How Much Juice Is Your Alternator Getting To The Camper Batteries?

[So Cal Adventurer]

Hey All

Question for the masses that have their FWC's wired to charge from the alternator while driving..

Obviously the #s will vary vehicle to vehicle, but has anyone actually measured how many amps their alternator is putting out to the FWC batteries while they're driving?

Example, using the Victron battery monitor app that shows real time #s, etc..

I'm working on something ill post up about when im done, but curious others opinions.

Thanks

 

[cwdtmmrs]

I don't have numbers nor do I have any way to get numbers, but I can say that my only charging has been from my alternator and I have never had a dead camper battery. I have a 120 amp alternator wired with 4 ga in addition to the 10 ga wires feeding a 12 year old Optima yellow top battery. I do have a 3 way fridge and usually drive every day.

 

[ntsqd]

Similarly I don't have numbers either. No way to pull that data from our battery monitor system as it was not a data logging unit. Our old camper was wired and breakered to allow 80 amps with less than 3% voltage drop. We usually move every day to every other day and with only 100W on the roof we never had low batteries once we got undamaged batteries in the camper. The camper's original batteries must have been abused and took me a while to realize that I had a battery problem rather than a charging problem.

 

[rando]

I have looked at these numbers from my battery monitor.

2016 Tacoma, 6AWG from engine bay to camper plug, stock wiring inside camper, 150Ah LiFePO4 battery.

I got around 7-8A for the first few minutes after start up, dropping to 5-6A after that.

I recently modified my wiring to allow my MPPT 100/20 to also act as a B2B charger, and I now get constant (programmable) 20A charge:
http://www.wanderthewest.com/forum/topic/18838-mppt-dc-dc-cheap-b2b/

I primarily rely on solar, so the B2B was more out of interest to see if it would work than necessity.

 

[So Cal Adventurer]

I have looked at these numbers from my battery monitor.

2016 Tacoma, 6AWG from engine bay to camper plug, stock wiring inside camper, 150Ah LiFePO4 battery.

I got around 7-8A for the first few minutes after start up, dropping to 5-6A after that.

I recently modified my wiring to allow my MPPT 100/20 to also act as a B2B charger, and I now get constant (programmable) 20A charge:
http://www.wanderthewest.com/forum/topic/18838-mppt-dc-dc-cheap-b2b/

I primarily rely on solar, so the B2B was more out of interest to see if it would work than necessity.

That’s pretty slick sir

 

[alano]

I have a current sensor in the battery box reading the alternator feed. It's wired to a readout looking through the front window of the camper into the back window of the truck. Alas, the rear-view mirror's polarizing won't let me read it while driving and I have to turn around, so I only look at it when stopped though the wife checks it if we have concerns.

I was getting about 5 amps through the stock 10 AWG wiring most of the time. Had troubles and I think my separator went wrong so I added 4 AWG wire on a shorter path and hooked in a 40 amp DC to DC charger. On the first test run with the batteries brought down a bit (lost SOC info when wiring things up) we measured 24 amps at freeway speeds. Since most trips we drive most days, this should keep things topped off nicely when the 200W of solar on the roof can't keep up due to clouds, shadows or smoke.

Alan

 

[craig333]

I suppose I should check. I haven't needed to since the solar does all the work, so far. Also 6ga wire so I have no reason to think it won't work but I'd sure hate to find out I fubar'd something. Easy enough to check after I draw the batteries down a bit.

 

[So Cal Adventurer]

I’m asking because for over a year I never had an issue, living in SoCal I’m spoiled and my 275 watts of solar always keeps things tip top.

But after a trip north and a week of full clouds and rain, I couldn’t keep the batteries topped off.

I ran some tests and did some things but curious what others are getting and their setups before I finalize my “fix”

Thanks

 

[Oilbrnr]

I just recently finished hooking up my Hawk a couple of weeks ago. Ran 4 AWG (more from the fact I had it laying around) from the starter battery back to a couple of single post lugs that I mounted under the bed directly below where the Attwood trolling motor plug comes through the bed. The Attwood piece itself is not overly inspiring, but I went with it for now.

The rest of the wiring is stock with a Blue Sea 7611.

