Overland Power (4 Viewers)

[Acrad]

As noted above for the EcoFlow it has specific ports for each. The Etaker has a single port so their DC-DC has the second port for the solar.

However, it is possible with any of these. That is one is simply combining DC inputs. Whether it be solar/AC->DC or solar/alternator. That is if building a system from the base components solar/alternator/AC->DC all get combined on a single bus that then feeds the battery as well as the DC loads.

FWIW, I had not heard of Etaker before @Acrad's post. I learned they have been around since 2019. The market is getting quite crowded with such companies. Competition is good but I am not sure they will all be around long term.

I’ve used it in a combined input mode off an array battery to charge a portable power station. Along with voltage cutoffs I’m sure everything else has it also include a motion sensor you can activate to only draw if the vehicle is moving and not idling.

 

[kcjaz]

Follow-up to my post #140 above:

So when I drove home from work, I set the charge rate to 800w. The voltage dropped in response from 13.8 or so to 13.3. Got home and set it back to 250 w and the voltage immediately went back to 13.8v. The alt charger app shows the power as what ever you set it to. It doesn’t fluctuate with rpm. Also the Delta 2 app shows the input power and that also steadily matches whatever the charger is set to. This tells me that it’s really just a load and sucks whatever watts/amps it’s set too and that there isn’t any magic logic that uses only the “excess” power available.

Please, someone smarter than me set me right if I’m wrong.

 

[FrazzledHunter]

Follow-up to my post #140 above:

So when I drove home from work, I set the charge rate to 800w. The voltage dropped in response from 13.8 or so to 13.3. Got home and set it back to 250 w and the voltage immediately went back to 13.8v. The alt charger app shows the power as what ever you set it to. It doesn’t fluctuate with rpm. Also the Delta 2 app shows the input power and that also steadily matches whatever the charger is set to. This tells me that it’s really just a load and sucks whatever watts/amps it’s set too and that there isn’t any magic logic that uses only the “excess” power available.

Please, someone smarter than me set me right if I’m wrong.

What was the engine RPM when these voltages were measured?
EDIT: whoops I just saw where you said the voltage didn't change with RPM. Sorry.

 

[linuxgod]

I’m not convinced the alternator will put out more power than it can at a particular RPM. I think at idle you’re pulling 800W but just draining the starting battery to compensate. Driving at highway speeds yeah it’s probably actually charging at that rate.

 

[kcjaz]

What was the engine RPM when these voltages were measured?

So it was a bit dynamic and the voltages carried by 0.1v or so but the rpm’s were idle (800ish) to 2500ish as I drove home from work in residential stop and go.

 

[kcjaz]

I’m not convinced the alternator will put out more power than it can at a particular RPM. I think at idle you’re pulling 800W but just draining the starting battery to compensate. Driving at highway speeds yeah it’s probably actually charging at that rate.

I agree. No way I’m getting 60 amps at idle on top of running truck needs. I interpret the voltage dropping with higher charger setting to mean I’m drawing down the starter battery. Like you said, the alternator does what it can and the difference is mad up from the starter battery. That will continue until the low voltage cut off.

 

[FrazzledHunter]

So it was a bit dynamic and the voltages carried by 0.1v or so but the rpm’s were idle (800ish) to 2500ish as I drove home from work in residential stop and go.

I apologize for missing where you said the voltage didn't change with RPM.
250W: at idle (700 RPM) to running (2500 RPM) it's 13.8 V +/- .1V
800W: at idle (700 RPM) to running (2500 RPM) it's 13.3 V +/- .1V

My take is that when an alternator's voltage starts to slip as you draw more you've reached the point where it's struggling and is probably starting to heat up. An alternator heating up lowers its internal resistance causing even more current to flow inside it. Soon you end up with an alternator on fire. Remember that whatever your alternator is doing, at lower RPM's it can't cool itself as well.

However, what jumps out at me is just what is the current going to your unit?
I understand that you have set the upper limit so that the unit won't ask for more than 250/800W but I'd get a power meter and measure it. That's the only way you'll end the speculation and know how much current is actually being supplied.

Here's what you don't want - I think this is the recipe for frying an alternator:

• Setting the unit to draw up to 800W
• The alternator not able to supply it (maybe it's supplying 650W) with the symptom being lowered voltage

Yes the battery may try to make up the power draw but then the alternator just tries to charge the battery. In other words, the starter battery and your portable battery just present as one composite load.

