Help with my Renogy 30amp DCDC MPPT

[uksuntimes]

Also, that temp does still seem low - it may be worth putting the heater on full and leaving the car to warm up for a while (warm up the battery), as I was finding my Renogy 200ah wouldn't charge when it was that cold, even though it was within range.

I was getting a 'low temp protection' error in the DC Home app. But I am guessing your battery is not bluetooth enabled, so you wouldn't see the error, even if it is indeed the case.

 

[uksuntimes]

(for reference, my error was triggering at about 8 degrees C according to the battery temp sensor and I had to warm it up a bit from there before it cleared and allowed charging again.)

 

[mikefitz]

The battery is sitting at 6 degrees

Recovery from low temperature protection according to specification, 5 degC. Knowing how accurate not are Renogy calibration, it could be higher.
If the battery is showing a lower voltage value than expected and won't accept current, its in protection mode..

Does the battery have communication, what's the BMS status ?

 

[uksuntimes]

This is why right now I am in the middle of installing my battery into a toolbox and figuring out some insulation / warming options.

Sounds like its time for some winter warming for your battery and see if it comes back to life.

I seem to recall I warmed up the car for about 15 minutes or so before the ambient heat also warmed up the battery enough to turn off the protection and start charging again.

 

[Craig07]

I have a Bluetooth temp sensor in my battery compartment, my battery compartment is already insulated and never goes below 3 degrees.
I've had the van running for hours, I've also had the diesel heater on previously, and the temperature hasn't changed anything.
It certainly cant hurt to try this again though..

I'm starting to think that this is either a minor problem that someone smarter than myself may point to, or a major expensive one.....

Does anyone think a battery re-calibration may help?

Think I'm going to have to buy an amp clamp to test the alternator amps and starter battery.

 

[uksuntimes]

I hope it turns out to be something simple.

I hadn't had any issues with mine all year until a few weeks ago as the UK temps / wet started dropping. Then the protection triggered and I had to get it quite warmed up to turn off the low temp protection. Until that is done, it will stay on, even if you're at 3/5 degrees. It has to get warmer to 'unlock' the error from my understanding.

So if you can open up and warm that compartment and make sure it gets to say, 10/15 degrees or something, you can at least then be sure if it is the BMS preventing the charge before chasing other paths.

Sounds like you have a good grip on things, so please only take this as ideas in case they help rather than any assumption on your knowledge or correctness

 

[Craig07]

Thanks, I'm actually trying it right now.... with the van on. ?

It's doing my head in...

Sorry Mike, just read your post.
No, it's the old-school Renogy battery without a coms port - the biggest bang for my money at the time, regret it now.

If the BMS kicks in, would it still show a green light as being fully charged on the DCDC?

Cheers.

 

[Craig07]

I'm still no further forward with this issue, and Renogy is taking far too long to come back to me...

The DCDC charger seems like it's stuck on the "boost" charging algorithm and only producing 0.1 amp to both batteries...

Does anyone know if the BMS kicks in what state the DCDC charger will show?

Many thanks,

Craig

 

[uksuntimes]

So 2 things

1- you can try editing the target voltages and the boost duration in the DCHome app. I think you tap into the DC charging device and then the little icon at the top right of the screen.

2- in the DC Home mobile app, have you tried asking in the “community” tab / area of the app?

 

[Craig07]

unless I’m missing something, great advice if I was running Bluetooth connectivity ?

 

[Craig07]

Thanks to all who commented.

Charged the battery with a 240v lithium charger overnight and turned Green at about 14v, disconnected and left it resting for a while and tested again at 13.4v.
Installed it back in the van and connected everything up and reset the shunt, and whoop, whoop we started getting a charge of between 30amp - 36amp ?.

Now, although I’m happy that I’m getting a charge and my system is working, I thought I would complete some tests to see what is going, I tested the system at start and full, then under a load, and then van running and charging. The results are a bit random and for anyone who’s interested then please see the attached.
It might also help someone else with a DCDC MPPT.

Thanks,

Craig