New charging issue

[chs]

Hey y'all,
Well after my the (5 months old) AGM batteries went copluet. And now have 2 new lithium batteries in its place. (With a few hiccups) We are on our first trip. Come to find out that the house batteries are not being charged by the chassis. BUT when I press the button on the dash that is used to jump start with the lithium batteries, it does. My feeling is that the BIM is incorrectly wired. The only way I found this out is due to adding a battery shunt.
Probably why the original batteries went bad. They discharged 3 times to round 11.7 volts
Will look at it when we get home. Not messing with it on a trip.
All in all I believe we got most of not all the original issues taken care of. Mostly loose and incorrect wiring by Jayco. Oh and a bad (weak) 15 amp breaker for the converter.
That said. We love the RV. I averaged 12.8 mpg driving 63 mph. Drives great. Especially since I added the sumo springs front and rear. That should be a mandatory item on the EV chassis. NO more rolling/swaying. Feel totally safe now.

[RVfixit]

Originally Posted by chs

Hey y'all,
Well after my the (5 months old) AGM batteries went copluet. And now have 2 new lithium batteries in its place. (With a few hiccups) We are on our first trip. Come to find out that the house batteries are not being charged by the chassis. BUT when I press the button on the dash that is used to jump start with the lithium batteries, it does. My feeling is that the BIM is incorrectly wired. The only way I found this out is due to adding a battery shunt.
Probably why the original batteries went bad. They discharged 3 times to round 11.7 volts
Will look at it when we get home. Not messing with it on a trip.
All in all I believe we got most of not all the original issues taken care of. Mostly loose and incorrect wiring by Jayco. Oh and a bad (weak) 15 amp breaker for the converter.
That said. We love the RV. I averaged 12.8 mpg driving 63 mph. Drives great. Especially since I added the sumo springs front and rear. That should be a mandatory item on the EV chassis. NO more rolling/swaying. Feel totally safe now.

Hi, So when upgrading from Lead Acid or AGM batteries to Lithium, you need to make sure your converter is equipped to charge Lithium batteries. If not, the Lithium batteries will not charge fully and could be damaged by your old converter. Lithium batteries charge at a different rate than AGM or Lead Acid batteries. Before replacing your converter, look up the model and see if it has settings that can be changed to charge the Lithium batteries. Good Luck!

[SJ-Chris]

It could be that your solenoid was bad the entire time and that is what caused your AGM to not charge and ultimately degrade/die.


Good news....changing that solenoid is (usually) pretty easy and it isn't an expensive part. You absolutely want your engine alternator to be charging your house batteries. Especially if you don't have a generator or solar. BUT....

You may or may not need to install a DC-DC charger between your chassis alternator and your lithium house batteries instead of using that solenoid (so that your alternator doesn't get overused/abused). I'll let the lithium experts chime in on that one...


Good luck!
Chris

[chs]

1. My converter is a auto detect version.
2. As for the BIM, I am going to check it out. I don't think it's bad since when I press the button on the dash it's power it up and energizing the battery. If it was bad, it would not do anything when given 12 volts.
That tells me it's working. I think they have the wires backwards.
Right now I need to bring it to the Ram dealer to get things looked at.

[Mudfrog]

Originally Posted by chs

1. My converter is a auto detect version.
2. As for the BIM, I am going to check it out. I don't think it's bad since when I press the button on the dash it's power it up and energizing the battery. If it was bad, it would not do anything when given 12 volts.
That tells me it's working. I think they have the wires backwards.
Right now I need to bring it to the Ram dealer to get things looked at.

The batteries (chassis and house) get connected when you hit and hold the emergency start button. I'm not sure if the BIM even comes into play when that happens.

Also not positive about this but I've read on here that lithium batteries can really put pressure on a vehicle's alternator at times if they're added to a vehicle that wasn't set up for them from the factory.

[chs]

Originally Posted by Mudfrog

The batteries (chassis and house) get connected when you hit and hold the emergency start button. I'm not sure if the BIM even comes into play when that happens.

Also not positive about this but I've read on here that lithium batteries can really put pressure on a vehicle's alternator at times if they're added to a vehicle that wasn't set up for them from the factory.

The BIM is the solenoid. That is what directs the flow of DC from the alternator to the house batteries. The lithium version automatically closes and opens at roughly 15/30 minute intervals to charge house batteries without stressing the alternator .
Your correct about using lithium for starting.
The switch , I'm going to disengage afterwards.

[twinboat]

Standard converter/chargers don't harm lithium batteries, they just don't reach the higher voltage needed to charge then to 100%.


A BIM, standard ot lithium, is connected to the chassis battery and the house batteries. It serves as the boost start solenoid and as the bridging/charging solenoid between the batteries. The engine alternator is not connected to the BIM, just to the chassis battery, like a car. When the BIM closes, the charging chassis battery voltage is higher then the house batteries so they charge also.

[RVfixit]

Originally Posted by twinboat

Standard converter/chargers don't harm lithium batteries, they just don't reach the higher voltage needed to charge then to 100%.


A BIM, standard ot lithium, is connected to the chassis battery and the house batteries. It serves as the boost start solenoid and as the bridging/charging solenoid between the batteries. The engine alternator is not connected to the BIM, just to the chassis battery, like a car. When the BIM closes, the charging chassis battery voltage is higher then the house batteries so they charge also.

