another DIY roadtrek lithium - newb needs help

[bumpersignal]

Originally Posted by larrylwill

I do not have any AGM batteries connected.
SO with no AGM on the alternator the alternator wont start unless I connect a 12v source to it. I can manually short it to my lipo4 to get it going but I don't want to have to remember to push a button every time I start to drive.

Forgive me because I'm new to all this but I thought DC2DC typically is :

alternator => battery 1 (lead acid usually) => dc2dc charger => battery 2 (in your case a lithium?)

HOWEVER, I think you're doing:

alternator => lithium

Is my understanding correct?

[larrylwill]

I am using the DC2DC because the alternator puts out too much current for my BMS. The DC2DC is 60 Amps will work, This info I got from others in this group.
I have a 2nd alternator without Balmar and now I do not have any batteries connected to it except the Lipo4. So to start the alternator one needs 12v temporally on the output to exceit the alternator to work then it goes to the DC2DC which cuts down the current from 280amps to 60 amps for my Lipo4 battery and BMS.

[bumpersignal]

Originally Posted by larrylwill

I have a 2nd alternator without Balmar and now I do not have any batteries connected to it except the Lipo4.

Right, and again, I'm sorry if I'm being dense but it sounds like you are no longer doing DC2DC since you're doing 2nd alternator straight to the lipo4?

[larrylwill]

Not correct. The alternator goes to the DC2DC but the alternator will not put out any voltage or current unless it sees 12v. Which can be a battery or temporary 12v source, once it starts outputting it will continue if you remove the 12v that started the alternator.

My mistake its not connected to the lipo4 except through the dc2dc.

[bumpersignal]

Originally Posted by larrylwill

Not correct. The alternator goes to the DC2DC but the alternator will not put out any voltage or current unless it sees 12v. Which can be a battery or temporary 12v source, once it starts outputting it will continue if you remove the 12v that started the alternator.

My mistake its not connected to the lipo4 except through the dc2dc.

Ok, so it's :

alternator => dc2dc_charger => lifepo4.

That's interesting! I hadn't thought of that. Although I wonder for the cost of the dc2dc_charger it would make sense to skip it and instead modify the alternator for external regulation?

alternator_with_balmar => lifepo4.

Assuming alternator_with_balmar won't have the "excite" issue that your dc2dc implementation faces?

[larrylwill]

Your are correct, If you have the balmar, In order for me to get one I would have to send in my alternator and pay Nations to install one at a cost > than $400. The 60 amp dc2dc cost < $150 But that was before I knew I would need to excite the alternator which all the people that insisted I buy the Dc2dc to fix the problem told me. Because they didnt have a 2nd alternator without balmar.

[bumpersignal]

So it sounds like Balmar solution doesn’t have the excite issue. And also being a simpler cleaner solution to power your lithium with more on tap in the future if you need it. Makes the balmar path well worth the ~$300 cost?

[larrylwill]

Maybe, depends if you need to charge at more than 60 Amps. Another solution I found is to add a 2nd BMS in parallel with the one I have about $100. Will Prouse tested 2 BMS in parallel and did not have any problems. However I already bought the dc2dc.

[bumpersignal]

Originally Posted by larrylwill

Maybe, depends if you need to charge at more than 60 Amps. Another solution I found is to add a 2nd BMS in parallel with the one I have about $100. Will Prouse tested 2 BMS in parallel and did not have any problems. However I already bought the dc2dc.

I can relate because when I started my research someone with a similar vehicle as mine suggested the same even though they also had a dedicated 2nd alternator. I needed >150amp charging so got TWO sterling dc2dc thinking that would be it. I started to realize it wasn’t the right path for me and will eat the cost and sell the sterling chargers on eBay and chalk it up as part of the learning curve.

[larrylwill]

Yes lots of different setups and bad information. One size doesn't fit all. I would order another BMS but Amazon doesn't have them anymore. I would have to order from China and wait another 2-4 months.

[bumpersignal]

I contacted a marine repair shop near me (at the advice of balmar tech support) and they quoted me $130 to convert the nations alternator to be externally regulated so that it will be able to use with the balmar. Perhaps you can find a similar shop near you. However thr balmar is still north of $300

[larrylwill]

Nations will add a Balmar for around $400 and it will be self excited. I have a couple of ideas how to excite it. I called Nations again and asked if I could put a diode from the starter battery to the alternator. The tech was busy and he was supposed to call me back. He never did. I doubt they know. Although i would put 12v on the alternator all the time, I have to check if there is any current drain. Another way is a short between the starter switch to the selonide if the 12v to the alternator connection stays at 12v long enough.

[bumpersignal]

Originally Posted by larrylwill

Nations will add a Balmar for around $400 and it will be self excited. I have a couple of ideas how to excite it. I called Nations again and asked if I could put a diode from the starter battery to the alternator. The tech was busy and he was supposed to call me back. He never did. I doubt they know. Although i would put 12v on the alternator all the time, I have to check if there is any current drain. Another way is a short between the starter switch to the selonide if the 12v to the alternator connection stays at 12v long enough.

