New DC to DC Charger From Renogy-20 amps or 40 amps-Flooded/AGM/GEL/Lithium

[continuecrushing]

trying to understand if anyone as the knowlege. if i have this 20A dcdc charging the battery, will my solar controller that is independantly attach the the same battery will also be charging at the same time?

so 20A from dcdc plus 10A from my solar for a 30A when the truck is running?

In therory, it could/will. Usually, they aren't outputting max power for very long, so it won't see that output much/very long. There is no issue with leaving both plugged in at the same time. Plus your solar isn't going to be providing full power (most likely) since that depends on sun/battery levels anyway.

 

[dreadlocks]

Usually its limited to its amp output regardless of its source.. havent found much info on the DC & Solar charger tho.. so YMMV..

however unless you have a Lithium, a single battery is unlikely to take much more than 20A for any reasonable time.

 

[RigidYota]

Annoyingly Renogy Canada don’t have these available yet, but US and Australia do.

The Australian site only ships to Australia and the US site ships to Canada, but charge $150USD for delivery... The only places that sell them also either drop ship from Renogy (and charge the same shipping) or don’t ship to Canada (Amazon).

In contact with their Canadian CS at the moment and apparently they may be available in a couple of weeks, but that was about a month ago. Waiting for a reply back for updates.

I am also up in Canada, chasing similar issues. Who is their Canadian CS?

 

[baltik]

Dumb install question, directions say: "Connect the negative cable directly to the negative terminal of the battery, and not to the chassis of a vehicle or boat."

I have a fairly complex run from starter battery to Dc/DC converter and was planning on running an 8AWG + wire only and grounding the converter on a clean chassis ground nearby. any reason the instructions are specifically against this?

 

[Amp34]

I am also up in Canada, chasing similar issues. Who is their Canadian CS?

I just used the email on their website “Onlinestoreca@renogy.com”, Flora was the one responding to me. Presume thir CS are based in Australia as they replied at 3AM.

 

[Jonnyo]

In therory, it could/will. Usually, they aren't outputting max power for very long, so it won't see that output much/very long. There is no issue with leaving both plugged in at the same time. Plus your solar isn't going to be providing full power (most likely) since that depends on sun/battery levels anyway.

excellent. i m also in canada, okanagan valley and from may to september...we get full solar power for 6-8h daily so i can get 60-80ah daily out of my 200w panel. never need that much as it goes into float mode usually. But as i camp in shade or in late fall, it would be nice to have one of those DC-DC.

another question for everyone. with a battery Bank of 340ah should i get the 20A vs 40A DCDC charger? is 40A too strong of a charge for the batteries? (2X 6volt rolls in series and paralle with a group 27 12v rolls)

 

[Jonnyo]

Annoyingly Renogy Canada don’t have these available yet, but US and Australia do.

The Australian site only ships to Australia and the US site ships to Canada, but charge $150USD for delivery... The only places that sell them also either drop ship from Renogy (and charge the same shipping) or don’t ship to Canada (Amazon).

In contact with their Canadian CS at the moment and apparently they may be available in a couple of weeks, but that was about a month ago. Waiting for a reply back for updates.

in the same boat..... right now, you can get those units for 10% off with coupon code ''welcome10'' and free shipping if you have a USA adress. so i m getting mine ship to oroville about 45min from where i live and i will go pick it up. that mean 113$ for the 20A or 180$ for the 40A including shipping!

 

[RigidYota]

in the same boat..... right now, you can get those units for 10% off with coupon code ''welcome10'' and free shipping if you have a USA adress. so i m getting mine ship to oroville about 45min from where i live and i will go pick it up. that mean 113$ for the 20A or 180$ for the 40A including shipping!

I'm doing similar, have a vacation in California later this summer and the spot im staying offered to accept and hold a package for me. Tempting....

 

[shade]

another question for everyone. with a battery Bank of 340ah should i get the 20A vs 40A DCDC charger? is 40A too strong of a charge for the batteries? (2X 6volt rolls in series and paralle with a group 27 12v rolls)

As long as your alternator can handle the load, the 40A model would make a lot more sense for a 340Ah battery bank.

I hope people are paying attention to the environmental specs on these units. The ad copy may claim it, but the manual (see page 17) doesn't agree with it being "Built tough for all conditions". I wouldn't put one in an engine bay, but sheltered in a camper or the bed of a truck should be ok.

 

[Amp34]

Forgot to mention in my earlier reply. They got back to me and said late August for the Canadian store now.

I’m now considering the same, I may get it shipped to a border warehouse and pick it up when I go and get my camper (next month hopefully). I’m a four hour drive from Sweetgrass so not as easy as 45 minutes unfortunately.

Out of interest how much heat do these things usually generate? I’ve got an ~2cu ft “box” this thing will be located in, along with a 100Ah lithium battery. Not sure if I’m going to need some ventilation to the rest of the camper.

 

[shade]

Out of interest how much heat do these things usually generate? I’ve got an ~2cu ft “box” this thing will be located in, along with a 100Ah lithium battery. Not sure if I’m going to need some ventilation to the rest of the camper.

Putting one of these inside a small, unventilated box isn't a good idea. It uses active cooling (fans) for a reason, and the manual warns against poor ventilation and high temperature operation.

 

[Amp34]

I understand that, but the definition of small is what I’m asking for. I can’t see many electrical/battery compartments being much bigger than the one I have, hence the question.

If needed I can set up a couple of 12v fans to exchange the air with the inside of the camper based on heat.

 

[shade]

I understand that, but the definition of small is what I’m asking for. I can’t see many electrical/battery compartments being much bigger than the one I have, hence the question.

If needed I can set up a couple of 12v fans to exchange the air with the inside of the camper based on heat.

I don't think there's a meaningful way to define that since it comes down to the ambient temperature inside the compartment while charging, and there are a lot of variables that'll determine that temp.

If you're pushing max amps for a long enough time, it's going to get hot inside, and at 40°C the charge rate will be automatically reduced. As long as you have a plan to increase the air exchange if needed, it may not be a problem. I'd at least stick a simple thermometer with a probe on the compartment so you'll know what's going on in there.

 

[luthj]

That unit will be around 80% efficient probably. So at 20A@12v, thats about 50 watts or so. Toss a 50W heating blanket into the enclosure, and time how long it takes to reach 120F. If thats longer than it takes to charge your batteries, your golden. If it heats up quickly, you need some ventilation.

 

[shade]

That unit will be around 80% efficient probably. So at 20A@12v, thats about 50 watts or so. Toss a 50W heating blanket into the enclosure, and time how long it takes to reach 120F. If thats longer than it takes to charge your batteries, your golden. If it heats up quickly, you need some ventilation.

That should help.

I was thinking more about environmental & use variables. There'd be a significant difference in the heat generated recovering after a deep discharge while in Death Valley in August compared to adding a minimal charge while in Leadville in February.