Twinboat, I will have to respectfully disagree with your statement about standard converters not damaging Lithium batteries- Below are some manufacturers guidelines for charging Lithium batteries-

Lithium battery chargers and lead acid chargers differ in a number of ways, including:
Battery type
Lithium battery chargers are designed for lithium-ion batteries, while lead acid chargers are designed for lead acid batteries.

Charging method
Lithium battery chargers typically use a constant current and constant voltage charge, while lead acid chargers typically use a constant voltage charge.

Charging speed
Lithium batteries can charge faster than lead acid batteries, sometimes in as little as a few minutes, while lead acid batteries can take over 10 hours to charge.

Safety
Lithium battery chargers often have built-in protection against overheating and overcharging, while lead acid chargers typically have a built-in thermal sensor to detect overheating.

Voltage
Lithium battery chargers have a higher voltage per cell and a narrower voltage tolerance than lead acid chargers.

Trickle charge
Lithium batteries don't have a trickle charge when they are fully charged, while lead acid batteries can become overcharged if left connected for too long.

State of charge monitoring
Using a lead acid charger to charge a lithium battery can be detrimental to the battery.

[chs]

Originally Posted by twinboat

Standard converter/chargers don't harm lithium batteries, they just don't reach the higher voltage needed to charge then to 100%.


A BIM, standard ot lithium, is connected to the chassis battery and the house batteries. It serves as the boost start solenoid and as the bridging/charging solenoid between the batteries. The engine alternator is not connected to the BIM, just to the chassis battery, like a car. When the BIM closes, the charging chassis battery voltage is higher then the house batteries so they charge also.

Yes I understand that the BIM is connected to the chassis battery. But both are being charged by he alternator.

[twinboat]

Originally Posted by chs

Yes I understand that the BIM is connected to the chassis battery. But both are being charged by he alternator.

The alternator charges the chassis battery.
The chassis battery is charging the house battery thru the BIM.

[chs]

Originally Posted by twinboat

The alternator charges the chassis battery.
The chassis battery is charging the house battery thru the BIM.

Using your logic, the battery charges the battery. So if I take the chassis battery and hook it directly to the house battery it will charge it. I THINK NOT. The chassis battery gets charged by the alternator. In turn that current go through the BIM (when it closes) then also charges the house battery.

[RVfixit]

Originally Posted by chs

Using your logic, the battery charges the battery. So if I take the chassis battery and hook it directly to the house battery it will charge it. I THINK NOT. The chassis battery gets charged by the alternator. In turn that current go through the BIM (when it closes) then also charges the house battery.

CHS, I think I understand what Twinboat is trying to say. For conversation sake, lets assume this is a truck and trailer. Naturally the trailer can't charge itself, it needs the truck system to charge the batteries. On a truck or motorhome chassis, as you know, the alternator charges the battery which in turn distributes the power to various things, one being the 12 volt charging wire in the 7 pin connector.

Even though you have a Motorhome, the same is true. You don't have a 7 pin connector but your alternator charges the chassis batteries at a rate 1 to 2 volts higher that battery voltage of usually 12.5v or so. The chassis batteries in turn supply your house converter, which charges your house batteries. (Its also true that your main alternator could charge both sets of batteries but not usually since you probably have a generator as well). The converters do various things over and above charging such as knowing what type of battery is being charged and converting either 120v to 12v or just passing through the 12v charge while driving. Whatever you have, it comes from the chassis batteries.

Now, some chassis have two systems, even two alternators. An alternator by nature produces 120volts and converts the voltage to 12 volts through a rectifier bridge. Some chassis have a second alternator that produces 120v directly to the converter but it doesn't seem that is what you have.

The switch on the dash should only be a momentary switch to connect all batteries together for emergency starting so holding it down or leaving in that position, you would only be reading the voltage average of all 3 batteries making it look like they are charging. My feeling is that your converter is not working/charging your new batteries and again, as you have already mentioned, more diagnosis is needed. Have a safe trip and good luck!

[Mudfrog]

Originally Posted by chs

The BIM is the solenoid. That is what directs the flow of DC from the alternator to the house batteries. The lithium version automatically closes and opens at roughly 15/30 minute intervals to charge house batteries without stressing the alternator .
Your correct about using lithium for starting.
The switch , I'm going to disengage afterwards.

I always thought the BIM was a box (electronic components) that automatically sent control voltage to the solenoid coil when it sensed a higher voltage from the engine's alternator. And that the emergency start switch, when manually operated, sent voltage straight to the solenoid coil. Didn't realize the solenoid itself was consider the BIM. Yep, still learning here!

[SafariBen]

Originally Posted by RVfixit

CHS, I think I understand what Twinboat is trying to say...

Except the chassis battery is NOT supplying the power 99.9% of the time that the BIM is charging the house battery, the alternator is. The current comes "from the chassis battery" only in the sense that that is the location of the large wiring connections that transfer power from the alternator to the BIM.



12v alternators produce AC power internally, typically around 20v maybe? definitely not 120V, and not 60hz, actually around 400hz which is a common military power frequency, but of course the alternator is not run constant speed so the frequency is wild.



" Some chassis have a second alternator that produces 120v directly to the converter but it doesn't seem that is what you have." can you give an example of one that uses this currently? I've considered it, as many inverters have a wide range of acceptable AC input, so that a "generator head" could be mounted on the chassis engine and supply higher voltage "variable hz" AC direct to the inverter/charger, bypassing 12/24/48v DC and letting an all in one inverter handle the charging, which it is already programmed to do.