Your Battery Monitor, Smart Shunt or BMV might be giving you the Wrong State of Charge | Here is Fix
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- เผยแพร่เมื่อ 13 เม.ย. 2024
- Ever had your power go out or get a low voltage alarm when you think you have plenty of power? Here are a few ways that can happen and how to fix it.
I find that if load is around/under 200watts for extended periods (2-3 days), my BMV SOC can lose accuracy. However, if I can reach full battery charge and 100% every day and then see absorption and then float, I see improved SOC accuracy.
Shawn, I have a SOC related question. I have (2) 206 Ah SOK batteries in parallel monitored by a Victron SmartShunt. It currently reads 100% SOC with a 13.81 V and 0 Amps. When I connect via BT to the BMS of each of the SOK batteries I get 100% SOC on one battery and 79% SOC on the other battery. Both BMS's show 13.8 V and 0.0 A. Any idea why the discrepancy between the BMS SOC readings? Does the SmartShunt measure SOC of both the batteries since they are in Parallel? Love your channel!
One of the SOK batteries could need internal balancing. Re start bulk charging and watch that lower SOC battery. See if it becomes full.
Great video. Being that you are a Victron dealer, any idea when the 48v 5k Multiplus gets its UL rating? That has been pending now for almost a year.
Nope, we don’t get much advance info.
Why would I get a discrepancy, or conflicting/different readings IE: 14.2 at the shunt and 13.9 from the Multi dongle? Also, SOC stays up, and voltage drops to low cutoff prematurely when boondocking
Are you on lithium or lead acid? The dongle will sometimes report a lower voltage. We’ve seen it.
@@sotasolar 800ah lithium (8x100)
We spoke to you awhile back and you helped with cleaning the current sense on the multi 3.5mm jack
@wdafchuck oh, I remember now. Verify with a multimeter where the voltage is getting to. Could try and raise the absorption voltage to 14.4 if the dongle is reading low, it can affect the charging characteristics. You can also look into a warranty replacement on the dongle. I had a customer a while ago who needed to that.
@@sotasolar will do as soon as we get back into town. Thanks again !!!
You didn’t mention internal battery heaters with soc in the other direction. You may think you’ve got 15-20% left but you are almost at zero.
That’s a good point. Most heaters late only heat from incoming cu and don’t self deplete, however that can be the case.
@@sotasolareither method is bad. With self heating it’s using up power that the battery monitor doesn’t know about. Battery monitor SOC stays the same but there could be as much as a 5amp load in the battery depending on battery. Then if it only takes it from the charge source, the bmv will count that as charge current and increase your SOC but in actuality the SOC hasn’t change as not REAL charge current is getting applied.
Off topic question, have you heard anything about the Cerbo beta you showed a few months ago coming to final version release?
It continues to improve there is a lot of work still to be done. The community forums have the most updated information.