Lithium batteries discharging

[Jeremy Kessenich]

Good question, I'm not fluent enough to answer it, my only question would be if the heater is internal why would it leave the battery externally to run something internally? I didn't have the information about it drawing from itself or from the charger. Not impressed by that. Knowing what I know now I would not have ordered the batteries from ETI. No one's fault but my own.

 

[Jeremy Kessenich]

I understand these aren't Battle Born batteries we are talking about. Hublion has poor documentation and customer service. They just do. Hence why I'm looking at BB batteries documentation. Their internal heated batteries say this: "Heated Batteries and Your External Monitoring Devices: All of the power used for the internal heating function is within the battery. This means if you have an external monitoring device, such as a BMV, that power will not be recorded if or when the heating function turns on. The monitoring device will need to be recalibrated."

https://battlebornbatteries.com/wp-content/uploads/2022/10/BBHeat-Instruction-Guide-Edition.HIM_HeatedRev007_06302022.pdf

 

[homebrewer]

I understand these aren't Battle Born batteries we are talking about. Hublion has poor documentation and customer service. They just do. Hence why I'm looking at BB batteries documentation. Their internal heated batteries say this: "Heated Batteries and Your External Monitoring Devices: All of the power used for the internal heating function is within the battery. This means if you have an external monitoring device, such as a BMV, that power will not be recorded if or when the heating function turns on. The monitoring device will need to be recalibrated."

https://battlebornbatteries.com/wp-content/uploads/2022/10/BBHeat-Instruction-Guide-Edition.HIM_HeatedRev007_06302022.pdf

A couple comments to these statements - The Hublion battery in my 2023 E19 came with a Hublion manual that clearly says it has a "Heating Circuit. " I called Hublion and they said that unless it states, right on the battery label, that there is an internal heater, it does not have one! So, no internal heater for me. I was calling them because I couldn't charge the battery to more than 10.4 volts. We concluded that one of the 4 internal cells was bad, and that it was still under warranty, so they're sending me a new battery. So, documentation not good, but customer service satisfactory for me. So many brands of batteries, but most or all are made in China, to specs from whatever company puts their name on it. Battle Born batteries look very good, but even on sale right now cost $750 to $1000. My other two batteries are Dr Prepare brand, now on sale for $150 to $200, so I plan to add a third one at that price. The first two have been working well.
I think I agree with you and Battle Born that the internal heating power doesn't show up on the BVM. But am I right that it gets recalibrated each time the batteries are charged back to 100% or 14.6 v?

 

[Jeremy Kessenich]

I think I agree with you and Battle Born that the internal heating power doesn't show up on the BVM. But am I right that it gets recalibrated each time the batteries are charged back to 100% or 14.6 v?

So let's say you had it charged to 100% and the heaters kick in and draws them down to 40% but because the heaters don't run through the shunt the Victron BVM still reads 100%. You plug into shore power and let the converter go do it's thing. Let's say you can only let it charge for 2 hours and have to be on the road or whatever reason but you stop the charging before they actually are 100% charged. The Victron BVM still reads 100% even though the batteries might not be at 100%. So no, it doesn't reset itself when it gets to 100% as it thinks it's already at 100%. I've had the OEM converter stop charging on it's own before it reaches 14.6 volts, I've also had the converter or solar get it to 14.6 volts and it still doesn't read 100%. It's beyond my pay grade to explain why, I've been very frustrated with it at times, and have accepted that I believe I have to watch the voltage more than the % to understand the SOC of the batteries. So, manual re-calibration is required and I've learned from being coached that once a year I will disconnect the 4 batteries I have and charge them individually to 14.6V and hold that charge for several hours to make sure the cells get balanced using a Victron IP22 12/30 battery charger.

 

[homebrewer]

That's a very good description - exactly what I have seen. I've had to remind myself that the Victron BVM doesn't control anything - just sees the ins and outs of the shunt. It is programmed with the volume of the batteries (I think in terms of a physical volume for the watt-hours or amp-hours) and it blindly counts the in/out power thru the shunt. If it thinks the batteries are full, but current is still flowing into the bank, it just sits at 100% - current stops flowing when voltage reaches the charger cutoff, somewhere near 14.6 vdc, as I understand it. As you describe, the charging current may stop, or drop way down when you're not on shore power, and charging is only from your alternator or solar panels, so you won't be at 100%, even though the BVM says 100%. These LiFePO4 batteries are a big learning experience - I don't understand all I know about them. No wonder there's so many videos about how they work!

 

[JohnK-ESC]

So do I believe “actual research papers” or do I believe my battery manufacturer’s operating manual which recommends long term storage (several months) at 50 - 60% with full charging cycles to 100% approximately every 3 months?

John