Price [?]: $95.00
Quantity:
1
(5) In Stock
Part Number: 18926-08065700
Notes: Alternator - 200 Amp (Rebuilt)
Condition: Remanufactured

Shipping Options:
Free Ground Shipping
This Part Fits: Catalog: G
Vehicle
2006 Dodge Sprinter 2500
 
E

eslmooney

New member
John Haywood says

March 7, 2016 at 12:56 pm

Great writeup! I am a full timer in a 2007 sprinter based Winnebago View. I have converted to total electric, even removing all of the propane system and appliances and the generator. I have 400w of Sinology lithium, bms system, Magnum 2000w sine wave inverter and 400w of AM Solar panels and all the safety, control and monitoring stuff. I am a geek of the first magnitude! i also installed a 280amp alternator (limited to 200a max) with an external controller (Balmar). I also have a dash mounted control switch to shut off the alternator or change it’s charge rate. I run my 12v refrigerator, expresso machine, microwave, toaster oven,induction cooktop, etc. Absolutely love the lithium system. Have done entire install myself, and the removal of propane and generator too. BTW, removing all that stuff and selling on Craig’s List went a long way to offset the high cost of the Lithium system! One more thing…I also use the lithium as my chassis battery system, completely disconnected the chassis battery. This vastly simplified the charging system, and provides more than enough power for everything. (I do still have the chassis battery as a backup, but have not had to use it in a year) Additionally, I have not plugged into shore power since I installed this system a year ago. (2 other notes, l live in southern California, so there is lots of sun, and I generally drive 400 miles a week or so. The charging while driving makes up for the 400 watts of solar. I regularly charge at 180 to 200 amps with the alternator)

Wish I could talk to John to see how he making out.
Reply=
 
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OrioN

OrioN

2008 2500 170" EXT
eslmooney said:
John Haywood says what he has done John Haywood says

March 7, 2016 at 12:56 pm

Great writeup! I am a full timer in a 2007 sprinter based Winnebago View. I have converted to total electric, even removing all of the propane system and appliances and the generator. I have 400w of Sinology lithium, bms system, Magnum 2000w sine wave inverter and 400w of AM Solar panels and all the safety, control and monitoring stuff. I am a geek of the first magnitude! i also installed a 280amp alternator (limited to 200a max) with an external controller (Balmar). I also have a dash mounted control switch to shut off the alternator or change it’s charge rate. I run my 12v refrigerator, expresso machine, microwave, toaster oven,induction cooktop, etc. Absolutely love the lithium system. Have done entire install myself, and the removal of propane and generator too. BTW, removing all that stuff and selling on Craig’s List went a long way to offset the high cost of the Lithium system! One more thing…I also use the lithium as my chassis battery system, completely disconnected the chassis battery. This vastly simplified the charging system, and provides more than enough power for everything. (I do still have the chassis battery as a backup, but have not had to use it in a year) Additionally, I have not plugged into shore power since I installed this system a year ago. (2 other notes, l live in southern California, so there is lots of sun, and I generally drive 400 miles a week or so. The charging while driving makes up for the 400 watts of solar. I regularly charge at 180 to 200 amps with the alternator)

Wish I could talk to John see he making out.
Reply=
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Max charging rate for for most LI banks is 1C. Ideal charge rate is 0.3 to optimize the longevity of the bank. Charging a 400aH bank at 200A is 0.5C....
 
J

john61ct

Active member
Yes, but actually **getting** 200A continuous output is a very big challenge, even in a big old truck where there's room to crawl inside under the hood with the engine and fit a large frame 300A fire truck alternator **designed** to do so when things start to heat up.


Put a "max rated" 200A alt even on a bench in an an aircon workshop, spin it up to output anywhere near that, attach a depleted 400AH LFP bank and watch it fry, blow the diodes etc in under 10min.

With overtemp protection, may not damage the alt so much, but usually Voltage drops, so in effect no more charging!

So you need an external VR like Balmar MC-614 that scales **current** back but maintains your voltage setpoint accurately.

Newer vehicles designed to Euro standards of fuel economy and low emissions, are a whole 'nother story.
 
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john61ct

Active member
Just installing a Sterling BB series DCDC charger in between gives you the control you need to both protect your alt setup, and get the LFP charged as quickly as possible

within the context of the temperature limits
 
ecowhale

ecowhale

NC3V Campervan for Sale
john61ct said:
Just installing a Sterling BB series DCDC charger in between gives you the control you need to both protect your alt setup, and get the LFP charged as quickly as possible

within the context of the temperature limits
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I would get the Sterling if it were easier to program by way of Bluetooth or PC connectivity but it is not and apparently requires some kind of a very quirky method to program so I turn that down in favor of progressive RC iharger 406duo.
 
