diy solar

diy solar

High AMP DC-DC charger

HRTKD said:
Freep, what type of vehicle do you have? Is this a motorhome or a truck/trailer?
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2014 Lance 992 on a 2014 Ram 3500 dually with cummins diesel. It's a slide in truck camper. It looks very much like this but with two 150 watt solar panels and a single plastic shell for the "nosecone".
 
Freep said:
2014 Lance 992 on a 2014 Ram 3500 dually with cummins diesel. It's a slide in truck camper. It looks very much like this but with two 150 watt solar panels and a single plastic shell for the "nosecone".
Click to expand...

You might be interested in this "experiment" in using only the alternator to charge the slide-in camper batteries: https://www.mortonsonthemove.com/toms-tech-blog/truck-camper-lithium-alternator-charging

Are you using the 7 pin to power your DC-DC charger? Sorry for the dumb question, but it isn't clear if you have run a dedicated line from the truck battery to the DC-DC charger.
 
Actually, I did a mod to the truck and camper to have two plugs, one for power and one for lights. The 7 pin proprietary Lance plug and harness were needed because of the 8 gauge wire, but the plug kept slipping while driving. That was just terrifying.

But to answer your question, yes the power plug connects the Victron Orion-tr directly to the truck. The Orion wasn't working properly but I just got a beta firmware update which has fixed the problem and it charges the battery well. I just wish their app provided more information. When driving we're a little too far from the battery to connect to the BMS.
 
Freep said:
Actually, I did a mod to the truck and camper to have two plugs, one for power and one for lights. The 7 pin proprietary Lance plug and harness were needed because of the 8 gauge wire, but the plug kept slipping while driving. That was just terrifying.

But to answer your question, yes the power plug connects the Victron Orion-tr directly to the truck. The Orion wasn't working properly but I just got a beta firmware update which has fixed the problem and it charges the battery well. I just wish their app provided more information. When driving we're a little too far from the battery to connect to the BMS.
Click to expand...

The reason I asked how you were getting power to the camper was that the Ford Super Duty trucks (I realize you're in a RAM) aren't getting much current from the OEM 7 pin. The amount of current is maybe enough to maintain the batteries SOC, but unlikely to bring the batteries to 100%. The workaround there is to run a dedicated wire from the truck battery to the DC-DC charger. That will give you more current to work with.
 
HRTKD said:
The reason I asked how you were getting power to the camper was that the Ford Super Duty trucks (I realize you're in a RAM) aren't getting much current from the OEM 7 pin. The amount of current is maybe enough to maintain the batteries SOC, but unlikely to bring the batteries to 100%. The workaround there is to run a dedicated wire from the truck battery to the DC-DC charger. That will give you more current to work with.
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Yeah none of those OEM plugs are wired to do much more than control lights on a trailer and power brakes.

The biggest problem I have now is getting enough information about DC-DC charger output and alternator performance to make a good decision on what to do next. I could run another set of wires and add another Orion-TR. I could also upgrade my alternator or add another one.
 
I have seen ~30 amps coming from the Orion. However, I have to look at the MPPT controller and the battery BMS app to figure that out. I don't get that information from the Orion itself, which is extremely annoying. All the app for the Orion says is whether it's Bulk or Absorption and what the voltage in and out is.

So for Bulk, I'm assuming it's maxing at 30.
 
Freep said:
I've got an Orion TR 30 AMP charger but I'm starting to realize that I should have gotten myself a bigger charger since my alternator is a 180 AMP alternator.

Any recommendations? Ultimately, I'd like to get rid of the generator in my camper, which only gets occasional use and the most it will ever push is 45 AMPs through the PD4045 mighty mini.
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Freep, what did you end up going with for a DC-DC charger?
 
