Use Inverter-charger to charge from alternator?

[Yuri]

I'm investigating dc-dc charging options.
I have 12V 460AH Epoch essentials battery bank.
It would be nice to have shore power charging as well.

My first plan was to get some power converter like Powermax PM3-100LK Converter to charge from shore power (I need at least 75A to be able to run 12V Air Conditioner from it) and Victron Orion XS that can provide 50A for $320.
But with power converter I may have issues with Epoch battery as charging voltage must be no more than 14V, and it looks like most of power converter profiles use over 14V charging. I could set it to fixed 13.8V. Also Orion XS is limited to 50A.

I'm thinking might be car 12v->inverter 120v->12V Victron Multiplus inverter/charger be a good option instead?
I can use my current 1500W inverter to convert alternator 12V to 120V for Mutiplus shore power input.
Limit Multiplus shore power to 1000W and use it to charge battery while driving, and connect Mutiplus to shore power when needed.
I have Victron BM-712 battery monitor with relay I can configure to switch 1500W inverter off if engine is not running.
I assume there will be some additional power loss on double car 12v->inverter 120v->Victron Multiplus 12V conversion.

Have anybody tried that and how bad that idea is?
I'm on budget and Orion XS is pretty expensive for what it is, maybe a used Multiplus might be a better way to go?

 

[MakeMePower]

charge voltage is 14.2, doubht you would have issue with any of them.
Update max is 14.6V. You can use any normal charger

12V 460Ah Heated & Bluetooth LiFePO4 Battery - Epoch Essentials

Get the 12V 460Ah heated & Bluetooth LiFePO4 battery from Epoch Essentials. Charge in sub-zero conditions, control with iOS and Android apps, and enjoy the benefits of smart battery management. 4,000+ cycles, 11-year warranty.

www.epochbatteries.com

 

[hardtop]

You could do that, I thought of it but decided to use a generator. Its way better and puts out 15A 120V AC and from that I can charge my 304ah pack while running all my gear in parallel. You'll need to drive a lot to recharge a 460ah pack from empty.

 

[Yuri]

charge voltage is 14.2, doubht you would have issue with any of them.
Update max is 14.6V. You can use any normal charger

12V 460Ah Heated & Bluetooth LiFePO4 Battery - Epoch Essentials

Get the 12V 460Ah heated & Bluetooth LiFePO4 battery from Epoch Essentials. Charge in sub-zero conditions, control with iOS and Android apps, and enjoy the benefits of smart battery management. 4,000+ cycles, 11-year warranty.

www.epochbatteries.com

I just installed that battery, so don't have much experience with it. Data in user manual and on their website seems incorrect, because support said to not use over 14V as it can trigger BMS full charge error/protection mode.

 

[MakeMePower]

I just installed that battery, so don't have much experience with it. Data in user manual and on their website seems incorrect, because support said to not use over 14V as it can trigger BMS full charge error/protection mode.

I would be testing that, there is no reason for it to be set that low. their cells aren't special. and their paperwork agrees with that comment

 

[HarryN]

I would look at Samlex or magnum for that application, as it has worked for this guy.

Electrical | Orton Travel Transit

www.ortontransit.info

At a fundamental level, your aux battery pack has to be capable of dealing with the required power in / power out rates - easily, or the application will fail. That is why a lot of people buy multiple smaller batteries instead of one large one.

 

[justinm001]

Going from 12V to 120V to 12V isn't ideal as you'll have quite a bit of losses and heat. The Orion XS is the perfect device for this and 50a which is quite a bit. How much amperage can you safely pull from your alternator? You could get 2 Orion 12/12-30's for about the same price and get 60a,

I'm surprised they don't have 70a orion's for 12/12. I have 24v alternator (270a) and run 2 24/12-70a and 4 24/48 8.5a (480w) to charge both my systems on the go.