Charging Lihium batteries directly from Alternator

Thanks for the reply. No smart alternator here, just an old fashioned one. Would look at replacing it with one of greater output.
Cheers
Lyndon

My sparky encouraged me to charge my new (last year) under-bonnet DCS lithium direct from the alternator, but via a Victron isolator. He put twin DCS in his new Hilux. We both found that the Prado & Hilux alternators don't put out a high enough voltage to charge lithium all that quicky. He put a DCDC in mine in place of the isolator. Not sure what he did with his - he was experimenting with a modified alternator last time I talked to him. He told me that it's not a problem with the 200 series alternator. Leigh - have you check your charge rate?

Most install a booster diode into the 200 series and pre 2.8Ltr Prado and Hilux versions which solves the charge voltage issue. Unfortunately with the 2.8 you need the DCDC. With my 120 I get around 80A peak into the the car Lithium with a booster fitted. Battery is a DCS extreme recharge time from flat to full is around 1.5 hours without van attached but with van and it's two 100Ah Lithiums recharge time all up is 3 - 4 hour drive to recover car and van batteries from around 15% to 100%

Hi Leigh

Thanks very much for your info, very helpful. I have an older Troopy, so no smart alternator. I would look at upgrading to a high output should I go down the Lithium path.
Very interesting to hear how your van is only getting a trickle charge despite using quite heavy cabling.
Vd would seem the issue I would have thought. Have you measured the charge voltage at the van whist charging? Some that have to run that boost diode only get around 14.5v output, not up to 14.8. Maybe not enough potential difference once it gets all the way to the van?
Interesting that the Prado came with a temperature compensated alternator. This is why you have probably had no issues.
Also interesting to take into account the resistance of cabling in limiting current being delivered to the batteries and hence perhaps protecting the alternator to some degree from thermal overload.

Cheers

Lyndon

The issue will charging the van is lack of voltage. If the car voltage is 14V for instance then you have pretty much 14V at the aux. If the aux is low then say it has a terminal voltage of 12.9V then you only have 1.1V to charge it and with the battery under bonnet that is ok.

If however the battery is in the van then you only have 1.1V to play with and allowing for voltage drops across cabling fuses and connectors that is not much.

Lyndon,
No need to change the alternator in your HDJ78. They are 110A so plenty big enough for lithium batteries, and they are temp compensated like every other Landcruiser alternator. I see the same voltages on my 2019 VDJ as I saw on my 2002 HDJ.

Really Phil? If so, that is excellent news!
Here is a photo I took, I tried googling it. I thought it was an 80 amp from the results I got. Be very happy to prove I am wrong! Any links re the numbers on the photo?

Cheers
Lyndon

Lyndon,
Just looked up your alternator, the 27060-17250, and as you can see from this photo, it is a genuine Toyota 110A alternator.

There is no need to upgrade. It could run two DCDC chargers if needed, but they are a great alternator and will supply all the current needed .
The 80series and 75series had the 80A alternator.

Thanks Phil, takes a weight off my mind. I knew it was genuine as I've had the vehicle since new.
105k in almost 20 years :-)
Never been used as a daily drive, hence the low kays.
I wanted fast charging and to avoid having to cough up for DCDC.
Looks like I may have had a win.
I have access to a good quality thermal camera. I also have a DC tong meter.
So I'll publish some test results in a few months time.

Cheers
Lyndon

PS, did you have a Tvan at one stage?

Lyndon,
No matter what you end up having to cough up!
To get a Lithium battery that is capable of alternator charging and living under the bonnet will cost you a premium.
The vast majority of Lithium batteries will have a max charge rate. Often its around the 50A mark for a single battery but it is a number you should check. These lithium batteries actually warm up more from a fast charge than they do from a fast discharge.
My personal preference is to use a normal lead acid battery for cranking. Then use a DCDC charger to isolate an auxillary Lithium battery in the back of the Troopy. I use an Enerdrive Dc2DC charger set at 40A, and it recharges our 200Ah of Lithium very quick. But a Redarc 40A BCDC would do the same job.
I think that if you spend a lot of money on a Lithium battery, it is worth spending money on the perfect charging system which is a quality DCDC charger. The charger will also take in solar.

