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[rayrokni]

hi. i’m new to all this, so please bear with me.
i got a promaster 2500 and need to install house batteries. i don’t stay in one place, i’m always moving and therefore don’t want to install solar panels to feed batteries etc. my plan is this, please let me know if this makes sense:
the mpp all in one 12v 1000w inverter unit. comes with ac input and output, and solar input.
sok 206ah battery (i may get 2)
12v dc fuse box and all the necessary bus bars, switches and in line fuses.
the mpp unit has ac input to charge batteries and solar input. but no input from van starter/battery. so my question is this:

can i use a dc to dc charger and write it from van battery to the solar input? if so do i need to be able to get a chargers that has adjustable amp output?

if i can’t do this can i just direct connect the dc to dc charger straight to the batteries? would doing this cause issues with the mpp all in one unit?

or should i just go with a 20a dc to dc charger to the batteries, a separate inverter, and not use the mpp all in one unit?

i’m just going to be running:
12v dc: led lights, mini fridge at times, usb charging bank
120v ac: small power tools and maybe at times charging 100.8v 1800wh electric unicycle at 5amps.

thank you

 

[MisterSandals]

can i use a dc to dc charger and write it from van battery to the solar input? if so do i need to be able to get a chargers that has adjustable amp output?

Yes, I've installed a Victron Orion 30A charger for a friend. In the pillar behind the passenger seat, near floor level there is a power access point that is fused 70A. If you remove the lower plastic cover you will find it easily. The trick is that it has a weird connector on the positive that I had a hard time definitively identifying so i cut it off and crimped on a lug.

Rear power ports and wiring.

www.promasterforum.com

 

[rayrokni]

Yes, I've installed a Victron Orion 30A charger for a friend. In the pillar behind the passenger seat, near floor level there is a power access point that is fused 70A. If you remove the lower plastic cover you will find it easily. The trick is that it has a weird connector on the positive that I had a hard time definitively identifying so i cut it off and crimped on a lug.

Rear power ports and wiring.

www.promasterforum.com

hi. thank you. can i not just wire it to the van battery under the driver feet, where the battery is? thank you

 

[MisterSandals]

hi. thank you. can i not just write it to the van battery under the driver feet, where the battery is? thank you

Yes of course you can. Maybe you can find and use the 70A fuse in that compartment if that is convenient.

It was super convenient to use the existing fuse and wire back to the pillar for my use. Forgot to mention there was also an IGN power source on the 15 pin connector. It appeared to be wired upside down so that labeled pin 1 was IGN instead of 15. I did not use the IGN sources because the Victron Orion has a smart sensor that detects the increased voltage when the alternator is running. Many other DC-DC chargers require the IGN source to turn on charging.

The Victron 30A model is easiest to find but there is also an 18A model that for some reason takes a little bit of sleuthing to locate (even on Amazon).

 

[kenryan]

A 206 amp hour lithium battery is probably capable of accepting a 100 amp charge rate. If you install two of these batteries, then probably 200 amp charge rate (check the battery specs). This makes your considered 20 amp B2B charger seem very small. I would be hoping for considerably more charging power than 20 amps.

I suggest researching the alternator and determining how many amps you can pull from it for charging your house battery, and then match your B2B to that number. Keep in mind that some B2Bs have programmable output limits, and that if you pull too many amps for too long, you could damage your alternator.

Because you plan to charge off your alternator and do not plan to install solar panels, I don't understand why you would want an inverter with an mppt charge controller.

 

[mikefitz]

My advice is not to get an 'all in one' but a separate AC charger and inverter. Use a DC to DC battery charger like the described Victron Orion 12 12 30.
Reconsider solar with its own dedicated controller if you will be in the van for long periods, this could result in only needing one battery rather than two, and also no need for an AC charger.

Mike

 

[rayrokni]

A 206 amp hour lithium battery is probably capable of accepting a 100 amp charge rate. If you install two of these batteries, then probably 200 amp charge rate (check the battery specs). This makes your considered 20 amp B2B charger seem very small. I would be hoping for considerably more charging power than 20 amps.

I suggest researching the alternator and determining how many amps you can pull from it for charging your house battery, and then match your B2B to that number. Keep in mind that some B2Bs have programmable output limits, and that if you pull too many amps for too long, you could damage your alternator.

Because you plan to charge off your alternator and do not plan to install solar panels, I don't understand why you would want an inverter with an mppt charge controller.

at first glance i thought great just one unit to do everything, and if i decide to add solar at a later date then the connection will be there. but then i realized there is no input for connection to van starter battery. so i thought if i could stay with this setup for possibly adding solar at a later date and meanwhile use a dc to dc charger and connect it to the solar input on the mppt.
most of the time i would be charging using the shore input on the mppt, either to a generator or home outlet.
it looks like it may just be easier to use a 30amp smart dc to dc charger. to the lithium batteries and then an inverter for my 120 needs. the van has 60amp alternator but i have to find out if it’s a smart alternator or not. it’sa 2021 promaster 2500.
thank you

 

[John Frum]

My advice is not to get an 'all in one' but a separate AC charger and inverter.