Perhaps someone can correct me if I'm wrong.

 

[kcjaz]

I understand that you have set the upper limit so that the unit won't ask for more than 250/800W but I'd get a power meter and measure it. That's the only way you'll end the speculation and know how much current is actually being supplied.

^^^Duh. So I carry an amp meter in the truck…

While parked at idle with charger setting to 250w I got 18 amps. Set the charger at 800 and got 65 amps. Increased rpm to 2500, no affect on amps.

I couldn’t measure the amps from the alternator because my clamp on meter is too small and access is hard.

I think this confirms the EcoFlow alt charger logic isn’t really doing anything to limit the amp draw except shut it off at the preset low voltage.

 

[FrazzledHunter]

^^^Duh. So I carry an amp meter in the truck…

While parked at idle with charger setting to 250w I got 18 amps. Set the charger at 800 and got 65 amps. Increased rpm to 2500, no affect on amps.

I couldn’t measure the amps from the alternator because my clamp on meter is too small and access is hard.

I think this confirms the EcoFlow alt charger logic isn’t really doing anything to limit the amp draw except shut it off at the preset low voltage.

I carry 2 of these. It was only when I could measure the inputs and outputs that I got a sense of what was going on.

ANKG 150A Watt Meter Power... https://www.amazon.com/dp/B0CT7ZC1JJ?ref=ppx_pop_mob_ap_share

 

[Boston Mangler]

FWIW, the Bluetti charger variant does locate with RPM

At highest setting, it was getting 260watts at idle and 500watts or so driving

I kicked it down to halve that

 

[Valgrind]

The only way to be sure about your power is to measure it.

That's a great feature.
I went to the website and read how you can set the power in watts to the Ecoflow from the starter battery.
Question: is that power output to the Ecoflow or power draw from the battery?
Perhaps they're the same?
The only way to really tell is to measure it with something like this:
https://www.amazon.com/dp/B07YF393ZH?th=1

I found that devices like DC chargers usually advertise their power output and not their power draw.
For example, I use a Victron Orion Tr Smart 12|24-15 to charge my Goal Zero 1500X.
It outputs 360-380 watts at 24V. That's a solid 15A.
However, the input and the load on the battery/alternator is another story.
If it were 100% efficient it wold be drawing 360-380W at 13V or 28A.
But it doesn't. It draws a measured 40A, 529W at 13V at input.
So what happened?
It's inefficient as heck and gets very hot.

Don't fry your alternator!
Be careful out there!

I thought that the Tundra had a bigger alternator that people sometimes swap out. Whats the biggest one you can get? Probably smart to upgrade.

 

[FrazzledHunter]

I thought that the Tundra had a bigger alternator that people sometimes swap out. Whats the biggest one you can get? Probably smart to upgrade.

I don't know about the Tundra. But there's more going on with alternators than top output. All top outputs are rated at a certain engine/alternator RPM and it isn't at idle. Alternators GENERALLY reach most of their peak about 2200 alternator RPM's and then proceed to their max on a rather flat curve.

There is another issue besides power delivery at low RPM's and that's cooling. The alternator's ability to cool itself will burn it up just as overloading it at a higher RPM.

With that said I'm thrilled to mention that there's a guy who goes by @FrazzledHunter who upgraded the alternator and the support wiring. He's run it for over a year and thrown LOTS of power demands on it.

REF:
Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/

 

[Acrad]

I haven’t looked… do other models have reverse power capability to charge the vehicle battery like the Etaker F2000?

ETaker F2000 The World's First 2000W Full-Scenario DC to DC MPPT Batte

ETAKER

www.etakerpower.com

 

[TheIcemanCometh]

I haven’t looked… do other models have reverse power capability to charge the vehicle battery like the Etaker F2000?

Yes the EcoFlow charger

 

[kcjaz]

Just got back from Cruise Moab. This was the first real test of my EcoFlow system (fridge, Delta 2, and alt charger). It all worked great. The only minor issue is that sometimes the devices would lose BT connection with my phone. I also had the charger plug come loose on the last day so when I got back to camp I was at 25% on the Delta 2. It was no issue though as the fridge still had 100% of its 300 WH. That was plenty for over night (ambient was pretty mild so maybe a different story at 90F).

