I will first previse this by saying I have never been a big fan of Renogy products. That said I have installed one of their
DCC50S 12V 50A DC-DC On-Board Battery Charger with MPPT. If you add the Bluetooth dongle and run the app you can get around the 25/25 amp limit. The unit does not have active cooling so it will start to limit output from the 65°C to 80°C, and shut down above 80°C. It also has the ability to trickle charge the start battery when running on solar.
The new Renogy Rego line seems to have some nice features, they always seem to be on top of trends. The price of their Rego products seems to be up out of lower cost product line. I would have a hard time purchasing a lithium battery from Renogy.
Another low cost DC to DC with MPPT is the
KISAE DMT1250 I have installed multiple of these units, including my old van. The DMT1250 has the important feature, lets you set charge rate in 5 amp increments, has lithium profiles and a also programable profiles., so you can dial it in to your battery manufactures specifications. It has active cooling, so it will make some fan noise. It has a silent mode that of course will derate output.
The output display of the KISAE somewhat of it's weak link, it kind of cycles through the pertinent data, and you need to be able to recognize that cycle, not particular hard, but for some can be. No Bluetooth options, the unit is non -isolated. This is still a strong low cost unit, support has been strong. My only downside is I would have expected some newer versions , maybe with more features. But then again, no problem with getting your ROI on engineering investment. KISAE also has a good line of lower cost charger and Inverters.
Both of those products are dual units, so yes if it breaks you loose two forms of charging.
Sterling Power has a new line of DC to DC chargers that is looking pretty good. (It should be noted that Sterling actually names their products based on current input) So a 60 amp sterling unit may use 60 amps of alternator power, but only provide about 45 amps out. Many other DC to DC manufacturers will do it the other way KISAE's 50 amp unit may have a 50 amp output, but could need up to 65 amps of input. I personally have only installed one Sterling unit no problems, I do find that they seem to cause more issues for less technically inclined people
These stand alone units work well with internal BMS batteries. Battleborn has a wide acceptance, SOK is a newer to the party, while still promoting internal a internal BMS, they are replaceable. If the BMS goes bad no need to replace the whole battery. So when we move to Victron, you have a couple of choices, they have a line of Lithium SuperPack batteries that have built in BMS's and their line of Lithium Battery Smart which will need one of their external BMS units.
If thinking of going to a full line of Victron Equipment (Inverter/Charger, MPPT, DC to DC ) the external BMS would a good match, to really go with the features Victron can bring out. While they are not a battery manufacturer, I would not hesitate to purchase a Victron battery.
I currently run a Victron Multiplus II 3000 120 inverter, it to date has done everything I have asked from it. Victron will always specify their products capabilities at max output, many times in a van environment these operating temperatures are too high and the output is derated. They do this across their product line, and it is well documented and actually not uncommon.
The Victron MPPT line , is probably the largest one in the industry. You can't really go wrong with one of their units, you just need to make sure it has the options you are looking for: voltage/current, Bluetooth, VE.bus.
The DC to DC charging line of Victron is somewhat limited, mostly you choice is between isolated (input & output grounds not tied) and non isolated (input & output grounds tied). The usual setup is their 30 amp units which again is not actively cooled. This has a operating temperature rating of 20 to +55 °C (derate 3 % per °C above 40 °C). So their is a significant thermal impact.
While the 30 amp unit is a little small they can be paralleled together, I have even seen systems that use one for low alternate output (idle) but enable the secondary unit when at full speed. They pretty much have limited features, they don't keep track on input or output current for you so no real frills. (Note: if you wanted to monitor the input and output with external shunts choose the isolated unit.)
Victron has extremally good Bluetooth support, their Victron connect App, easily lets you configure their equipment at ease, be prepared for firmware updates. The good news is the firmware is updateable, the bad news is that it occasionally* needs update.
Victron also has two of the best battery monitors, their BMV line and their smart shunt. The BMV line has an external display along with Bluetooth Phone app, while the smart shunt just relies on the app. The BMV line also sports a programable relay.
And if you want total control and data you can look at their GX product line the latest being their Cerbo GX. The Cerbo brings various inputs so that you can hook up the various Victron equipment you have, it displays it in a relatively clean manor and supports porting to their Victron Remote Management clou, to date there is no fee for using their VRM. More data on the Cerbo can be found here
https://www.sportsmobileforum.com/fo...-26801-12.html post #113
A big feature of the Cerbo would be also taking advantage of the Victron external BMS. With your BMS communicating with the Cerbo you can have the BMS taking proactive measures instead of reactive measures.
From an installers perspective, the Cerbo can get complex, but from a support aspect it can be a godsend. properly set up I can connect and view what is going on turn thing on and off, load updates. I expect even more features in the future, although Victron has admitted that developing newer hardware is taking a back seat when sourcing components , the revenue generating product will win out because of supply chain issues.
Victron also unofficially supports other external BMS units such REC and recently starting working with Lithionics external BMS units.
The choice and size of the battery will also depend on equipment you are running. If running a 2000 to 3000 watt inverter you will need not only the size or amp-hour capability to run those, but you will also need to make sure you won't exceed the max discharge of the BMS. So in some conditions where single 200 amp-hr battery may seem like a good fit, two 100 amp batteries in parallel would actually be a better fit, as the max discharge rate would be doubled with the two batteries in parallel.
While there may be some Lithium manufacturers that support mounting in any position, I would check because far more like to have the battery in the upright position.
I would tend to agree to stay away from to good to pass up deals on lithium batteries. Stick with a company that has solid background, email or call and ask questions
If I was just updating the battery and maybe going with a DC to DC charger. My primary choice would be Battleground, closely followed by SOK. (And that is only because I have installed Battlegrounds and haven't installed a SOK yet). I expect the Victron SuperPack is a good battery
If going with an external BMS I would look close at the victron battery smart. I also highly recommend Lithionics, but will say they are on the higher end both in cost and features.
For a low cost DC to DC with MPPT I still see KISAE DMT1250 as a value.
If wanted just a no frills DC to DC charging setup, probably Victron
Sterling would be at the high end.
If I am on a new build or replacing most of the existing equipment I would look at the full blue immersion (Victron)
I currently run in my own rig:
Lithionics GTX12V555A-F25-DIN-MODULE
Lithionics Advanced External BMS version 8
Victron MultiPlus-II 300 2x 120V Inverter/Charger
Victron MPPT 150/60
Victron Cerbo Gx
Alternator power will be with secondary alternator with Wakespeed controller
-greg
The Delta Flyer
Linear Mode