Hi Phil

2 x 100 lithium (and possibly 3) going in the rear of the Troopy. From what you have told me, and looking at the specs (which do mention the optimum max charge rate of 50A), I should be OK with just the alternator.
I already have a built in 100/50 Victron MPPT

Battery Type

Lynton, not sure why you're going with that battery. It effectively has no warranty because support is from the US. You can get plenty of good Lithium batteries in Australia.
I've fitted a lot of Lithium batteries for mates. If they want something very simple under the bonnet with alt charging , they get a DCS.
If they want something in the back of a Troopy, we go for a 200-300Ah battery and charge it behind a 40A Redarc or Enerdrive charger. Pick of the batteries have been Renogy and Kings, of late because I've tested them and they deliver full capacity and appear to be good quality on tear-downs. There are plenty of others out there that do not deliver full capacity but it all depends on price. One battery is sold at 220Ah but I've only ever measured 183Ah, but at the cheap price it was still good value and so far it runs 1500W inverters fine via its 150A BMS.
Battery monitoring also matters with Lithium and the Renogy often have a reasonable bluetooth app to tell you state of charge. Otherwise fit a shunt monitor (I'd suggest Victron smart shunt as you already have the Victron solar charger and they can be networked).

Hi Phil

Those batteries I linked will be sourced from a local dealer in Darwin that I know and trust, so they will sort the warranty.
Why those.
1.) I didn't to want to muddy the waters straight up, but they will be going in a boat for starting the motor and running accessories. So a good IP rating is essential. DCS don't have this. After the upcoming trip they will get moved to the car.
2.) Why this size, they will tuck in the wheel wells either side of drawer system.
3.) Warranty 10 years to %80 capacity. Think DCS is 3 or 4.

Just wondering, are you from SA and used to own a Tvan?

Cheers
Lyndon

Lyndon,
Yes, that's me. From Adelaide and still own the Tvan although we also have an offroad caravan as well. Currently driving a 2019 troopy. used to have a HDJ79 back in the day. Been on Exploroz since 2003.

Thought so. You didn't meet a couple down on the Goolwa beach with a shinny new Tvan around 2007 by any chance?

That might have been a different Tvan and different couple. Ours is a 2003 Tvan and we got it in late 2009.

Hi Bob, this is his workshop

VEOP

Good on you, Cookie, thanks.

Bob

Thanks.
From what has just been posted, I might not need it. Looks like my alternator might be good to go

Hi

Yes, I definitely plan to charge the battery within the manufactures specifications.

Voltage, max/min charge rates etc

Cheers

Lyndon

I'm no expert on the subject but if you charge directory off the alternator what is going to control and monitor the power that is going into the battery? As I understand the BMS will shut it down and protect it from possible damage if it is detected but I thought you need something to monitor it and control the power feed so it knows when to stop charging the battery and it charges it correctly in stages. Also a percentage gauge so you can keep an eye on the battery level.
You can wire an agm battery off your starter battery with a battery isolator and no charger it just won't fully change it but I wouldn't do it with a lithium unless the manufacturer claimed it was ok but I doubt any one would.

"You can wire an agm battery off your starter battery with a battery isolator and no charger it just won't fully change ".
It sure will.
I run a "standard" 120Ah AGM as a crank battery plus 400Ah of "standard" AGMs for the house.
I can connect the house AGMs directly to the 80A alternator (and the crank AGM) and fully charge the lot together at 14.4V. Lead acid batteries (including AGMs) self limit charge rate by virtue of the limit to the speed they can conduct the chemical reaction involved. As the SOC increases, the charge rate decreases unless the voltage is higher, but 14.4V is plenty to achieve a full charge.
I intend to do similar with the new build except that all batteries will be LiFeO4. As I understand it, the risk is to the alternator (overheating) not to the batteries due to the potentially much higher speed of the chemical reaction involved.
Cheers,
Peter
OKA196 motorhome

No worries just going of what I've read over the yrs they fall just short of full charge. My first 105ah agm I ran for the 3 months before getting a charger it sat around 12.9v then after I fitted a charger a 170w solar panel and a 2nd 105ah agm in parellel then it usually stayed around 13 - 13.1v.
Also the Supercharge Allrounder calcium battery I use as a starter battery was 12.9v then I wired a permanent 100w solar panel to it and is then stayed around 13 -13.1v. That is after checking the both types of batteries in the morning after sitting overnight without anything running of them until 5yrs later when they slowly started to drop in power not at exactly the same time within a couple of months of each other. Ambient temp changed thing a little as well. So I suppose an alternator can do a very good job but it can be improved on marginally.

The following link is from the manufacturer that I plan to get the battery from. Doesn't go into the depth of detail that one would like, but they don't seem to have a problem with folks using an alternator to charge their batteries.
So for some folks buying a DCDC might not have been necessary as other on here have demonstrated.

ALTERNATOR CHARGING

Will voltage drop be an issue for you with the long cable run to the back of the Troopy?

Time will tell Alby, It can usually be got around by running BIG cable if necessary. It could even be an advantage in this case should the current drawer be too high as another poster alluded to.

