[rene12341]

Has anyone measured the actual output of the alternator voltage? I want to look at the possibility of using the alternator to provide a partial bulk charge to a lithium battery. Volts must stay below 14.5V.



Sent from my Pixel XL using Tapatalk

 

[Budsky]

Mine shows 14.7 at times on the built in voltmeter accessed through the OBDII port via the Torque app.

 

[rene12341]

Thanks for the info. I pulled a Duh! on that one. I also have the Torque app and it didn't occur to me to have a look.

 

[rene12341]

Well now I am more confused. I went out and checked using Torque and found there are 2 Volts listed, Control Module and OBD2. Highest on CM was 14.3V but highest on OBD2 is 14.9V.

Does anyone have any idea why they are so different? I wish Torque displayed battery voltage but that option is greyed out. I may need to put a recording meter on the battery and drive around.

Are the CCP terminal a valid way to check battery voltage? They are much easier to get to than the battery.

 

[joefromga]

Just measure where you are connecting the aux device. It doesn't matter elsewhere.

Put your meter on hold for highest reading and drive around or rev the engine. It will tell you exactly how much you're outputting.

 

[rene12341]

I intent is to connect at the CCP. Where is a good ground near the CCP or can I just use the chassis?

My intent is to use the available 180 amps available at the CCP as a backup charging method for my lithium batteries. The CCP connection will go through a BlueSea 2146 ML-ACR. This will always be in the manual disconnect mode unless for some reason (bad weather) the solar cannot keep the batteries charged. In that case I will open the ACR connection and use the engine to bulk charge the batteries to 80+ %.

Sound reasonable?

 

[BigMac77]

Theres a ground between the 2 seats on the floor..

 

[joefromga]

Sounds like a good idea.

 

[Budsky]

Well now I am more confused. I went out and checked using Torque and found there are 2 Volts listed, Control Module and OBD2. Highest on CM was 14.3V but highest on OBD2 is 14.9V.

Does anyone have any idea why they are so different? I wish Torque displayed battery voltage but that option is greyed out. I may need to put a recording meter on the battery and drive around.

Are the CCP terminal a valid way to check battery voltage? They are much easier to get to than the battery.

I figure the highest one is closest to actual alternator voltage- the CM one probably has some wiring losses.
BTW the voltage varies according to intake air temperature also, the PCM controls it- colder= higher voltage.

 

[RonR]

Just starting on my Transit but a couple of comments from charging lithium in a Sprinter.
Lithium batteries could easily draw 2 to 3 times the battery size in current. So a 100AH battery could safely use 200 to 300A. Clearly something that would not happen in a Transit or Sprinter. The sprinter alternator cables are only AWG 2 so as the current goes up there is more voltage loss in the wire. At high currents the voltage out of the alternator also goes down. The max I have seen, in a sprinter with a 220A alternator, was 80A. (I use 00 cable to connect to the transfer switch.)
I would expect the same from the Transit. It has a 180A alternator but would only deliver less than 100A due to voltage loss in the wire and the alternator voltage going down to protect itself.
But, when near full charge with the charge current going down the charge voltage goes up. I see 14.2V on a Sprinter. The Transit should be close since this is about the correct voltage for a standard battery. In my system (solar and alternator) I used a switch to disconnect the alternator once near full charge, to keep from overcharging the lithium. My Transit build will automate that function.
In my experience there seems to be very little gain in capacity by charging lithium (Voltronix) past 14V.
The 14.9V, mentioned earlier in this string, should / would never be applied to the battery unless there was some sort of a failure.
Ron

 

[sschefer]

With the not so smart charging system in the Transits, alternator voltage can be all over the map depending on what the PCM decides is needed to minimally maintain the battery. The whole concept of smart charging is driven by EPA fuel mileage requirements. The concept is that the less the alternator has to work, the less it's load will be on the engine. As it stands, the smart charging system can correctly charge a single calcium battery or matched dual AGM batteries. It can also handle a third battery in parallel but it must be matched to the other two. I think that in reality you could put as many batteries in parallel as you wish as long as they are all identical and the parallel connecting cables are correctly sized. I probably wouldn't try that without the alternator upgrade.

O.K. well not many of us boondockers are going to want to stack a bunch of group 24 combo (deep cycle/Start) batteries in our van's because at best they are a compromise and not a true deep cycle. They won't last long if we take them down below 40% repeatedly even though they claim they can go to 20%. And, since they are all in parallel the risk of not being able to start the vehicle due to a dead battery is ever present. Heck, it's ever present without any additions.

Instead, we're going to go with some form of long lasting battery and at that point you have to forget about using the vehicle to charge them. Or do you? Redarc and Sterling currently make Battery to Battery chargers that deal specifically with the smart charging problem. Rather than explain them here, go to http://www.sterling-power-usa.com/ and read through their user manuals to decide which unit fits your needs best.

I've had my share of problems with the Smart Charge system on my F-150 and my Transit. After multiple trips to the dealer I developed a phobia about having any of my house systems touching the vehicles system in any way. Apparently, I'm not alone. Sterling has a solution for fully isolated house systems too!

That's my best advice. Take it or leave, I'll still let you borrow my generator to start your van when (not if) you need it.

