Overvoltage from Alternator Runaway Under Load

[TinkeringTurtle]

Anyone heard or seen a condition where the alternator runs away and overvolts the entire electrical system? I've had a situation twice where I'm cruising along and the full Christmas tree makes an appearance. Dash screen scrolls through messages all within about 10 seconds:

• Power steering shut down
• Transmission voltage out of range
• Fuel pump communication lost
• Stop vehicle as soon as possible
• System shutting down in 10.. 9.. 8.. 7..

There's half a dozen codes after when I scan the vehicle, all errors on over-voltage or canbus chatter (U0109, P0563, U0422, etc). Each time, I've had an ecoflow dc-dc charger running and it records an input voltage from the battery in excess of 18V. After the first incident, I left my truck's dash screen on the voltage reading and a month later (2k+ miles) when it happened again, it peaked over 19V.

My theory is something about the load with the Ecoflow charger because that's what I introduced 3k miles prior to the first incident and it's happened each time when the DC-DC charger was pulling 800W. I've never let the Ecoflow pull above 400W since then and it's not happened since. It's not like the winch was running or something similar so my guess is that Ecoflow charger might be pulsing on/off and the smart alternator loses its mind. The other possibility is the Ecoflow is betraying me and sending voltage/current the wrong direction.

I've done a few searches to see if I could find any hits, but nothing that stuck out.

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[ShadowsPapa]

800 watts, ~60 amps.
(800/13 = a bit over 61 amps. I'm using 13 volts as a typical system voltage)
That's a big pull. What would it be pulling that much?

Granted, when many things are "on" or running on a vehicle - AC, lights, radio, cooling fan, other accessories, it can add up to a lot of amperage, but why would that one item be pulling so much?

You are risking blowing a few things at that high a voltage.

One question I have is - did you connect the negative cable at the battery to the top of the IBS? Anything, any load or accessory, anything that charges or discharges a battery must be connected to the top of the IBS and not to the battery post itself.

Their install video shows it going into a Ford - but they connect that black cable to the top of the IBS in their install video.

 

[TinkeringTurtle]

It's a variable range DC-DC charger for a lithium power bank setup. It's set to only draw when the battery voltage is 13V or higher so your nominal calculation is spot on.

I don't have it wired to the IBS. It's in the territory of a winch where I have that going to the battery too. I've never heard the recommendation that accessory drain should be off the IBS so I've got some homework to do! I was a first batch adopter and all the original docs required direct to battery wiring for the "reverse charging" mode to jump start the vehicle. If Ecoflow has changed the docs, that's certainly slipped past me.

It certainly damaged some things with the voltage runaway situation, mostly LEDs that didn't survive. I was working with their tech support staff for awhile but they were no help. Language barrier was too much and there's no direct troubleshooting capability.

Thanks for pointing out the IBS guidelines. I'll look into that. This hasn't been a problem for awhile now but I've gotten so much value from the forums that I wanted to give back a little with my unique situation. Cheers!

 

[TinkeringTurtle]

Actually, I misread (more like misthought) that. I do NOT have the negative going directly to the battery. It's off the frame. Only the positive lead hits the battery posts.

 

[nanook12]

If your voltage regulator loses its ground, it can make a huge spike.

 

[J Sierra]

Max voltage for AGM battery is 14.8 V. Your batteries are damaged for sure. The alternator charges the jeep batteries at about 20 A max. My guess is that the jeep is never going to be happy, putting 60 A into a converter. DC to DC converters make large spikes on the system, computers do not like spikes.

 

[Hootbro]

These alternators do not have a built in voltage regulator, the PCM acts as the voltage regulator.

 

[fourfa]

Just in case anyone didn’t catch on, this thread was destined to be confusing because Ecoflow named their DC-DC charger ”Alternator” https://us.ecoflow.com/products/800w-alternator-charger

The subject title is capitalized Alternator, but the rest of the OP is not, and none of the replies are. Thanks a lot Ecoflow

I also suspect the spikes are due to the Alternator, not the alternator (sigh). FWIW I would dial back the charging rate on the DC-DC charger to the minimum necessary. (I have a similar system, the Renogy version, which also has adjustable max current limiting.) My typical engine-on drives after drawing down the house battery are 4+ hours - so even 10-15A is enough to fully charge back up in that time. Maybe it would be helpful to know more about the usage and loads on the house battery system.

