Not much to say about the BMS; it's just there. I assume it's working. using the batt-go cell monitor I'm usually within 10 to 14 mv. if you make a single battery (2s4p) with one BMS your overall current could be very high. I split my bank in to two batteries. using two BMS effectively cutting the max current from each battery in half and 'derating' the BMS. shouldn't ever see more than 100 to 125amps out of either battery.
Who's using DIY LiFePO4 batteries in Rv's?
- Thread starter Tball
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KG6S
ELI the ICE man
Shown: Panels, 24V CALB system, 12V Fortune System
Tball
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Love this! Why the 2 solar charge controllers?
KG6S
ELI the ICE man
The second feeds the 24v to 12v. I got a spanking hot deal on each one...I can also use it with my panels if the need arises. I like redundancy when boondocking.
NEWYORKHILLBILLY
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I like to build this also. I am new to the game and am still learning .does that daily bms have a low temperature cutoff? I assume thats a cell balancer in picture. I probably only build one of these whats a good cell balancer that would work .
RV Truck Camper
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For the truck camper I've decided to use 195AH BLS cells. Two loops, one 120amp BMS goes to the truck campers 12v system, solar charger and the converter. The other loop uses a Victron 220amp battery disconnect, 250amp inline fuse going to a 3000watt GoPower inventor. The inventer is wired to a second transfer switch which goes to the primary transfer switch powering all the 110 plugs.
Tball
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So you have one solar charge controller charging your lithium and the other charging your 12v flooded? I think thats what your saying?
none of the daly BMS's have low temp cut off. I have a pair of victron SCC's however and they will not charge below their (configurable) low temp setting. (temp comes from BMV-712) I also have a pair of heating pads on the side of each battery that do a great job of warming up the batteries and which I am going to use for cold weather. currently working on a modification to use the external relay on the BMV-712 which will turn the heaters on / off between 40 and 65 degrees. not quite got all the parts yet. plus I'm going to have to simulate colder weather.
NEWYORKHILLBILLY
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It appears the new smart daly bms do have low temp, but i have t confirm that. I also have the virctron SCC and 712 battery sensor . my concern is that the Victor will shut off solar charge only and if i happen to plug in to power it would still let converter charge. Maybe i could just put a switch on teh converter charge line. But love for the BMS to have a low temp shut down.
Tball
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Very interested to see how this works out. I would love to see the Victron SCC have more amenities like cold weather turn off as well.
I totally disconnected my converter. my inverter is a combo inverter/charger (charger section currently turned off) but it is easy enough to turn it on if I want to charge for a bit from shore power or from a generator on cloudy days.
KG6S
ELI the ICE man
No low temp cutoff on the Daly. I rely on the Victron Battery Sensor to feed temp data to the SCC. Will has lots of videos on this. Also, I'm careful to not use an alternate charger when I expect freezing temps.
KG6S
ELI the ICE man
Both are LiFePO4 batteries. I freed up a lot of maintenance hassle on the 12v side by going LFP.
Hello Tball,
Seems like we are in the same boat.
They shipped my batteries from China few days ago and I am trying to order BMS.
So you think we will need only one BMS for the set up?
Daly 200A will be sufficient for all 8 cells?
Man this is harder than ordering my 5th wheel.
Tball
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I'm with ya on how hard it is to get a BMS, decided to change my setup and just make 2 x 12v banks so I'm going to get 2 x 120A BMS from Overkill Solar on amazon. I don't feel like waiting 4+ weeks from China as I'm getting back from an 8 month deployment here in a couple of weeks and the family is ready to go camping. @HomeTownHockeyFan has helped me out and he has a good writeup on his installation that i'll closely mirror. I just want to be waiting on the batteries when I get home and i'll just use the crappy AGMs that came with my rig until my batteries come. If I wasn't rushed I would just go with some Daly 100Amp BMS's as I'll never camp in freezing conditions and my batteries will be inside the rig as well.