 

[GROOVY2]

Have been researching charging a set of Lifepo4 cells for van-

seems like the Radio Control guys have what I need to charge the Lifepo4 correctly-
Calb cells-

Dont know if charging these batteries without good control of what is going on is a lasting answer-

I was thinking of using one of these charger hooked to Sterling Battery to battery charger-
these chargers have adjustable current and voltage CC/CV - Balancing 8 cell -

Have been using Li ion for a long time and have had only 1 bad battery -
I use a good charger and really have zero problems from all my batteries -

have watch videos of both of these chargers in use -
seem to have claimed output and work well -

This company has been making quality RC E power gear for years-
http://www.graupnerusa.com/Polaron-EX-1400W-8S-3-Color-and-Touch-TFT-Red.html

or

http://www.icharger.co.nz/Products/4010-Duo.aspx

 

[GROOVY2]

this is a good read on Lifepo4
http://www.pbase.com/mainecruising/lifepo4_on_boats

 

[orton]

Instead, we're going to go with some form of long lasting battery and at that point you have to forget about using the vehicle to charge them. Or do you? Redarc and Sterling currently make Battery to Battery chargers that deal specifically with the smart charging problem. Rather than explain them here, go to http://www.sterling-power-usa.com/ and read through their user manuals to decide which unit fits your needs best.

I have had very good results from using the vehicle 12 volt system to provide 120 volt AC while you drive by installing a pure sine inverter powered by the vehicle.

Advantages:

1. No direct connection of the house battery to the vehicle battery. System is isolated from the vehicle system.
2. The size of the vehicle powered inverter limits the load on the alternator.
3. Use shore power charger to obtain the correct 3 stage charge profile for your house battery.
4. No large cables connecting house to vehicle battery.
5. No connecting relay.
6. House 12 volt system can be free standing and not grounded to the chassis.
5. The power is available for other uses. I heat shower water electrically and have a 750 watt baseboard heater in the rear. Will probably also power an air compressor.

Disadvantages:

1. You can not use the house battery to start the vehicle.
2. The size of the vehicle powered inverter limits the load on the alternator.
3. Slightly higher cost.
4. Less efficient because you are converting 12 volt power to 120 volt power and then back to 12 volt power. This is not important because the only extra cost is a minor change in MPG. Probably not measureable.

In my case my 300 watt solar panel with a MPPT controller normally provides all the power required to maintain 100% SOC. The vehicle powered inverter is a backup for bad weather so seldom used. It does provide an inexpensive method of heating shower water that eliminates hot & cold water mixing as well as the shower plumbing. Water heating cost savings more than offsets the cost of the inverter.

 

[DrJean]

.

remind me? Do you have the heavy duty alternator on your van?

 

[sschefer]

remind me? Do you have the heavy duty alternator on your van?

No, I don't.

 

[Michael Ophus]

this is a good read on Lifepo4
http://www.pbase.com/mainecruising/lifepo4_on_boats

now i remember why i chose Not to use lithium in the transit! i remember reading this before, maybe another time when you shared it with us. If you still choose to go this route? the sterling B2Bs have lithium charge profiles and Voltage Sensing, plus with the optional remote you can set the amperage draw to any value for your transit alternator. (you can limit the amps used.)

 

[sschefer]

now i remember why i chose Not to use lithium in the transit! i remember reading this before, maybe another time when you shared it with us. If you still choose to go this route? the sterling B2Bs have lithium charge profiles and Voltage Sensing, plus with the optional remote you can set the amperage draw to any value for your transit alternator. (you can limit the amps used.)

I looked at Lithium options also but they just didn't seem cost effective to me. I seriously believe that battery technology is in for a big change soon. I have no idea what that might be but I know it's coming and don't want to get stuck with a bunch of expensive equipment that won't work with whatever the next generation brings.

I'll go solar when a system that fits on my roof can charge my 500ah worth of batteries as fast as my generator can. Perhaps the next generation of batteries will allow that to happen but until then I'm holding my credit card close to my heart.

 

[GROOVY2]

the Main drawback to using any of the Li ion type batteries is
the lack of Proper chargers for Li ion type batteries bigger
than cell phone or RC type battery packs --

Vast majority of Larger chargers that claim to charge Li ion
are just RE Branded Smart Lead chargers that will Trickle charge and Kill Li ion batteries
over time - Be careful -

Li ion (all Types ) need CC/CV charger -
Charger need so shut off Charging to battery Completely once set voltage is reached -
Zero trickle or Float -

100 amp hours of good quality Lifepo4 cell cost $550 - weighs 32 pounds - small -
voltage constant - rapid 3 C charge /discharge - -

If proper charger is used a good quality Li ion battery will likely last longer than the Van -

Lead will last a long time too - Tons of chargers and gear and knowledge -
lead costs maybe half as much to build - twice as much battery and space is needed tho -
3X weight -

I would like to use Lifepo4 but proper chargers for
what i need in a van are very limited -

 

[RonR]

Groovy2 I think you are being a little too pessimistic.

In a previous build I used 480AH of Lithium Iron (the only type being used in RVs and much more forgiving compared to what is used in a cell phone or laptop). My standard MorningStar MPPT solar controller had a standard profile that was perfect and I used a cheap BMS circuit to disconnect the battery from the alternator when the correct voltage was reached. I used 14V.

Most of the time solar was fine to keep things charged. When I used a lot of microwave or the electric water heater the alternator would pump out about 80A to get to full charge pretty quickly. In that build (a sprinter) the factory wire to the alternator was AWG2 and there was enough voltage drop in the wire that the max current is limited to about 80A despite using AWG00 wire from the battery to the transfer relay. I suspect the same would be true of the Transit. I did not order the heavy duty alternator.

Ron