I kept the alt charger set at 200 watts the whole trip. I kept the system running for the week ahead of CM with just a daily drive to and from work, and all of the last week while at CM. So two full weeks of use and everything was kept cold. I even used my induction burner a couple times to make sausage and eggs for breakfast. The induction burner is da bomb. So simple and convenient. Scrambling eggs took about 150 WH so was no big deal.

I need to work out a better wiring routing for the charger and Delta 2 but overall, this system is working great!

 

[lx200inAR]

I saw and advertisement that Ecoflow now has a 500w version of the alternator charger. Don't know if it's smaller, but it's a little cheaper. So maybe a better option for most people who are just now looking.

 

[kcjaz]

I saw and advertisement that Ecoflow now has a 500w version of the alternator charger. Don't know if it's smaller, but it's a little cheaper. So maybe a better option for most people who are just now looking.

Thing that would be better for most unless you had an upgraded alternator.

When I have some time I want to put an ammeter on both the cable from the alternator and the feed to the charger and see how high I can set the charger before it draws from the starter battery.

 

[FrazzledHunter]

Thing that would be better for most unless you had an upgraded alternator.

When I have some time I want to put an ammeter on both the cable from the alternator and the feed to the charger and see how high I can set the charger before it draws from the starter battery.

Be aware that an alternator's power output and ability to cool itself vary with RPM. My LC engine idles at 550 rpm once warmed up, in gear with foot on the brake. High current draw and low rpm's cooks alternators.

 

[TeCKis300]

I would be comfortable adding a 40A / 500W charging load to a stock electrical system. A good rule of thumb is not to exceed ~30% of the rated alternator output (stock 180A) or 60A of additional loads. Beyond that, the concerns @FrazzledHunter brings up are real concerns that should be headed for good alternator life. I've already gone through one alternator (likely worn regulator) at 165k miles.

Part of the challenge with additional loads is that it all starts adding up fast as it's rarely just the additional battery bank charging that we're talking about. Things like upsizing the starter battery to a group 31 adds probably a 10-20A demand on the alternator. If upgrading to an AGM starter battery with low internal resistance (which I don't recommend for a number of compatibility reasons), could represent 25-50A additional load.

Then the infinite small things we add like chargers, lights, radios, etc.

For those with greater power demands, here's a thread that provides some options. I personally added an smaller overdrive pulley for load support to primarily head off cooling issues as I often crawl for long periods in summer. I also have a trailer DC-DC Anderson which is manually engaged with Switchpros so I can control that load to sometime after all the heavy startup draws or on highways. Or if you need bigger power, the link is also in the thread to @FrazzledHunter alternator upgrade.

More Power! Alternator on Overdrive

Following in the footsteps of @FrazzledHunter and his full 390A alternator upgrade: Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/ What A smaller alternator overdrive pulley and matching belt to spin the OEM 180A alternator ~16% faster. Not...

forum.ih8mud.com

 

[FrazzledHunter]

I would be comfortable adding a 40A / 500W charging load to a stock electrical system. A good rule of thumb is not to exceed ~30% of the rated alternator output (stock 180A) or 60A of additional loads. Beyond that, the concerns @FrazzledHunter brings up are real concerns that should be headed for good alternator life. I've already gone through one alternator (likely worn regulator) at 165k miles.

Part of the challenge with additional loads is that it all starts adding up fast as it's rarely just the additional battery bank charging that we're talking about. Things like upsizing the starter battery to a group 31 adds probably a 10-20A demand on the alternator. If upgrading to an AGM starter battery with low internal resistance (which I don't recommend for a number of compatibility reasons), could represent 25-50A additional load.

Then the infinite small things we add like chargers, lights, radios, etc.

For those with greater power demands, here's a thread that provides some options. I personally added an smaller overdrive pulley for load support to primarily head off cooling issues as I often crawl for long periods in summer. I also have a trailer DC-DC Anderson which is manually engaged with Switchpros so I can control that load to sometime after all the heavy startup draws or on highways. Or if you need bigger power, the link is also in the thread to @FrazzledHunter alternator upgrade.

More Power! Alternator on Overdrive

Following in the footsteps of @FrazzledHunter and his full 390A alternator upgrade: Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/ What A smaller alternator overdrive pulley and matching belt to spin the OEM 180A alternator ~16% faster. Not...

forum.ih8mud.com

"Part of the challenge with additional loads is that it all starts adding up fast as it's rarely just the additional battery bank charging that we're talking about. "

Tell me about it LOL!
I just added a Starlink antenna. What's another 60W...