So far the highest I've seen on the Victron is 24 amps when the SOC was ~70%.

Speaking of Victron, their app is a hot mess. No single pain of glass for their products is kinda wack. And no clock. Every time I go in and out of my parking garage at work, starts a new day on their MPPT history. But I digress.

 

[So Cal Adventurer]

Speaking of Victron, their app is a hot mess. No single pain of glass for their products is kinda wack. And no clock. Every time I go in and out of my parking garage at work, starts a new day on their MPPT history. But I digress.

That’s bizarre and sounds like a glitch. Mines worked perfect for about 1.5 years and nothing like that with the app.

 

[BFH4N]

I've seen the CTEK charger in my Fleet/Tacoma pumping about 50 Amps at 14.4 Volts into the camper batteries from the truck at 13.6 Volts, for a little while after starting the engine. It soon settles to a steady 20 Amps until the battery nears 100%. I have no way to tell what part of that might be from solar. The truck-to-camper wiring is 4 AWG, but I doubt it would really need to be quite that big.

- Bernard

 

[trikebubble]

I’m asking because for over a year I never had an issue, living in SoCal I’m spoiled and my 275 watts of solar always keeps things tip top.

But after a trip north and a week of full clouds and rain, I couldn’t keep the batteries topped off.

I ran some tests and did some things but curious what others are getting and their setups before I finalize my “fix”

Thanks

Alas, long live the propane fridge for us up here in BC. I do have the dual batteries and standard 160 watt solar panel, which do'nt seem to drain much as they don't have to worry about a 12V fridge at all. I also have 150 watts if portable solar panels I could use (have not yet, but will be in 2 weeks when I try to use my portable pellet grill with the camper for the first time and want to max out my electrical input). When I was ordering my Hawk, I was set on the 12V fridge, until our Canadian dealer suggested that given where we live, and where we will be camping/adventuring the majority of the time to really consider the propane fridge. I'm honestly really glad I did. It sips propane, and keeps things ice cold all the time.

 

[So Cal Adventurer]

Alas, long live the propane fridge for us up here in BC. I do have the dual batteries and standard 160 watt solar panel, which do'nt seem to drain much as they don't have to worry about a 12V fridge at all. I also have 150 watts if portable solar panels I could use (have not yet, but will be in 2 weeks when I try to use my portable pellet grill with the camper for the first time and want to max out my electrical input). When I was ordering my Hawk, I was set on the 12V fridge, until our Canadian dealer suggested that given where we live, and where we will be camping/adventuring the majority of the time to really consider the propane fridge. I'm honestly really glad I did. It sips propane, and keeps things ice cold all the time.

I know you love your propane fridge, you’ve told me many many times...

I’ve heard 10x many people dislike than like then though, soooo

But what does that have to do with this post? Hehehe

 

[ClimberRob]

6.6L Duramax, 4 AWG copper wire to Blue Sea SiACR to AGMs, I was getting between 14 and 83 amps.

I have since changed my setup to a single LiFePo battery and a sterling marine charger, and get a consistent 28 amps.

 

[trikebubble]

I know you love your propane fridge, you’ve told me many many times...

I’ve heard 10x many people dislike than like then though, soooo

But what does that have to do with this post? Hehehe

I don't know who this 10X person is, but he obviously lives in a sunny desert. And do t worry, I'll keep mentioning things that don't really have anything to do with your post for awhile...... or at least until you start geotagging again. [emoji6][emoji106]

 

[So Cal Adventurer]

I don't know who this 10X person is, but he obviously lives in a sunny desert. And do t worry, I'll keep mentioning things that don't really have anything to do with your post for awhile...... or at least until you start geotagging again. [emoji6][emoji106]

I’m going to Geotag your Skottle

 

[Vic Harder]

last month. 100 AH Li battery, Duramax 6.6 connected via Blue Sea ML-ACR

 

[So Cal Adventurer]

last month. 100 AH Li battery, Duramax 6.6 connected via Blue Sea ML-ACR

Nice!!

What is your wiring from alternator to batteries?

 

[Vic Harder]

2 gauge

 

[PaulT]

Piker! You can’t be getting more than 60-80 amps from your alternator with those small cables.
Shoulda gone with 2/0 cable..

Paul