Lithium battery question.

[ShuttlePilot]

Here is the data sheet on the Relion RB300 lithium battery. This is what all charging and discharging decisions should be based on as dictated by the Battery Management System installed in the case by Relion.


https://relionbattery.com/products/lithium/rb300-hp


- Eric

[SCTN]

Rick, I was hoping you would see this, we have same set up. I based mine off yours. That chart is very helpful. Thank you.

Yes, the bms shuts it down entirely. I have to connect to shore and use the black button to wake it back up. I’m going to check for a loose connection. It just doesn’t seem right. This happens all the while just using 12v. The inverter not on. Only the refer at lowest setting, entire system shuts down in 3 to 4 days and I drive it daily. I’ll report back.

[Lilnuts2]

Maybe this will help some.

https://www.youtube.com/watch?v=v5MADBMKN7Q

[rsamco]

Ummmm... Sounds like your Magnum Inverter/Charger isn't part of the problem.

Are your batteries Relion? What model (otherwise don't know your Ah capacity)? If Relion, I can PM you the name & contact info for Relion's tech support person.

Are you sure that you are not discharging battery(s) to zero? That would be my guess. What fridge do you have? Any other electrical draws? How are you measuring your batteries' State of Charge (SOC)? Hopefully you can also easily measure your +/- instantaneous current flow at the battery. You probably know that I installed a Relion battery monitor...hopefully you have the same or similar meter. It is HIGHLY recommended...I couldn't have figured out & initially tuned my van's setup without it! And IMO it is indispensable thereafter for ongoing daily monitoring & management of electrical usage.

By the way, next week I'm planning to post a detailed 1-year anniversary writeup re my entire electrical setup. It will give the tuned parameter settings for all my components.

[SCTN]

Thanks to you guys and your suggestions I’ve got a pretty good grasp on this now. My charger/inverter controller wasn’t set up properly for my specific battery’s. I have 2 120 ah expion 360 batteries, a RELiON batter monitor and magnum controller. I have to go in a set the appropriate setting in the cc/cv options menu. My charge voltage was the biggest change. I wasn’t able to fully charge my batteries before. I have on shore power to test now.

Everyone’s suggestion was super helpful and got me thinking and looking in the right spots. Thanks again. Hopefully one day I can contribute.

[SCTN]

Looking forward to that write up.

Originally Posted by rsamco

Ummmm... Sounds like your Magnum Inverter/Charger isn't part of the problem.

Are your batteries Relion? What model (otherwise don't know your Ah capacity)? If Relion, I can PM you the name & contact info for Relion's tech support person.

Are you sure that you are not discharging battery(s) to zero? That would be my guess. What fridge do you have? Any other electrical draws? How are you measuring your batteries' State of Charge (SOC)? Hopefully you can also easily measure your +/- instantaneous current flow at the battery. You probably know that I installed a Relion battery monitor...hopefully you have the same or similar meter. It is HIGHLY recommended...I couldn't have figured out & initially tuned my van's setup without it! And IMO it is indispensable thereafter for ongoing daily monitoring & management of electrical usage.

By the way, next week I'm planning to post a detailed 1-year anniversary writeup re my entire electrical setup. It will give the tuned parameter settings for all my components.

[SCTN]

Full charge. Previously it would only go to around 80%

[rsamco]

Great!

But I still don't understand (1) why your fridge is consuming ~200Ah in 3-4 days, and (2) why the Magnum charger wasn't kicking in before your batteries were fully depleted.

My Isotherm 85 Cruise fridge consumed per day ~30Ah @ ~80F cabin temp before adding more insulation and ~20Ah/day after +insulation (I'll post specifics later over in Starr's thread in this forum).

[SCTN]

Here is how I understand it. I have 240 amp hours. My controller shuts it down at around 50%, I know this because when I turn it all back on after plugging into shore power my relion meter says so. I was previously only able to charge to 80 percent. So I was using only 30 % of battery charge. ~72 ah were being used. Divide that by the amount of days and I was using around 24 ah a day. It’s been cooler here in Santa Cruz and I leave vents open so van doesn’t get too hot so sounds realistic my fridge (iso 130) set on 1 and whatever misc draws I have consumed around that. I also drive a little so a little charging going on too so hard to really dial in daily usage based off current info.

Magnum charger wasn’t kicking in because I wasn’t plugged in nor do I have full time solar panels.

That’s my explanation.make sense? Now that I have full batteries I’ll be able to see how long I get without it shutting down. I had planned on draining the batteries to 20% but after further reading it reduces lifespan. I may keep it at 50% drain limit and just plan on charging with shore power more often.

[rsamco]

OK, fridge consumption does sound reasonable. Batteries shutting down at 50% isn't.
-- you should be able to drain them to any level you want. A battery controller (aka BMS) usually just protects against overheating & over voltage. They only shut a battery down when there is an imminent threat to the battery (& a low SOC is not that). Don't know anything about Expion so can't give you any specific guidance there. Maybe your battery monitor hasn't been initialize correctly & your SOC is going to 0%?? You have to program it with correct capacity (Ah) & tell it when you have a 100% charge -- it can then keep a running account of amps out of and into the battery in order to know SOC (since it cant rely on voltage level to indicate SOC). For example, if the programmed capicity is too high, then it will still show >0% when battery is really at 0%! I find it interesting that you have two batteries and they are shutting off at a 50% monitor reading. For example, maybe the monitor is reading the current/amps in/out of only one of the batteries but it's programmed for the two battery capacity -- so a 50% reading is really 0%! Just a thought/guess.