I'm building a solar generator and I'm starting out with a 4S3P Headway system with the 15 AH cells giving me 45 AH total. Can the Overkill Solar BMS be programmed to disconnect the battery at lower max charge/discharge current? I may increase to larger batteries in the future, but I'd like to start smaller now.
Overkill Solar BMS Question
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MisterSandals
Participation Medalist
3 in parallel and each (4) of them in series? 3P4S
Yes, i have not experimented with how low it can be set but probably as low as you would need. The iPhone app that lets you change settings is $10 last i heard. Its an excellent app.
This is a little bit of an unusual question and to me, it makes me think you are trying to use the BMS for something it should not be used for.
Disconnecting the battery from your system is pretty tough on everything and should be avoided except to protect the battery (the purpose of the BMS).
What are you trying to do? Control charging? (always the job of the charge controller)
Control discharge amps? What is the use case for this?
Pierre
Somewhere down South
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You can program the charge / discharge control separately. In your case I suggest setting the max charge current at 0.3C ( 15A ) and the max discharge current at slightly over 1C ( 50A ) depending on the specs of the BMS. Install a fuse / cct breaker somewhere in line between the battery and the load to protect your wiring etc. You do not want to disconnect the battery from the BMS unnecessarily.
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Yes, just being used for protection and cell balancing. Charging will be controlled by a Genasun MPPT charge controller.
I'm not sure what you're asking... [Solar panels] > [Charge controller || Load] <> [BMS+Battery] is the use case. The job of the BMS is to disconnect the battery and protect it if the incoming or outgoing parameters exceed the set limits. I've never heard that disconnecting things is bad for the battery. It would seem to me if voltages and currents exceed their safe parameters, keeping the battery connected will do more damage than disconnecting it. Am I misinterpreting your questions?
This BMS is probably a bit "large" for this battery, but it has all the features I want so I'm leaning towards it. I've heard horror stories about Daly. And some of the other brands are unavailable or hundreds of dollars. The Overkill Solar is kind of in the sweet spot. I just want to make sure it can be "configured down" for this battery.
I'm not sure what you're asking... [Solar panels] > [Charge controller || Load] <> [BMS+Battery] is the use case. The job of the BMS is to disconnect the battery and protect it if the incoming or outgoing parameters exceed the set limits. I've never heard that disconnecting things is bad for the battery. It would seem to me if voltages and currents exceed their safe parameters, keeping the battery connected will do more damage than disconnecting it. Am I misinterpreting your questions?
This BMS is probably a bit "large" for this battery, but it has all the features I want so I'm leaning towards it. I've heard horror stories about Daly. And some of the other brands are unavailable or hundreds of dollars. The Overkill Solar is kind of in the sweet spot. I just want to make sure it can be "configured down" for this battery.
chrisski
Solar Boondocker
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I have purchased smaller Daly BMSs, 30 amp discharge 15 amp charge for less than $20 each that arrived quicker than Overkill and have worked for that small batterypack.
I do have Overkill with the app on an iPhone and is adjustable. You can download the Xian (spelling) app and it has a practice version where no battery or BMS is needed. That wold be good to be sure the settings you’re asking for work. I pretty much use standard settings and did not change much.
I do have Overkill with the app on an iPhone and is adjustable. You can download the Xian (spelling) app and it has a practice version where no battery or BMS is needed. That wold be good to be sure the settings you’re asking for work. I pretty much use standard settings and did not change much.
MisterSandals
Participation Medalist
It’s not bad for the battery but it stresses the BMS and everything powered up. Most SCC makers say to never disconnect the battery from and SCC with an array (especially energized) still connected.
Exactly which was kind of my point that your SCC and other equipment should be setup so that the BMSs limits are never reached.
So my original question was intended to see why you are hitting your BMS limits.
Ah, gotcha. No, should not hit the programmed limits under normal circumstances.
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