That test has been pulled apart on a few forums now. Like most such tests it appears to have been setup to to achieve the desired results. Also note before we start if you look at the windings of the alternator under test they are already burnt before you get to the smoke test, they have already tested their setup to make sure the alternator will overheat.

The biggest issue in the test is the alternator speeds. He stated the alternator running at 3000RPM no problem. He then went on to say at a speed of 1500RPM which is well above idling speed the alternator will overheat.

The fact is a typical car idles around 900RPM. In most cars there is around a 3 to 1 ratio between the crank shaft pulley and the alternator so we have 900x3 or an alternator speed of around 2700RPM for most vehicles which is what manufactures aim at, so stating 1500RPM is well above normal alternator speeds at idle is simply not true.

Second issue is most non smart charge system alternators are a temperature compensated type, the temperature sensor is in the alternator regulator which is actually a bit of a design flaw. The sensor is supposed to be monitoring the ambient air temperature and as the ambient air temperaure rises and falls so does the alternators output voltage. The problem though is as the temperature sensor is inside the alternator if the alternator its self gets hot then the sensor sees that as an increase in ambient temperature and reduces its output ie miss reads the hot air being generated by the alternator as an increase in the ambient air temperature. These types of alternator are basically overload proof.

The alternator Victron are using is either a non temperature compensated type as its output doesn't decrease as it heats up, this would be a very rare if such a unit exists in a car. Or more likely it is a specialised unit with either no regulator or they have bypassed the regulator to keep the alternators output at maximum output.

I have no idea as to its validity other than Victron appears to be a highly regarded company so posted it up

And one with a vested interest in selling DCDC charges.

I agree Leigh
I've seen the video before, it was a bit obvious what they were trying to achieve.
All in All, sounds like good news for me.
After I do the testing, hopefully it's no DCDC charger for me.

Cheers
Lyndon

.
The thing about 'shortcuts' is that they often DO…………… fall short that is!

Lyndon If you are saying you are intending on investing in two or three lithium batteries I think it is worth the money to pay a little more for a DCDC charger like 99% of the installations do and not take the risk
Not fitting one is swimming against the tide of the general consensus of “those in the know”

Alan a few on here have been charging Lithiums off alternators for a long time know and "do know" and it is rather insulting at times that armchair experts who have no practical experience at all relying only what they have read or been told put them down.

I started my experiment knowing it was completely l"against the flow" expecting the battery to die a quick death even though I couldn't see any reason why you couldn't. The battery has had no issues to date and just refuses to cooperate with "those in the know" as you put it..

People who really have no hands on experience shouldn't be giving adive when clearly the OP is asking for peoples real world experience.

The OP may have been better off asking what setups people are currently using successfully on done similar but if he is happy to go his own path then it can be done as long as he uses a suitable battery.

The "those who know" battery manufacturers have no problem with direct charging as long as the alternator provides suitable voltage. One would expect DCDC charger manufacturers to contradict they would be silly if they didn't push their system is better.

You can get dropin in replacements for racing cars, aircraft. Yatching people have been using them for many years but of course their is just as much disagreement their on what's best. Also small capacity crankers for cars and motor bikes are common.

.
Leigh,
Was that Followup above really meant for me (Alan or Allan)? The references to "those in the know" makes me think that it was for Alby.

Yep meant Alby

Leigh I am not in the know and my comment was in no way intended to discredit you or your knowledge
I was simply pointing out what the vast majority consider the best way forward so am comfortable to stick with that category

In the meantime we will just continue on our 9 year full-time travel with our Canter 100A rated alternator achieving this on every engine start.
4 cell 300Ah LiFePO4 battery direct connected.
Others are free to use whatever method they choose.

Good solid fact there Scubadoo,
Just the thing the armchair experts love to pull apart.
I have been out of the private sector of the trade and have lost touch with the advancements. Canter used to be fitted with Mitsubishi alternators which were taken over by the South Koreans when manufacturing pulled out of Korea and the plant went on under the "Mando" brand name, exactly the same products 2/3 the price. What brand electrics are Mitsubishi using these days?

How long does that charge rate stay at those levels, it i amazing that it copes so well, which you have proven that it does, 20 years ago running an alternator at near max output for more than 10 minutes would let all of the smoke out just like the one in the victron demo.

Not contradicting, plenty of others might do that, just asking out of curiosity.

I have no idea of the alternator brand. Never looked.
I added a Victron battery isolator in series to drop the output from the original 14.5V to a maximum 14.1V.
The charge rate starts at 90 - 100A then slowly lowers to nearer 70 - 75A over an hour or so then maintains that until the battery terminals reach 14.0V at which point the battery is always near 100% SOC.
I'm guessing that some form of alternator temperature regulation is inbuilt.

