As far as I know, the Aliexpress store I linked to is from the manufacturer. Their website: https://heltec-bms.com/
And yes, low temp cut-off works fine and is configurable.
And yes, low temp cut-off works fine and is configurable.
Finally found a LiFePO4 BMS with Low-temp Charging Protection
- Thread starter Will Prowse
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OverkillSolar
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this is what I could find: https://heltec-bms.com/
8s or 16s?GOOD NEWS: Overkillsolar.com has it in stock
Hallo Will & experts,
I would like to build a storage System with this BMS - I like the possibility of self-settings.
What about the very poor maximal A from the active balancer with f.e. big 280Ah cells from CATL.
One company in Europe told me, this will not work, therefore they add an additional 700mV passive top-balancer:
You can see here: http://www.hometronix.at/Shop/index...=71203#W4YPRD_cm4all_com_widgets_Shop_5503790
He uses this balancer: https://german.alibaba.com/product-...spm=a2700.galleryofferlist.0.0.468c1343hilW61
What do you think, will it work together with the BMS proposed here?
For storage system, but also mobilhome LEFePO4-akku.
... and in a video Will says, the focus of balancing LFP´s should be the low-voltage-balancing.
Now, as beginner, I am fully confused...
I would like to build a storage System with this BMS - I like the possibility of self-settings.
What about the very poor maximal A from the active balancer with f.e. big 280Ah cells from CATL.
One company in Europe told me, this will not work, therefore they add an additional 700mV passive top-balancer:
You can see here: http://www.hometronix.at/Shop/index...=71203#W4YPRD_cm4all_com_widgets_Shop_5503790
He uses this balancer: https://german.alibaba.com/product-...spm=a2700.galleryofferlist.0.0.468c1343hilW61
What do you think, will it work together with the BMS proposed here?
For storage system, but also mobilhome LEFePO4-akku.
... and in a video Will says, the focus of balancing LFP´s should be the low-voltage-balancing.
Now, as beginner, I am fully confused...
OverkillSolar
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You can use any TTL com port to program it with the desktop application, downloadable from my website. Pinout is labeled on the circuit board.
OverkillSolar
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I always crimp them into a single 6ga copper lug.
Sgt Raven
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I used a #4AWG Lug. It was a tight fit on the Tinned ends of the wire, and I had to file down a couple of high spots. I used a hydraulic crimper for it. If you want to lengthen the wire, Use a HD Butt Splice to #4AWG. I bought a small bag of heavy duty butt splices just for that. Then use heat shrink over the top of it.
Be careful how you arrange the 3 wires inside the terminal thinking of how your going to route the wires. I didn't and they're twisted in the wrong direction. Best bet is hold the BMS up to your battery and run the wires out to where they're going and see how you want them to lay in a bundle. You probably want 2 of the wires in the triangle of 3, to lay flat on the battery. You don't realize this, till you put the BMS in it's location. If you need a slight curve in the wires, you can do this by adjusting the length of each wire a small amount. Holding them together and making a bend will show you how much to trim from the inside of the turn.
Have you messed with the 4s 330amp BMS they list? Looks like it doesn't have low temp or bluetooth control?
RCinFLA
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If I had a problem with operating in cold environment I would insulate and heat the batteries. For about the power, or less, of a typical inverter running idling current you could keep the batteries warm enough to keep them running. This is what Mars rovers did with very limited battery and PV array capacity.
I have nothing against a low temp cutout, just would do what I could to never have it activate.
I have nothing against a low temp cutout, just would do what I could to never have it activate.
found what looks like a similar item on Aliexpress cheap BT BMS with low temp
rbreding
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That's the vendor that has notoriously had shipping and supply problems. There are other vendors of it.
thanks for the info
I've placed 2 orders with them. The first one went off without a hitch. Second go around I ordered a bunch of stuff. It said it shipped and then the shipping was cancelled It took me a couple days for the seller to respond. They claimed that the shippment was too expensive and the package was returned to them, I asked for a new tracking number and they gave me the tracking number of my first order (insert eye roll). After pressuring them they shipped my stuff via DHL air and I got it all within a week.
Allright so I am thinking of ordering this BMS to work together with my 4*200ah cells.
I will be using it in a RV and it will charge through 300 watt victron mppt solar charger and through the vehicle alternator when driving.
Normally it is recommended to use a charge booster (battery to battery charger) to charge using the vehicle alternator. If not, your alternator might be using itself 100% to try to charge the battery asap. Therefore they recommend a 30a charge booster (So that the battery charger at maximum 30a and not using the alternator for 100%).
Now my question is:
- Can you set the maximum charge rate on this BMS (using bluetooth).
If that would be possible, I guess the charge booster (in this case more limiter) is not needed. Am I right?
I will be using it in a RV and it will charge through 300 watt victron mppt solar charger and through the vehicle alternator when driving.
Normally it is recommended to use a charge booster (battery to battery charger) to charge using the vehicle alternator. If not, your alternator might be using itself 100% to try to charge the battery asap. Therefore they recommend a 30a charge booster (So that the battery charger at maximum 30a and not using the alternator for 100%).
Now my question is:
- Can you set the maximum charge rate on this BMS (using bluetooth).
If that would be possible, I guess the charge booster (in this case more limiter) is not needed. Am I right?
A DC-DC charger is used, but not for the reason you stated. You're not going to burn out your alternator trying to charge the RV battery. The number of amps you're getting at the RV battery from the tow vehicle's alternator isn't much. You'll be lucky to see 20 amps on that circuit, and usually much less, with a good drop in voltage.
This is an ongoing discussion on the Ford Truck forum. Two guys that know what they're doing (one is a professional RV technician) have experimented with the circuit from the tow vehicle and the summary from one of them on how much power is getting to the RV battery is, "That’s pathetic."
The circuit that provides 12v power at the 7 pin connector simply doesn't provide much power. That's why a DC-DC charger is used. It bypasses that circuit on the tow vehicle. If anything is going to burn out your alternator, it's the DC-DC charger. I say that somewhat in jest, because the DC-DC charge is going to pull a heck of a lot more amps from your alternator than the 7 pin circuit will.
All this is predicated on a modern tow vehicle. Like a pickup truck built within the past 10 years. If you're talking about a motorhome, all bets are off.
I don't know motorhomes. I know pickup trucks. You would have to measure both the amps and the volts going into your house batteries from the alternator feed. Discharge the house batteries as low as you're comfortable with and then fire up the engine while measuring the circuit.
I'm still not convinced that you'll burn out your alternator. I suspect that the motorhome has protections on that circuit to prevent it from pulling too many amps from the alternator.
This BMS will let you set a cell & pack overvoltage limit cutoff and Release value, as well as charge over current value
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