Alternator battery charge rate - Isata 5

[vlamgat]

I know there have been several threads discussing the Generator charge rate and I believe this has been solved with a software upgrade to the Firefly interface. However, I do not recall nor have found threads discussing the charge rate from the dual alternator setup on these trucks. I had cause on a recent trip to monitor this and discovered that despite being able to get 100% charge rates at only an 80% discharged battery set from the Generator, the Alternators could only provide a 30% (and mostly no more than a 10%) charge rate.

So the question is do we have to change the charge parameters to get the LiPo battery (Explorer model) to accept a charge rate of more than 30%? Has anyone seen anything different?

[Phreak480]

What charge rate are you seeing from the alternators, actual amps? I'd check it against the output curve that Ram publishes for the dual alternator setup. They surely don't make 440 amps all the time, and the chassis sucks up some current with all it's electronics.

[TitanMike]

Originally Posted by vlamgat

So the question is do we have to change the charge parameters to get the LiPo battery (Explorer model) to accept a charge rate of more than 30%? Has anyone seen anything different?

Since a 30% charge rate is normal for Lead/Acid batteries I would guess that you are on the right track that parameters need to be changed. Does your instruction manual provide any guidance on setting up for LiFePo4 batteries?

[bclemens]

Let's not forget that the chassis still has lead acid batteries. In the 20 years I have been doing this, I have never had an issue with the chassis not properly taking care of the batteries and being fully charged on arrival.

[vlamgat]

Originally Posted by bclemens

Let's not forget that the chassis still has lead acid batteries. In the 20 years I have been doing this, I have never had an issue with the chassis not properly taking care of the batteries and being fully charged on arrival.

Excellent point! Of course I am talking LiPo in my case and the analysis was done before first light - 4 AM. Had spent the night at a Rest Stop on an Interstate with Inverter on, Sat antenna off but the other antennas on plus accent lights and other residuals. Victron reported 62%. Started up the truck and saw 30% Charge. So 30% of what? Battery capacity in Ah; Alternator output; Maximum accepted by the Magnum? Does the Chassis actually direct its charge directly through the Isolator module and the Firefly just reports what it sees? In which case what is it referencing/reporting?

[bclemens]

Understand you are talking lithium, but the alternator is really there just to charge the chassis batteries and its profile is set for that. We just happen to use some of that extra power as an aux source for the batteries, it will likely not be an ideal charge (but often more than needed). The charge line is back fed from the line that goes to the batteries from the Li-BIM. The Li-Bim is handling the connection only, the alternator would determine the charge so it should treat it like a lead acid battery.

Logic would lead me to believe that the Firefly is reading that charge line as a % of what is available from the Magnum invertor/charger, but I'll confirm with the EE at some point.

[bclemens]

As expected the Firefly isn't really set up to monitor the charge rate from the chassis. We will talk to them a out setting that to 0% when the charger is not available.

Best bet to see charging is on the Victron app which should display the amount of amps passing into the batteries.

[vlamgat]

Originally Posted by bclemens

As expected the Firefly isn't really set up to monitor the charge rate from the chassis. We will talk to them a out setting that to 0% when the charger is not available.

Best bet to see charging is on the Victron app which should display the amount of amps passing into the batteries.

Makes sense. It is confusing as presently set up. I think your earlier comment about the alternator regulator defining the amount of charge it will provide to the Coach (and the trailer if connected) makes infinite sense. A logic which completely bypasses the I/C and the Firefly.

It seems that this question has been of little concern to other owners yet I still wonder how this intel could be distributed for the future.

[bclemens]

I think many look at the gauge on their chassis dash, 14.4 volts, car starts. They ask does the alternator charge the house batteries? Yes. That's the last concern they give unless there is a problem.

Most people (I find) realize that the house charger is set up to charge the house batteries first and then then throw some at the chassis batteries when camping to prevent it from going dead. On the flip side most also realize the chassis alternator is set up to charge the chassis batteries first and then throw some of the extra at the house during transit. I don't think most people are worried about knowing all the details of how that happens....just that it continues to do so.

