recommendation for dc to dc charger

[New Comer]

I need recommendation for a dc to dc 12v charger, hopefully 30 amp. If not, I will consider 20 amp. Please recommend everything else I need to set up the system, except the batteries. I intend to use AGM batteries for now but LifePo4 Lithium batteries in the future. I am going to have a local car repair shop to install the system, so I have to have everything I need ready. They know nothing about the system. They can install it by the instruction (that is what they told me). They told me that they have installed quite a few systems in the past.

Please tell me where to get the charger and everything else if you can.

Thank you all in advance.

 

[sushidog]

What voltage DC will you be starting with?

Chip

 

[New Comer]

What voltage DC will you be starting with?

Chip

My car was built before 2006. I guess it has enough of voltage to charge an AGM battery with the DC/DC charger to regulate the voltage. However, I think it will be safer to use a DC/DC charger. I can also expand to solar in the future.

Thanks.

 

[XERTYX]

I dont know anything about dc to dc chargers. I know there are battery Isolators to charge a second battery from the vehicles alternator but if you're going to be using very much power at all it is my understanding that relying solely on alternator charging you'll have to be driving several hours per day. Simply idling the car wont do the trick.

If you're driving several hours to work and back each day that may be an option. I dont know how quickly AGM batteries will charge but I do know that flooded lead acid batteries take many many hours of constant charging to be full.

Just because your alternator can output X amount of amps let's use 60 amps as an example. Doesnt mean that all 60 go right into the battery. The bulk charge is fairly quick but then get all the way full takes time.

It was my understanding at the start that if the alternator put out 60 amps after 1 hour 60 Ah would be replaced. This is not the case. There are other members who know a lot more about the practical usage of alternator charging and I hope they can give you more real world knowledge on the subject than I can.

Another thing to consider is adding a solar panel right away. It doesnt have to be permanently mounted. Many people use portable panels and connect them when they park. Even the so called suitcase panels have came down in price quite considerably in recent years.

At any rate if you're going to be using the house battery for more than lighting and cell phone charging you may need to consider additional charging methods.

 

[sushidog]

Thanks for the info Newcomer. I thought you might want to tap power from a higher voltage bank, say 24 or 48v. Charging one 12v battery from another - I assume using your alternator, is impractical and unadvisable. Adding a second, high power alternator, like the guys with super big stereo equipment use would work, but it would be expensive and like Xertyx said, you'd have to drive a many hours daily - also not very practical except in unusual circumstances - say you had a job that required lots of driving, like a road salesman or an uber driver. You might be better served with a hybrid system, such as alternator plus solar, but I second Xertyx's recommendation for a cheap portable solar system.

Here's an example of a cheap, portable, solar beginner system that might serve your needs. 100 watts with controller for $150.
https://www.amazon.com/HQST-Polycry...ble-Controller/dp/B06XWL79L7?tag=ecotality-20

Chip

 

[XERTYX]

DOKIO 80 Watts 12 Volts Monocrystalline Foldable Solar Panel with Charge Controller https://www.amazon.com/dp/B0748GKHZ8

This one is $120 but only 80 watts but will be a little lighter in weight than the other one posted. Also this one is designed to be used with or without battery and I worry HQST controller may be like most solar controllers and if you disconnect the battery before the panels or connect the panels before the battery youd fry it. So this one to me seems just slightly safer in the event that you're sleepy and make a mistake in the order you connect everything.

Alternatively if you have the room to stow a panel inside there are $83 100 watt panels all over amazon. Rich solar I think and HQST maybe dokio as well. Then just buy a $20ish controller and you're coming out cheaper still. Then just like with those folding panels youd simply plug in the panel when needed and start charging.

There was a sterling I think battery to battery charger I saw reviewed on toutube but I belive their base model is around 600 bucks and still youd have to drive hours at a time. But from what the reviewers said they are the best on the market.