DC to DC charger with MPP Solar all in one unit

[bmklawt]

Hello,

New to the forums and to solar, looking for and easy to install solar setup, I would like to add solar to my camper and was wondering if I used a MPP Solar inverter, https://usamppsolar.com/product/pip-lv2424-msd/ if I could also add a DC to DC charger to the batteries so I can charge the batteries from the tow vehicle, is this something that is doable, will the DC to DC charger effect the MPP Solar inverter?
I was looking at these units:
Renogy 12V 20A DC to DC On-Board Battery Charger https://www.renogy.com/12v-20a-dc-to-dc-on-board-battery-charger/
Renogy DCC50S 12V 50A DC-DC On-Board Battery Charger with MPPT https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt/
Victron Orion-Tr Smart DC-DC Charger Isolated https://www.victronenergy.com/dc-dc-converters/orion-tr-smart#manuals

Your help is greatly appreciated,
Bruce

 

[Lt.Dan]

Well the MPP unit you listed is a 24v model, and the DC to DC Chargers you listed are 12v models. You cannot charge a 24v battery from a 12v charger.

 

[bmklawt]

Well right of the bat I can tell I don't know what I'm doing

 

[Lt.Dan]

Its ok, we all start somewhere. See if you can pick up @Will Prowse's Book, its got a ton of very basic knowledge to get you started. I bought it a long time ago and it has well paid for itself.

 

[bmklawt]

Is there a way to charge a 24 volt battery from the tow vehicle alternator?

 

[John Frum]

Is there a way to charge a 24 volt battery from the tow vehicle alternator?

Yes.
Both Victron and Sterling make 12->24 volt dc2dc chargers.

 

[jbird526]

@bmklawt If you don't need 2000w you could stick to 12v and use https://watts247.com/product/pip-1012lv-ms/. If your camper is already 24v then well, look up the 24v dc to dc converters.

As @smoothJoey will advise, and others, do an energy audit to decide if a 12 volt system and 1000 watts is enough for your demands. Also if you are powering a camper, check what the drop voltage is to your camper using https://www.bluesea.com/resources/1437. I'd even say size up one gauge for a long run if you can justify the diff in cost. Also look at Anderson connectors to plug into your tow vehicle from the camper.

 

[bmklawt]

I did do an audit and and came up with 1600 watts is the max I'd ever use at one time, I am redoing the camper as we'd like to do more camping, month at a time now that me wife is retired. My pie in the sky idea at first was to be able to run everything off solar, AC, microwave, coffee pot, hairdryer and others but the expense is not justified, I'll use my generator when needed. Then looked at Renogy system but a lot of people said the monitoring app wasn't very good so I am currently looking at an all in one system which is about a 1/3 the price of a Renogy system but would like to be able to charge the batteries as I tow and looking for an anwser if I can add a DC to DC charger and if that would work with the MPP Solar inverter, don't want to screw any thing up with batteries or inverter.

 

[jbird526]

Honestly would trust the Renogy as much as I trust the MPP, at least the MPP is much cheaper initially and if replacement needed a quick swap. Not knocking MPP but it isn't tier one equipment and that is fine. I have some Renogy MPPTs and they are fine for what they do. A cost vs risk analysis is completely reasonable. I would like a full Victron system myself but can't justify the cost.

I don't see why there would be any issue with the MPP and a DC too DC. Think of it this way, many us on these boards build systems with independent components each day and they don't speak to one another with no detrimental results. Yes there are smarter systems that communicate via VE Bus and CAN but those are out of OUR league at the moment.

I would recommend spending the money on either a Victron or Sterling DC to DC though. I would not like to trust anything cheaper with your tow vehicle electrical system. That is where money and piece of mind are worth the added cost. 25% more for a DC to DC is better than a new alternator. I just replaced the alternator on my 2000 Acura today and that was $170. Just old alternator, not related to anything here.