[toshu]

Victron app is my Electron god...

Originally Posted by bclemens

As expected the Firefly isn't really set up to monitor the charge rate from the chassis. We will talk to them a out setting that to 0% when the charger is not available.

Best bet to see charging is on the Victron app which should display the amount of amps passing into the batteries.

[V6TOY4X]

Balmar is the place for engine driven alternator charging of lithium
https://balmar.net/?product=regulator-mc-614-h


I would assume with a bit of patience and time to review the wiring harness, since the dual alt is an option. i would think you could disconnect the second alt from the dodge chassis and have it stand alone for the house lipo bank ran through one of balmars regulators.


All speculation, but I would give it a try if I didn"t have the option of a big solar array or genset and larger (100ampish) charger/inverter


Some light reading



https://livsailing.com/2019/11/04/pr...ng-to-lithium/


https://shop.pkys.com/alternator-lithium-battery.html

[TitanMike]

Originally Posted by V6TOY4X

Balmar is the place for engine driven alternator charging of lithium
https://balmar.net/?product=regulator-mc-614-h


I would assume with a bit of patience and time to review the wiring harness, since the dual alt is an option. i would think you could disconnect the second alt from the dodge chassis and have it stand alone for the house lipo bank ran through one of balmars regulators.


All speculation, but I would give it a try if I didn"t have the option of a big solar array or genset and larger (100ampish) charger/inverter


Some light reading



https://livsailing.com/2019/11/04/pr...ng-to-lithium/


https://shop.pkys.com/alternator-lithium-battery.html

Cheaper to just install a DC-DC charger like offerings from Renogy, Sterling, Redarc, etc.

Designed specifically for this type of application with no modifications to alternator charging system.

[V6TOY4X]

Originally Posted by TitanMike

Cheaper to just install a DC-DC charger like offerings from Renogy, Sterling, Redarc, etc.

Designed specifically for this type of application with no modifications to alternator charging system.

Ohh, missed all of this, thanks I love new gadgets.

[robo44]

Originally Posted by TitanMike

Cheaper to just install a DC-DC charger like offerings from Renogy, Sterling, Redarc, etc.

Designed specifically for this type of application with no modifications to alternator charging system.

x2 i installed DC-DC charger from Renogy, easy 60 min install

[V6TOY4X]

Originally Posted by TitanMike

Cheaper to just install a DC-DC charger like offerings from Renogy, Sterling, Redarc, etc.

Designed specifically for this type of application with no modifications to alternator charging system.

I just took a quick look at dc/dc they seem to be based on smaller output 30-40amps including victron? Am I missing something?


If you are running Lithium, isn't one of the big advantages their ability to take high amperage quick charging? If you have a 400-500AH bank limiting charge current to 30-40amps kind defeats the purpose??

[V6TOY4X]

Originally Posted by robo44

x2 i installed DC-DC charger from Renogy, easy 60 min install

what is the max charging current?

[TitanMike]

Originally Posted by V6TOY4X

what is the max charging current?

Renogy offers these in 20 amp 40 amp and 60 amp sizes. They recommend each size based on alternator sizes.

Most LiFePo4 batteries have a max charge rate of .5 C so you'd only want a 40 amp size unit for a single LiFePo4 100ah battery.

Lead acid batteries have their charge current taper off fairly soon and really only accept a charge rate of .2C to .3C. A DC-DC charger matched to your alternator size as recommended by Renogy, for example, would charge your batteries easily while driving from site to site without overloading anything.

They work as battery isolators and NO MOVING PARTS other than cooling fans. No Solenoids.

[V6TOY4X]

Originally Posted by TitanMike

Renogy offers these in 20 amp 40 amp and 60 amp sizes. They recommend each size based on alternator sizes.

Most LiFePo4 batteries have a max charge rate of .5 C so you'd only want a 40 amp size unit for a single LiFePo4 100ah battery.

Lead acid batteries have their charge current taper off fairly soon and really only accept a charge rate of .2C to .3C. A DC-DC charger matched to your alternator size as recommended by Renogy, for example, would charge your batteries easily while driving from site to site without overloading anything.