My advice is to get a low frequency inverter/charger with integrated transfer switch.
Especially if you will be using lifepo4 batteries.
This is a good one. https://www.donrowe.com/samlex-evo-1212f-hw-pure-sine-inverter-charger-p/evo-1212f-hw.htm

 

[rayrokni]

My advice is not to get an 'all in one' but a separate AC charger and inverter. Use a DC to DC battery charger like the described Victron Orion 12 12 30.
Reconsider solar with its own dedicated controller if you will be in the van for long periods, this could result in only needing one battery rather than two, and also no need for an AC charger.

Mike

yes, the more i am thinking about it the more it looks like to go with separate units for my case use. thank you

 

[rayrokni]

Yes of course you can. Maybe you can find and use the 70A fuse in that compartment if that is convenient.

It was super convenient to use the existing fuse and wire back to the pillar for my use. Forgot to mention there was also an IGN power source on the 15 pin connector. It appeared to be wired upside down so that labeled pin 1 was IGN instead of 15. I did not use the IGN sources because the Victron Orion has a smart sensor that detects the increased voltage when the alternator is running. Many other DC-DC chargers require the IGN source to turn on charging.

The Victron 30A model is easiest to find but there is also an 18A model that for some reason takes a little bit of sleuthing to locate (even on Amazon).

i believe this is the one you mentioned, correct?

Victron Energy Orion-Tr Smart 12/12-Volt 30 amp 360-Watt DC-DC Charger, Isolated (Bluetooth) https://www.amazon.com/dp/B07ZKG396Y/ref=cm_sw_r_cp_api_glt_fabc_1MT56SYRHWMK5VEBMFPZ

 

[kenryan]

Wow, 60 amps is really wimpy for a modern van. In contrast, a Ford Transit comes standard with a 240 amp alternator, with the option of two 240 amp alternators. Given your unfortunately small alternator, I agree with your decision to limit your B2B to about 20 amps.

I would expect that your alternator is indeed a smart alternator, but the B2B should be designed to deal with that, and yes you can (and should) connect it directly to your house batteries. I would avoid the built in mppt and add a separate solar charge controller if you later decided to add solar.

You are also smart in limiting your consumption. That 20 amp charge rate will not support a lot of big loads. But for what you listed in your original post, you should be able to get by, considering you drive a lot.

One of your questions was "do i need to be able to get a charger that has adjustable amp output?"

The answer is yes, if the charger is capable of more than your batteries (or alternator) can handle. It seems like your alternator should be able to handle the 20 amp B2B. If you get an inverter/charger or a separate 110v charger that is capable of more than about 100 amps, then it should be programmable. Most lithium iron batteries can accept a charge rate of about 0.5 of their capacity. So your planned 206 AH battery could probably accept about 100 amp charge rate (check specs for your specific battery). If the charger output is less than the maximum charge rate for your battery, you are good. If the charger output is more than the maximum charge rate for your battery, then you need to be able to limit it.

 

[MisterSandals]

the van has 60amp alternator but i have to find out if it’s a smart alternator or not. it’sa 2021 promaster 2500.

My recollection was that the standard alternator was ~180A and there were options for bigger and possibly additional alternator.

 

[rayrokni]

My recollection was that the standard alternator was ~180A and there were options for bigger and possibly additional alternator.

sorry, yes it’s 180amp alternator. which now means i can go with at least a 60 amp dc to dc charger and still be %50 off alternator max. i will look to see what options i have in the line of dc to dc chargers that you recommended

 

[rmaddy]

A 206 amp hour lithium battery is probably capable of accepting a 100 amp charge rate. If you install two of these batteries, then probably 200 amp charge rate (check the battery specs).

The SOK 12V 206Ah battery has a recommended charge current of 40A, max of 50A. Two in parallel can take 80A to 100A.

 

[rayrokni]

ok, after help from you guys and more research i have come up with this plan, let me know what you think for my case use:

renogy dc to dc 50amp mppt charger
renogy pure some inverter 3000w( to have room to grow)
starting with 1x 200ah 12v lithium phosphate ( idk which company to go with yet, doing research)
im going with 4awg from starter battery to charger to battery and inverter. with correct size inline fuses.
dc fuse box
an ac charger to charge plugged into shore line ( don’t know which to get yet. or if there is a ac/dc to dc charger.
at a later date, add solar panels.

let me know what you think.

thank you for your help and advice.

 

[rmaddy]

4AWG to the inverter is way too small. 3000W / 12V = 250A. You need 4/0AWG wire, not 4AWG.

 

[MisterSandals]

renogy dc to dc 50amp mppt charger

You probably already know this but it will require a signal to start charging from an IGN source. I think it can be controlled manually with a switch too but the danger is leaving it on and draining the source battery.

 

[rayrokni]

You probably already know this but it will require a signal to start charging from an IGN source. I think it can be controlled manually with a switch too but the danger is leaving it on and draining the source battery.

yes, thank you. i was also thinking of adding n on/off switch so i can turn it on after alternator has been running a few minutes. and to just isolate equipment. i’ll be adding switches to isolate individual equipment.

 

[rayrokni]

4AWG to the inverter is way too small. 3000W / 12V = 250A. You need 4/0AWG wire, not 4AWG.

right, thank you

 

[John Frum]

@rayrokni Renogy's reputation is pretty much in the toilet.
In addition to Renogy's lousy support that dc2dc converter you are suggesting has caused folks a lot of grief.