Hmm if that’s true that’s a deal because balmar itself is $400 from their store. You better double check to be certain.m because they quoted me yesterday $400 + $100 shipping just for the servicing of the alternator to allow it to be externally regulated and connect the balmar harness.

[larrylwill]

Well they told me most people send in there alternator and they will add the balmar. I said I guess it will be around $99 and they said yes. I didn't pursue further. I'm not going that way. Ill buy a 2nd BMS first.

[booster]

Converting an alternator from internal to external regulation so you can use a Balmar is not difficult at all. All you do is remove a small cover that is over the regulator, take out the regulator and solder two wires to the points that the regulator was connected. Those two wire go to the field wires from the Balmar. It took me about 10 minutes and it was the first one I have ever done. I am sure there are lots of instructions of how to do it online as lots of folks do their own. No need to ship a heavy alternator two ways and pay to do it.


There have been some confusing things said on this discussion that I think could get misunderstood.


When you put on a Balmar it is true that the Balmar is what turns on (excites if you prefer) the alternator, but the Balmar will not do that unless it sees a battery in the system so is really no different than if the regulator is inside the alternator. The Balmar does not self excite the alternator in any way it excites it only if there is a battery present so it is the battery that controls the excitation in all cases. There has to be a battery connected to the output of the alternator to be able to get it to turn on. There are very, very good reasons for this as you will destroy things if you just power the field directly without the battery on the alternator output and some kind of regulator referencing the battery voltage. Don't read any of the posts as saying you can start the regulator without a battery connected either directly to the alternator or through a B to B or Balmar control.

[bumpersignal]

Yes but with the balmar path he would be connecting the lifepo4 battery direct to the alternator.

The crux of his issue is his current path he’s connecting the alternator directly to a dc2dc charger and then A lifepo4 behind the charger.

Maybe if he installs a lead acid battery before the dc2dc charger ? Would that be a simple way to alleviate the excite issue?

[larrylwill]

That's contrary from what Nations alternator told me. Please show us where you get that info from. I'm tired of believing and doing what other people say without proof or references. There are thousands of statements on the net that are wrong. Not saying you are but I want some proof. No offence.

[larrylwill]

Originally Posted by bumpersignal

Yes but with the balmar path he would be connecting the lifepo4 battery direct to the alternator.

The crux of his issue is his current path he’s connecting the alternator directly to a dc2dc charger and then A lifepo4 behind the charger.

Maybe if he installs a lead acid battery before the dc2dc charger ? Would that be a simple way to alleviate the excite issue?

That's one good solution and that's what I was going to do but the 2nd AGM battery less than 3 years old and sitting with a trickle charger also shorted. So I would have to buy another one. Maybe a small one would do.

bumpersignal: I did not intend to hijack your thread.

[bumpersignal]

Originally Posted by larrylwill

That's one good solution and that's what I was going to do but the 2nd AGM battery less than 3 years old and sitting with a trickle charger also shorted. So I would have to buy another one. Maybe a small one would do.

bumpersignal: I did not intend to hijack your thread.

No problem at all I think it’s been very helpful

[booster]

Originally Posted by larrylwill

That's contrary from what Nations alternator told me. Please show us where you get that info from. I'm tired of believing and doing what other people say without proof or references. There are thousands of statements on the net that are wrong. Not saying you are but I want some proof. No offence.

Here is one utube on the general principal.

https://www.youtube.com/watch?v=BaqNpEjWKOM

What he is doing is more complex because he is trying to adapt a different vehicle regulator to the alternator.


I dug out my now nearly 10 years old information from when I did ours. At the time Nations also gave instructions for DIY as I bought the second alternator from him and a mounting kit. The only question was which wire to which brush. I am not using a Balmar but the Ample Power I am using looks to wire similarly. The wiring for the regulator show one wire from the regulator to the field, which would connect to one of the brushes contacting the armature. The question was what was the return path for the field current and it appears with internal regulator it went from the other brush to the internal regulator and then to ground so that would indicate that brush would be grounded. IIRC the two wires I soldered on where to the brush lead wires and those connect to the external regulator field and ground connections. They don't want you to go through chassis ground back to the regulator as you might have voltage loss. The only question was which brush was witch and he addresses that in the video. The regulator may also have the connections marked on it. I think you can just put an ohmmeter on the brush wire and see what pin on the regulator it connects to.


I wish I had taken a pic of ours to show which was which brush, but didn't think of it at the time because I would know by looking if I ever had to take this on out and wire in new alternator.


If someone has an alternator with remote wiring not installed yet they could take a look easily. I don't think I can see in to mine without removing one of the alternators.



One thing that Nations may have been referring to is that I think on all of their alternators the brushes move in when you take off the cover and have to be held back to put when you put it back on. That might be the more complicated part he spoke of. It is easy to do with a piece of string on most motors and alternators and some have pin hols to to put a piece of wire in to hold them. That is probably why the warning if you are not familiar with that kind of stuff