Ive had the Redarc 50amp unit for about 18 months in a honda odyssey. Solid unit, dc clamp meter shows about 45 amps going to the accessory batteries at idle, 4amps to the starting battery, plenty left from the alternator for the rest of the van. I did replace the alternator last month, though since the one I took out was a replacement I dont think the failure was unusual. Both Denso factory rebuilds, thats the only rebuilt Id use for an OEM Denso. They use japanese parts in a usa facility to repair units they built in the first place.
The redarc product is very compact, completely potted inside, made in australia. Imagine Jocko, Crocodile Dundee and Steve Irwin assembling your product after a fosters lager lunch hour. Im good with that.
 
I too want to eliminate the dependence on a generator. My battery bank is 1280 Ah. Obviously the problem is charging larger battery banks with solar. I've decided to go with CTEK Smartpass 120S coupled with their D250SE and utilize the vehicle alternator to assist in charging. With both CTEK devices, I will be able to safely achieve 140 Amps of coach charging. The D250SE also includes solar support as it has an MPPT controller built into it However, it only supports up to 300 Watts of solar. Since my solar array is 800 Watts I wont be using that part of their equipment. Instead, I will stick with a Victron MPPT controller; they did confirm this configuration is acceptable.

Curious if anyone has experience with the CTEK equipment or has suggestions as to why one would not use this configuration.
 
inetblue said:
I too want to eliminate the dependence on a generator. My battery bank is 1280 Ah. Obviously the problem is charging larger battery banks with solar. I've decided to go with CTEK Smartpass 120S coupled with their D250SE and utilize the vehicle alternator to assist in charging. With both CTEK devices, I will be able to safely achieve 140 Amps of coach charging. The D250SE also includes solar support as it has an MPPT controller built into it However, it only supports up to 300 Watts of solar. Since my solar array is 800 Watts I wont be using that part of their equipment. Instead, I will stick with a Victron MPPT controller; they did confirm this configuration is acceptable.

Curious if anyone has experience with the CTEK equipment or has suggestions as to why one would not use this configuration.
Click to expand...

I have two CTEK smart chargers (120v) that have done well. That's my exposure to CTEK.

140 amps from a motorhome alternator? That seems like a lot. How much is your alternator rated for?
 
HRTKD said:
I have two CTEK smart chargers (120v) that have done well. That's my exposure to CTEK.

140 amps from a motorhome alternator? That seems like a lot. How much is your alternator rated for?
Click to expand...
Thank you for your reply and input...

My alternator is 280 amps, but I plan on installing a 2nd alternator dedicated to charging the coach battery bank. I actually haven't received my RV yet. Its being built but the Generator option was $4K. I figure using these funds to build a better mousetrap. My RV is on a Sprinter chassis and has a factory location for a 2nd alternator.

Since you have CTEK, do you have both the 120 Smartpass and the D250SE? Its my understanding the D250SE only provides 20 amps but when coupled with the 120 Smartpass it can output 140 amps (20 plus 120). Though some of this current is being used for other consumers, the literature says it will output that much current. I'm hoping to verify. I'm assuming if they have overstated their system the ratings from others would be negative. It seems DTEK has a stellar reputation.
 
Is my math correct?:

Generator outputs 30 Amps so 30 x 120 = 3,600 Watts (if one were using a generator)
Alternator output 140 Amps so 140 x 12 = 1,680 Watts

1280 Ah bank: 1,280x12= 15,360 Watts (storing capacity)

Total time to charge bank if totally depleted: 15,360W/1,680W = 9 hours
 
A point often missed:

What is the duty cycle of an automotive alternator at elevated temperatures found under the hood?

Clue: its not 100%
 
It's my understanding that an alternator will perform OK when output is 50% of its capacity. If it's a 280 Amp alternator then 140 Amps is acceptable ie it won't burn it out. Is my understanding correct?
 
I understand at idle the alternater output would be less but traveling during the day would be the plan so I wouldn't be idling the Sprinter Chasis which I've heard is not good for diesel engines.
 
Cannot speak for the Sprinter in particular but its not true that diesels don't like to idle, Ive mostly had Cummins and International Harvester 6.9 &7.5 L. They loved idling....same for the big trucks...pete’s etc.
 
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