ironridger
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If your app from your charge controller shows everything going on with batteries do you need a shunt monitor?
Shunt necessary?
- Thread starter ironridger
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SamValiant
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The charge controller shows what's going into your battery, the shunt is really used to monitor what load is coming out and is generally more accurate.
John Frum
Tell me your problems
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Imagine your car had no gas gauge or odometer and you just kept track of your fill ups.
No for me. I don't see the added value. Close enough is good enough for me.
chrisski
Solar Boondocker
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The shunt shows me the SOC of the battery and also the amps drawn from the battery. The SCC shows me how much power is being produced.
At night, I can use my most power with the Propane Blower Fan blowing. The SCC does not track that at all. The shunt tracks it very accurately.
At night, I can use my most power with the Propane Blower Fan blowing. The SCC does not track that at all. The shunt tracks it very accurately.
MisterSandals
Participation Medalist
My bluetooth Overkill BMS does this for me.
chrisski
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Thanks. I’m about two months out from having my Overkill BMS installed on the two 24 volt batteries with Eve Cells I’m building. I did not even know the BMS could do this.
Does the overkill have a way to “network” together so I know the total amphours for the two battery packs without bouncing back and forth? If it doesn’t, that may be the only reason to add a shunt.
Isn’t that what everyone does?
I have been tracking my Victron shunt vs. the Overkill BMS for several months. The Victron does a much better job. For most people, the BMS is probably plenty good enough. But after a couple weeks of partial charges and not resyncing to 100%, the Overkill has been as much as 15% off. The Victron drifts too, but after a couple weeks was still within 5%
If you reach full charge every few days, there is little difference.
The Victron adds some relay outputs that can be activated on SOC. So you can turn something or other on or off at certain points, or have an audible alarm as a certain level. If you have multiple batteries in parallel, the Victron would show the total for all of them.
Both the monitoring of the Victron or the BMS are *VERY* different from using your charge controller. Your charge controller knows how much power it is producing or has produced. It doesn't know how much of that power went into your battery vs, powered a load. It also has no idea what is consumed from the battery when the charger is not charging.
If you reach full charge every few days, there is little difference.
The Victron adds some relay outputs that can be activated on SOC. So you can turn something or other on or off at certain points, or have an audible alarm as a certain level. If you have multiple batteries in parallel, the Victron would show the total for all of them.
Both the monitoring of the Victron or the BMS are *VERY* different from using your charge controller. Your charge controller knows how much power it is producing or has produced. It doesn't know how much of that power went into your battery vs, powered a load. It also has no idea what is consumed from the battery when the charger is not charging.
MisterSandals
Participation Medalist
No way to network that I know of. I have to disconnect from one and reconnect to the other.
John Frum
Tell me your problems
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I bet you have an AAA card
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chrisski
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I think in my case, I will keep the shunt where it is to measure the health of both battery packs. I can see with me monitoring two more devices for the BMS, that will be a lot of switching between apps. If I’ve got time this winter, I’d like to see if I could come up with a way to monitor all that on a master console. My daughter writes apps, and I’d ask for help from her.
I am building a new battery (8S, 24v, 55AH, 60280 cells) for my boat. My current batteries have a Daly BMS with bluetooth connection, so I can always check SOC with my Android phone. There is a BT dongle available for the BMS I am using on the new build, but from what I read, it doesn't work well and I would like something more reliable. (Even the BT on the existing batteries is flaky.) I would like to connect a shunt and wire that to a meter on the dashboard of my boat.
Can someone please recommend a shunt that would work to provide this information? Am I overthinking this or on the right track?
Can someone please recommend a shunt that would work to provide this information? Am I overthinking this or on the right track?
MisterSandals
Participation Medalist
I would be wildly surprised if you can get an SDK from a "foreign" developer. Of the dozens of SDK's i've requested, i only received one, and that was after i reverse engineered the API and produced something useful.
If she is successful, please post it here, there are a lot of talented folks here!
MisterSandals
Participation Medalist
The Victron BMV-712 shunt has a remote meter (wired) you could mount on your console.
That looks like what I had in mind, but $206 was rather eye-opening. :O
I've only got about $400 into building the battery, including the cells, BMS and the case. Might have to come up with some other solution.
Renogy offers what appears to be quite similar for $89. Any particular reason to go with the Victron? I should mention that this system should never see more than 40 amps going through it at any time. (Never mind, the Renogy model only works with 12v systems.)
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MisterSandals
Participation Medalist
Thats what the Cadillac solution runs.
There are many other shunts with meters. I don't have experience with other shunts but think there are quite a few in the (i'm guessing here) $30-$100 range.
Super Cheap Shunt Wiring Question
I want to measure (don't need to be super accurate, within 5-10% is good) the Watt Hours that I can get out of my 55Ah LiFePO4 in my trailer, but am too frugal to pay for an obscenely overpriced shunt/meter. I ordered an under $20 set, and this is the wiring diagram: So my question has to do...
diysolarforum.com
Bob B
Emperor Of Solar
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I would just caution to make sure whatever you choose has a rating to handle a marine environment. The console on my boat is somewhat protected, but is still at the mercy of the elements ... not sure how protected your console gauges will be.