It is interesting to watch the current drop in less than 2 minutes from 70A to <5A as the terminals reach 14.1V (always 100% SOC)
Almost no extra energy is added forcing the battery to the original 14.50V.

Very interesting.
Thanks for that run down.

My prado alternator which is Nippondenso units happily pumps out 80A into my Lithiums till they are charged. Most Landcruiser alternators from 2000 and earlier will do the same.

Nothing has changed, lead acid batteries weren't designed for automotive use either. They have acid in them for one and cars metal work doesn't like acid, they don't like vibration or heat or cold either. When they were first put into cars they died a quick death as the charging systems used were a constant current setup. They then moved to constant voltage but that wasn't much better. It was only when temperature compensated regulators were developed that battery life improved.

Lithiums on the other hand also don't like heat but handle cold better. They also handle vibration better. Of recent times alternator voltages have dropped for a variety of reasons and this has made then quite suitable for charging Lithiums. Most racing cars use Lithium dropins. They are becoming quite popular with motor bike owners and now cars too. Many car alternators work fine for charging Lithiums, it just like any other battery, use one that is designed for the application. Interestingly I did a search of the net for Lithium starter battery failures and I could not find any. So it would seem purpose built units must be pretty reliable. Same for the DCS under bonnet rated batteries, they have been around for quite a few years now but I couldn't find any flood of failures of them either. I would imagine some have failed but I couldn't find anyone complaining about them.

In the US many replace their crankers with purpose designed AGM units for longer life yet here most wouldn't even consider it.

As per my previous post in this thread our LiFePO4 battery setup has survived 9 year of full-time traveling direct charging from the alternator.
The battery also start the 3.9l turbo diesel engine often multiple times a day. The alternator is still performing its job. Complicating the installation further would achieve nothing.

"Our Canter 3.9l turbo diesel truck based motorhome 100A rated alternator has been directly charging our 4 cell 300Ah Sinopoly LiFePO4 battery at 70-80A for the last 9 years of full-time travel.
I added a 120A Victron Argodiode Battery Isolator in series to lower both the original initial 100A+ charging current and the regulated 14.5V output to 14.1V at which point the battery is ALWAYS at 100% SOC regardless of the charging current.

I recently paralleled a 4 cell 280Ah EVE LiFePO4 battery as an experiment.

It is the only battery and both starts the truck and powers the home behind.

Despite the many forum doomsayers it has never skipped a beat and the smoke remains inside."

Just 4 cells Scub, no bms?

2x paralleled 4 cell LiFePO4 batteries.
No usual "BMS". The often observed 740A peak starting current would likely be an issue.
My BMS setup consists of a Victron BatteryProtect set to disconnect at 12.1V (adjustable) and battery monitor alarm at 20% (adjustable) SOC.
Never triggered except to test.
No charging source exceeds 14.1V.

Yes Leigh thats about right except the battery and auto manufacturers have worked together for about 100 years to hone a well matched pairing.
Do you remember the failure when GMH released the Camira with the Exide Pulsar, the first of the calciums tried in Australia, almost all failed under warranty because no alterations were made to the charging system. They even made a calcium battery with a second smaller battery piggybacked to the side with a switch fgor emergency starting because the RC was so small.
For some reason people think that when a new chemistry comes along, as good as the technology is as a battery that it will just drop in.
Many here have tried AGMs as crankers, me included, red top Optima. Brilliant at first but become unreliable after 16 months. I have also ran under bonnet AGMs as accessory batteries, even swapped the positions so the acc battery is in the cooler spot behind the headlight with a heat shield and none of them lasted much more than 2 years. Have since changed back to a calcium acc battery and realise now just how much better AGMs are as far as having a much lesser surface charge affect but it still suits my needs and 2/3 the price, just have to see how long it lasts, it hasnt seen any corrugations yet.

I think Scubadoo has proven something but think the auto industry is reluctant to change because of the rapidly changing industry, why invest more R&D in oil powered vehicles.

It is all a compromise, car manufactures have lowered charge voltages in recent years to improve fuel economy and to meet anti pollution requirements at the cost of battery life. Smart charge systems are the same, batteries left purposefully under charged so they can store recovered energy. Modern alternators output voltages are more suitable for Lithium batteries than lead acids.

It wouldn't take much to make alternators more freindly, remove temperature compensation and trigger float voltages on charge current. Won't make any difference though as car manufactures won't use lithium batteries as they cost more than lead acids.

Not to mention filament bulbs and steel wheels.

Couldnt agree more Leigh.
All about dollars and sales figures.

SEE VIDEO LINK