 

[BillyP]

800 watts, ~60 amps.
(800/13 = a bit over 61 amps. I'm using 13 volts as a typical system voltage)
That's a big pull. What would it be pulling that much?

Granted, when many things are "on" or running on a vehicle - AC, lights, radio, cooling fan, other accessories, it can add up to a lot of amperage, but why would that one item be pulling so much?

You are risking blowing a few things at that high a voltage.

One question I have is - did you connect the negative cable at the battery to the top of the IBS? Anything, any load or accessory, anything that charges or discharges a battery must be connected to the top of the IBS and not to the battery post itself.

Their install video shows it going into a Ford - but they connect that black cable to the top of the IBS in their install video.

I’m not at my best when it comes to electrical. What is the IBS? Do I need to hook my winch to the IBS instead of the battery post?

 

[ShadowsPapa]

I’m not at my best when it comes to electrical. What is the IBS? Do I need to hook my winch to the IBS instead of the battery post?

Up here - not directly to the post which the IBS clamps onto -

This is the IBS - Intelligent Battery Sensor ->

Connect to one of these studs - not to the battery post below - Green circle - ok, red x - do not connect down here ->

 

[BillyP]

Up here - not directly to the post which the IBS clamps onto -

This is the IBS - Intelligent Battery Sensor ->

Connect to one of these studs - not to the battery post below - Green circle - ok, red x - do not connect down here ->

Thank you very much! Excellent information. Intelligent Battery Sensor-makes sense. I would’ve gotten lucky and installed my cable there. I thought that was just posts to install wiring to the battery, I didn’t know that it was an IBS.

 

[TinkeringTurtle]

If your voltage regulator loses its ground, it can make a huge spike.

Interesting thought. I had a problem where the infotainment screen would do a graceful power off the first 6 months of ownership. That hasn't happened in over a year now but might be a gremlin there.

Max voltage for AGM battery is 14.8 V. Your batteries are damaged for sure. The alternator charges the jeep batteries at about 20 A max. My guess is that the jeep is never going to be happy, putting 60 A into a converter. DC to DC converters make large spikes on the system, computers do not like spikes.

The last incident in the OP was about 6 months ago and the AGM has been going strong so seems the battery took both hits in stride.

Just in case anyone didn’t catch on, this thread was destined to be confusing because Ecoflow named their DC-DC charger ”Alternator” https://us.ecoflow.com/products/800w-alternator-charger

The subject title is capitalized Alternator, but the rest of the OP is not, and none of the replies are. Thanks a lot Ecoflow

I also suspect the spikes are due to the Alternator, not the alternator (sigh). FWIW I would dial back the charging rate on the DC-DC charger to the minimum necessary. (I have a similar system, the Renogy version, which also has adjustable max current limiting.) My typical engine-on drives after drawing down the house battery are 4+ hours - so even 10-15A is enough to fully charge back up in that time. Maybe it would be helpful to know more about the usage and loads on the house battery system.

That's exactly what I ended up doing. I've limited it to never pull more than 400W and it hasn't reoccurred so certainly feels related. What was triggering the spike (ecoflow pulsing on and off vs a mopar part trying to compensate for draw) is still unknown.

 

[ShadowsPapa]

If your voltage regulator loses its ground, it can make a huge spike.

Wow, that goes back decades! Hasn't been an issue since at least the 1980s.

 

[ShadowsPapa]

Max voltage for AGM battery is 14.8 V. Your batteries are damaged for sure. The alternator charges the jeep batteries at about 20 A max. My guess is that the jeep is never going to be happy, putting 60 A into a converter. DC to DC converters make large spikes on the system, computers do not like spikes.

It'll go a lot more than 20 amps, depending on SOC, temperatures, etc.
That alternator is capable of cranking serious amps under loads light winches, lighting and more. It will charge a camper battery while maintaining the truck's own batteries, run the cooling fan, HVAC, etc.

 

[J Sierra]

Max charge current for AGM batteries is 30% of capacity, for 100Ah 30 amps.

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