E

eslmooney

New member
Here more John writes

John Haywood says

March 7, 2016 at 3:07 pm

Nina, I use the Balmar MC-612 External regulator. It is programable, but not easily. I programmed it as close to Lithium parameters as possible. It is a multi-stage charger, but doesn’t really take into consideration the start -stop nature of driving an RV and charging Lithium. It does require that you rewire your alternator to allow for external control. It is rather easy, and many writeup and utube videos are available. it does have a half power mode that I wired to a switch on the dash. from there I can control full/off/1/2 charge. on the Magnum controller or my blue sky controller I can see the charge rate ( both are mounted directly above visor on the drivers side) additionally, my bms systems will alert me to potential overcharge conditions. I find that if I am driving for an hour or more that I will switch to the 1/2 power mode, dropping charge rate to 120-150amps. no sense in charging faster than that. If I am only driving for a short time I charge at 150-200amps. Also, the alternator I have is a 280 amp max with 100amp at idle. By programming the MC614 to max at 200amp it keeps the alternator cooler, and limits the charge rate to the batteries. my LithiumStorage.com Sinopoly SP-LFP200AHA batteries like around 70-80 max for each 200amp pack. They can take higher, but that does produce more internal heat, so I keep it down to 70-80 most of the time.
 
J

john61ct

Active member
ecowhale said:
I would get the Sterling if it were easier to program by way of Bluetooth or PC connectivity but it is not and apparently requires some kind of a very quirky method to program so I turn that down in favor of progressive RC iharger 406duo.
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interesting choice. pretty sure they need a very stable power supply

let us know about reliability long term

to me much more important than convenience or shiny features

but your rig your choice
 
ecowhale

ecowhale

NC3V Campervan for Sale
john61ct said:
interesting choice. pretty sure they need a very stable power supply

let us know about reliability long term

to me much more important than convenience or shiny features

but your rig your choice
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I haven't tried it yet; the person I bought my Tesla battery module from said he has tested the iCharger extensively in harsh, varied voltage conditions successfully since 2015.
 
I

InterBlog

Member
A couple of additional anecdotal comments here, for the 30,000 foot view.

I first became concerned about the alternator failure potential when journalist Brent Rose (www.connectedstates.com) lost his first *TWO* alternators. He has 200 AH lithium, 300 watt inverter, and 320 watts of solar on a 2006 T1N. On the internet where people are competing for followers and clicks, users tend to report their successes disproportionately to their failures, so you can't always take their descriptions at face value. The upfitters are doing a brisk and lucrative business predicated on the Sterling B2B as an integrated component - they don't want their customers to think that there might be a problem or hidden risk (I've tried to warn them of this - they won't listen to me). Brent was different - he was open about what happened, possibly because he was not the average DIYer whose technical reputation was on the line. He was just a journalist traveling in a retrofitted T1N.

We never did learn WHY Brent lost two alternators in rapid succession, because being non-technical, he simply had his van flat-bedded to a repair shop both times and "had them fixed". But during both failures, his T1N simply quit in the middle of the road without warning, when the computer shut down due to insufficient voltage from the chassis battery, after his alternator stopped charging it. He managed to extricate himself from both break-downs without a smash-up. He's exceedingly lucky.

Pay close attention to this next part: Brent's lithium retrofit was done by AM Solar, which is reputationally one of the best in the country. When I tell people that we lost a 17-month-old alternator, I get a lot of replies along the lines of, "Oh, you must have made a mistake in your DIY job." No, we didn't. And even if we did, there are reports of the SAME thing happening to the best upfitters. So what does that suggest to you?

Speaking of the best upfitters, please also read between the lines on what Advanced RV did with their alternators. They don't come right out and say something like, "We had X number of customers with failed alternators" - that would be bad for their business. They spin the alternator issue (pun intended) a different way, a more positive way, showcasing their a-mazing upgraded alternator into which they invested VERY heavily so that "customers would stop having major alternator problems" (paraphrased). This, too, suggests that there's more going on with alternators than immediately meets the eye.

This ARV video is worth 6 minutes of your time, if you have not yet seen it.

https://www.youtube.com/watch?v=XANYxoEF_HY
 
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