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Overkill bms charge options

Right now the pack voltage is 27.05 volts and it's clear the cells voltages have dropped a bit. I will wait a little longer, and then unplug the UPS from the grid and see if it will discharge. Of course discharge is turned on in the app.
As of now the pack voltage is 27.02 volts so I think we can assume turning charging off in the app does stop charging.
 
I unplugged the UPS from the grid and it didn't blink. So the charge and discharge on/off settings are independent of each other... (y)

I turned charging back on so I don't forget next time I plug the UPS back into the grid.

This is a very useful feature for my situation and possibly others. Very clever to have this option. I never saw it in the older version of the app.

I don't know what would happen if charging was shut off and a large amount of current was applied to the BMS. And then charging turned on or off as needed. Since the FET's act like valves and would be open when charging off, I would think it would be ok.

@smoothJoey Would you like to comment please?
 
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I was actually trying to respond to the OP's original question. He hasn't replied since his initial post. I think the issue @Gazoo is having is unique to using a UPS.
Yes and now my problem has been solved. I just have to be a little more proactive with the BMS.

Now that we know charge and discharge can be turned on and off independently of each other within the app, this information might be useful to the OP.
 
Yes and now my problem has been solved. I just have to be a little more proactive with the BMS.

Now that we know charge and discharge can be turned on and off independently of each other within the app, this information might be useful to the OP.

i’d really like to get to the bottom of your results vs mine.

would you mind assisting?
 
i’d really like to get to the bottom of your results vs mine.

would you mind assisting?
I am not sure what I can do to help you? We both have Overkills' and are using the app posted on his website. I think you have the 4S BMS and I have the 8S BMS. If you have any questions I will be happy to try to answer them.
 
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I am not sure what I can do to help you? We both have Overkills' and are using the app posted on his website. I think you have the 4S BMS and I have the 8S BMS. If you have any questions I will be happy to try to answer them.
Is yours listed/sold as single port or common port?
 
Is yours listed/sold as single port or common port?
I didnt realize yours was 8s. You’re right, I have the 4s, but I have 8s jbd 200a common port shipping to me now. Guess I’ll be more attentive when I test it this time. When I checked before I didn’t have a plan. It was just a quick impromptu test that I didn’t expect to work.
 
Maybe this was discussed or I missed something. If you have a separate charger just put a switch on it. I would not try to force a BMS to control a charger for that purpose. Tell us more about your charger?
Ampster: My situation is probably fairly unique. On my boat I have multiple charging sources (3) and many battery banks (4). I'm trying to keep them all happy and not damaged by my modifications. Thanks for everyone's input, I will continue reading them, researcing elseware and report back in a couple of months when my system is up and running.
 
Late to the party here, but...

I also have the 8s Overkill BMS, and the 1026 version of the Android app. I happened to be charging my pack on my workbench when I saw this thread. Via the app I turned off charging, and it worked. I saw the current from the two power supplies I was using go immediately to zero. This should work just as well on the 4s and 16s versions the BMS, since - based on the Overkill manual - they all operate the same.
 
I have the iphone version of the app. Exactly what feature of the app are you using to turn charging off?
On my app it has battery on/off but that turns both ports off if selected.
 
I have the iphone version of the app. Exactly what feature of the app are you using to turn charging off?
On my app it has battery on/off but that turns both ports off if selected.
I can't speak to the iPhone version. My Android version looks like this:
Screenshot_20210412-125918.png
Notice the "charging" and "discharge" switch. I touched the charging switch, and it turned off visually, and turned off the current into the pack.
 
On my boat I have multiple charging sources (3) and many battery banks
Okay, thanks for the explanation. Your system is complex and as much as I do not like to use the BMS as the first line of defense, that may be the best solution depending on how much you can program the other charging sources. My last boat was before there were viable Lithium options available.
 
I would suggest you try the newer version. The biggest plus aside from being able to turn charging on an off is all the cells voltages are displayed on the main screen. Like in the above photo. If you don't like it you can always go back.
Note that you have to uninstall one version to install the other version. I.e., you can't install over the top of the other version.
 
Thanks to Amster, Horsefly, and others. I'm getting closer to my final modifications. Please confirm that both charge and discharge can be turned off from the app. Will this essentially disconnect the pack from the loads & charging? I understand from other posts that the remaining draw from the bms should be minimal and not drain the pack at all over a 6 month storage time period. Thanks again for the help!
 
Thanks to Amster, Horsefly, and others. I'm getting closer to my final modifications. Please confirm that both charge and discharge can be turned off from the app. Will this essentially disconnect the pack from the loads & charging? I understand from other posts that the remaining draw from the bms should be minimal and not drain the pack at all over a 6 month storage time period. Thanks again for the help!
Yes, you can turn off either or both charge and discharge. There was someone that posted here recently that his battery pack drained while his RV was in the shop, even though the discharge had been turned off. I can't remember the thread, but I'm still not convinced that was his problem. I've heard there is a small drain when discharge is turned off, but I can say it isn't even enough to power my Victron smart shunt, which requires next to nothing in power. I've tried it here several times to confirm: Both the charge and discharge switches on the app do what they are supposed to.
 
Horsefly, Great! I'll be able to power down and disconnect the Lithium Overkill BMS for when my boat is inactive. I'll plan to arrive back at the dock at 50-60% SOC and be assured it will be just a little lower when it's time for the next cruise. The rest of the connected DC circuit with AGM's will continue to be topped of each day via Solar.

Thanks!
 
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