highwaypirate
New Member
12, 10 and 8AWG marine-grade cables. I do not see any manufacturers print on the insulation, though it is the same type as my 2AWG jumper cables.
(Looking for) MPPT with Bolt/Ring Terminal Screws
- Thread starter highwaypirate
- Start date
seneysolar
Solar Enthusiast
Looks like the Morningstar only has 2 battery profiles. Flooded and sealed. If you cant work with those voltage settings then its out.
If you want custom battery settings, may want to look at the Midnite Kid 30a MPPT
highwaypirate
New Member
Either way about the Victron, it is entirely out of the question for my build. Its terminal 'screws' are stripped and would not hold anything down at this point.
Darn, it looked so promising too! I'll do some research in the Midnite Kid one, though I couldn't see their terminal connectors from their images (it kind of looks like a solder point?).
seneysolar
Solar Enthusiast
The Kid connections are inside, then they have a strain relief nut on the outside case for the wire. The marine versions are intended for vehicle applications.
highwaypirate
New Member
Hang on... that link you sent seneysolar shows its charging profile: flooded @ 14.1V and sealed @ 14.4V, with a reconnect at 12.6V. Wouldn't the flooded setting also work on the LiFePO4? (aside from it trying to equalize, that would be a concern). My CanadaProof is set to LTO settings because it stops at 14.0V.
seneysolar
Solar Enthusiast
Sealed is 14.1 that should be fine but i dont know your batteries.
Equilize is only on the flooded setting, not sealed.
If youre good with 14.1 go for it
Equilize is only on the flooded setting, not sealed.
If youre good with 14.1 go for it
highwaypirate
New Member
You are a life saver! I'm giving it a try. Thank you!
seneysolar
Solar Enthusiast
Report back with results!
seneysolar
Solar Enthusiast
Dont forget they are only 20A, youll need 2 of them with the panels in your profile.
highwaypirate
New Member
I will need three of them; I also have a 200 watt panel slid under my roof liner.
For future reference there is a wire box available for the Victron controllers that covers the screws so it is touch safe but also adds strain relief to the wires outside of the terminals connections so the wires wouldn't pull out even if the terminal screws weren't tight.
mikefitz
Solar Wizard
- Joined
- May 28, 2020
- Messages
- 2,979
The shop is not used to installing Victron products. DIY or use a shop that knows how to wire stuff up.
Your BMS is not faulty, who told you this.
Lower the charge voltage to 14.0 or even 13.8 volts. Your battery has unbalanced cells and the BMS is cutting off the charge path , this is very common for off the shelf batteries.
Idealy you want the battery to experience a charge voltage below the point where the BMS detects cell overvolts. Set up a longer time than normal for charging. Do this by setting a long absorbtion period or float volts equal to charge volts.
After several days review the situation .
This is down to installer damage , not the unit itself. Maximum cable size for the 100/20 is AWG 10.
It seems you are considering PWM charge controllers. Apart from the fact that you will lose a percentage of available panel power, ( if high voltage panels or series low volt panels you will lose up to 50% or more), you will not have ideal charging settings for your lithium batteries. This is definitely a significant degrade of your system. There is also some concern that PWM chargers may cause long term damage to lithium batteries.
Mike
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chrisski
Solar Boondocker
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- Aug 14, 2020
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Especially for the off-roading you're describing, I recommend getting a controller that will allow you to charge and float at what you want and not use a "standard" charge profile.
For me, 14.1 flooded lead acid would be good IF equalization could be disabled. Many "standard charge profiles" enter equalization automatically once a week for an hour. This is 3.525 per cell.
14.4 is a 3.6 volts per cell and a little too close to the 3.65 limit. Drifting out of balance becomes more likely with a high charge voltage.
I take my fifth wheel off road, but not like you're describing, and I set lower limits in case something happens. I prefer a lithium charge voltage of around 13.9 volts, or 3.475 per cell. That's 95% capacity. I've had a cell connection come loose and be unbalanced. Between monitoring individual cell voltage, and charging 95%, I caught the overvoltage cell and this prevented a runaway cell.
I've heard of faulty charge controllers spiking to 16.0. I would expect the higher you charge and the more often its done the voltage would drift and a single cell would exceed BMS cell voltage and shut down.
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I am on the Victron Band Wagon and they are not that hard to install, especially if the everything else is in. This would secure terminals:
There's not a lot of money in RV and vehicle solar installs and it's hard to get someone to do a good job at it for that amount of money. Especially if the build is tested and QC'd prior to delivery.
seneysolar
Solar Enthusiast
The "sealed" profile is 14.1, theres no equalization when set to sealed. Should be fine.
The OP is set on a controller they can use screw/ring terminals.
So without resorting to Amazon/China specials, we seem to be left with the Morningstar PWM. (Victron and Midnite that are still manufacturing PWM controllers too!). They work great for small systems. Im currently experimenting with a Midnite Brat and i cant tell the difference between it and my Victron 100/30 other than i had to parallel the 2 panels instead of series. That thing is kicking but so far and the Brat is outdoor rated. I think the victron will just go on the shelf as a spare at this point.
https://www.victronenergy.com/accessories/mppt-wire-box-tr does this already. They do a bad job of showing that is what it does but it includes bolts that fasten down plates over the cables compressing them making it nearly impossible to pull them out.
I didn't want to point this out but since you brought it up this seems to be the main issue and then blaming it on the product when they don't seem to know what they are doing. Also the fact they didn't know Victron has an accessory for those that feel it is needed to fully secure the cables in a high vibration environment is also indicating they are not familiar with Victron products.
I love Victron stuff but I’m not a fan of the terminals. That being said, they can absolutely be used if done correctly. I installed a DC to DC converter in an aluminum bass boat years ago. That driver knows one speed and the boat has plenty of airtime. My kidneys may never be the same. Boat trailers don’t ride smooth either. That’s been a few years now. The cables were 8AWG fine strand marine (Ancor). While the terminal was being tightened up, the cable was gently orbited to help the strands settle in. This makes a big difference! Cable clamps were used a few inches in front of the unit and along the route. A dab of Shoe Goop helps keep the cables from moving within the clamps. Zero cable movement to the Victron. A few days later a retightening of the terminals was made. It wouldn’t hurt to do a biannual inspection of every terminals and lug of anything mobile.
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McKravitts
Solar Enthusiast
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- Sep 8, 2022
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- 534
If you do use ring terminals put a drop of Loctite or equvalent on the threads. The screws can vibrate loose under the conditions you're describing.
highwaypirate
New Member
With a bit of dumb-luck, I found ONE MPPT that does use ring terminals and is also compatible with DC/DC charging. I'll disregard following this thread now, since I get heckled a lot. Thank you for all those who have made recommendations!
