What’s a normal “Healthy” voltage range for a 9.5kW battery?

Hi,

I’ve had a few problems with my 4x 9.5kW batteries since install at the end of this summer (On 2x Gen3 hybrid 5kW inverters; two batteries on each).

One has already been replaced and one is due to be replaced next week (one bank of cells is “bad”). And a third one has a weird serial number “1xxx-6xxxx” (since the BMS was replaced) and displays a capacity of 2.6, 5.2, 8.2 or 9.4kW depending on how it feels on the day!), and no data showing in the app or portal for that one.

The one due to be replaced is paired with a “functional” battery and the one with no data and weird serial number is paired with the one they replaced last month. So I really can’t see what’s normal !

I know what the specs say - but what voltage range are you usually seeing on a healthy 9.5kW battery? Or battery pair?

What voltages are you seeing at the low and the high end; at “0”% and 100% ?

And what sort of split are you typically seeing between a pair on an inverter at the top and bottom ends?

I just need to know so that when it’s all finally fixed I have a benchmark. I heard <10% difference in SOC displayed is the max “acceptable”. But mine have always been far more off than that (like 25%-35%), likely due to the faults. As I’ve had these faults since install I’ve not been able to get anywhere near the full capacity out of them, due to one reaching a limit, cutting off the power to both and the other one not catching up. All very frustrating.

I should add; I’m on the beta balancer software and 3014 battery update.

Thanks in advance.

It depends on which firmware your running to what the healthy range is.
My old 8.2 pack runs to 56V while charging, rests at 53.5 and used to cut off just below 51V.
Early days but 3015 (the latest one) takes mine down to 48V which is a lot lower than I expected but that's on GE not me if it kills it over time.

Ok, thanks - what about the 9.5 battery?

Anyone?

Still on 3014. I daren’t update to 3015 until they have fixed my system. Last update bricked two batteries 😱 I see it’s available but I’ll wait till after they’ve done the replacements next week. Maybe they’ll update to 3015 when they are here.

They all should run the same as you can mix and match packs across the range.
Only oddball is the e.on 5.2

Yep but they don’t - hence the question. About normal range for a “healthy” 9.5kW battery.

On my healthy 9.5kWh battery, I consider the normal range to be 48V - 56V.

This month the lowest and highest recorded voltages are 48.05V and 56.29V using readings at the Inverter. My battery is in a temperature controlled room at about 23C ambient.

Just upgraded to 3015. Re-calib and discharged to 0% 43.98v and up to 100% 56.71
This time of year I completely fill/empty battery each day (9.5)
Going back 6 days to 3013 it was 44.64v and 54.84. This seems to be pretty similar each day.
Battery in garage.

Rubikcube

BrianHere

Great. Thanks for that. Really appreciate both of your replies.

Mine are in the cellar. Pretty constant 20ish C down there all year.

I’m seeing not much below 52.0 or 51.5 at the low end and 53.5 or 54.0 at the top: “fully” charging and discharging every day also.

Hopefully I’ll start to see a new normal very soon.

hoggy From a bit of experimenting on 3013 on a gen2 9.5 -

49V equates to 5-8% real SoC at a battery load of around 20% (600W or so). That's 3.06V/cell which seems about right to me.

People should note that the voltage level is highly dependent on battery load once you get below 15% SoC so you really need to bear that in mind.

I've been running a HA/GivTCP automation to prevent the catastrophic battery SoC crashes inherent to 3013 (as low as 45V!) and after a month or so of playing around I'm fairly confident about my figures. Might be a couple of percent out but no more than that.

Basically the automation runs if the voltage drops below 49V for more than 2 minutes which allows some leeway for timeouts/brief loads like kettle etc.

First thing it does is change the Control GivTCP Mode Option from "Eco" to "Eco (Pause)" which, provided there's no charge to the battery essentially puts the battery into idle mode. Then it sets Control GivTCP Force Charge Option to 15 which simply force charges the battery for 15 minutes.

I leave the system in "Eco (Pause)" mode and provided there's no charge to the battery then 30 minutes later the battery internal calibration routines will start running and will make adjustments to the SoC figure. These initial adjustments are ALWAYS downwards, by as much as 10% in many cases and will take 30 minutes. The SoC will stay the same for another 30 minutes then the routines run again and the figure will be adjusted by no more than 1-2%. That's the true SoC, or near as makes no odds anyway. These routines only seem to run at lower charge levels (under 20% maybe?) which I haven't explored further.

Then at some point after a timed charge I run a "sanity check" automation so check the mode is set to "Eco".

I'm actually going to set the automation to run at 49.6V (3.1V/cell) as I think that'll leave around 1kWh charge (8-12% real SoC) in the battery which would then allow me to just blip the force charge for 2 minutes instead of 15. I'm not bothered about the last kWh as with recent firmware I've learned not to rely on it actually existing 😉

Edit - when this automation is triggered on a daily basis the discrepancy between displayed SoC and "real" SoC decreases each day, which shows the internal calibration routines do work. However its a case of getting them to run, which requires an idle battery, no PV power/timed charge and a battery charge level below a certain figure (20%?)