They work as battery isolators and NO MOVING PARTS other than cooling fans. No Solenoids.

So for a 4-500 ah bank that is not a solution if you are looking to take advantage of diesel dual alt setup with 400 amps available and do a quick top off in bad weather or if you hit a few days of no sun or don't want to run generator. They look like a good solution to insure proper top off while on the highway.

[TitanMike]

Originally Posted by V6TOY4X

So for a 4-500 ah bank that is not a solution if you are looking to take advantage of diesel dual alt setup with 400 amps available and do a quick top off in bad weather or if you hit a few days of no sun or don't want to run generator. They look like a good solution to insure proper top off while on the highway.

If you want more, you can, according to an Australian company Projecta, connect DC-DC chargers in parallel. Same type/size and you get up to double power. Need to size input wire for combined current draw. As for stage regulation, during bulk phase they just go " full throttle" and when approaching full charge they'll shut down to lower rate when each one's slightly different voltage is reached. On LiFePo4 there's usually only one voltage.

Yoy still need to follow max charge rate parameters for the battery type.

There's more info with a google search.

Things to consider, as stated wire sizes need to be adequate for each unit at its max draw, and cooling in space mounted needs to be adequate for twice the heat of one.

FWIW, two 60 amp Renogy units will cost less than a single smaller unit from Sterling, Redarc, and Victron.

For a 500 amp bank of Lithium batteries the max rate would be 250 amp and it would take just over 2 hours from dead to charged. How often would that large a battery bank be that dead? Two hours at 120 amp would be pretty noticable.

[V6TOY4X]

Originally Posted by TitanMike

If you want more, you can, according to an Australian company Projecta, connect DC-DC chargers in parallel. Same type/size and you get up to double power. Need to size input wire for combined current draw. As for stage regulation, during bulk phase they just go " full throttle" and when approaching full charge they'll shut down to lower rate when each one's slightly different voltage is reached. On LiFePo4 there's usually only one voltage.

Yoy still need to follow max charge rate parameters for the battery type.

There's more info with a google search.

Things to consider, as stated wire sizes need to be adequate for each unit at its max draw, and cooling in space mounted needs to be adequate for twice the heat of one.

FWIW, two 60 amp Renogy units will cost less than a single smaller unit from Sterling, Redarc, and Victron.

For a 500 amp bank of Lithium batteries the max rate would be 250 amp and it would take just over 2 hours from dead to charged. How often would that large a battery bank be that dead? Two hours at 120 amp would be pretty noticable.

Thanks, quite familiar with the intricacies of lithium and charging.
I have been running lithium for probably 6 years now, my current set up is 180AH CALB CELLS wired (4) cells in series (3) strings in parallel for 540AH 12volt nom bank with "B SMART" BMS. CALB CELLS, can charge at 1C and discharge at 2C.



4-250 watt 47volt panasonic residential panels, 2 strings of 2 panels in series so a 94volt system, through Magnum PT100 controller, magnum pure sinewave inv/chg (100amp) and the ME_ARC with specific charge setting for the calb cells. And a generator. Either of those having a max design of 100 amps. To do it again it would be all Victron hardware, no doubt.



I have a 5.9 cummins and my last step is going to be to copy the dual alt setup from the 6.7 as a standalone system just for the lithium pack. The intent is for redundancy to the generator and solar with the ability to provide a short charge cycle of 200+ amps for the "OH ****" day when for what ever reason your battery bank has left you high and dry.


I am aiming at a compressor based refrigerator that will not be a pain in the ass in the winter or camping in the mountains dealing with considerable amounts of shade and not wanting to listen to the generator for an hour each day. I have Mechman willing to build the alternator and have decided on the balmar external regulator based on marine applications and experience.


I had somehow skipped over DC/DC in my research, combing 4 or 5 of them in series does not make sense to me. Just like running multiple MPPTs vs one large one, however there are arguments that can be made for that.


Carry on, sorry for side tracking OPs thread.