I just bought Lithium… now what?

[Dean_Reynolds]

Hello RVer’s and smart people. Thank you in advance for their wisdom you might share!

Just bought a weinz 100Ah lithium battery. What do I need to do for crossover of the coach/ battery maintenance?

I have already contacted progressive dynamics for questions on the converter (Pd4655)— it’s as simple as a jumper on this one.

I think my main question is do I need to adjust anything on the 7-way coming out of the truck? I think the alternate battery charger on that plug is only 12.9v?

 

[IBTripping]

I don't think you have to do anything. While traveling, your truck will keep the battery charged. The truck alternator won't be setup exactly for Lithium, but not a big deal and won't do any damage to the battery.

 

[Mark_K5LXP]

Practically speaking you probably don't have to do anything. Technically an alternator would have a hard time charging lithium due to the mismatch in design voltage, but when you factor the distance from the alternator to a trailer battery through a set of connectors, the voltage drop through the wire will likely even things out. The lithium may not charge 100% from the TV but it's not going to burn up the alternator either. Some time spent with a voltmeter in the driveway with the battery at different states of charge will give you an idea if you need any kind of charge control or not.

Mark B.
Albuquerque, NM

 

[Ex-Calif]

Hello RVer’s and smart people. Thank you in advance for their wisdom you might share!

Just bought a weinz 100Ah lithium battery. What do I need to do for crossover of the coach/ battery maintenance?

I have already contacted progressive dynamics for questions on the converter (Pd4655)— it’s as simple as a jumper on this one.

I think my main question is do I need to adjust anything on the 7-way coming out of the truck? I think the alternate battery charger on that plug is only 12.9v?

Depending on the vehicle the alternator is likely putting out 13.5V or so.

Regardless of Lead Acid or Lithium the alternator is not a 3-stage charger and will just push amps based on state of charge. As IBTripping says, won't do any harm.

You on-board charger can/should do the job of final charging to get max SoC on the battery.

 

[Gary RV_Wizard]

Depending on the vehicle the alternator is likely putting out 13.5V or so.

Most automotive alternators are regulated to the 13.5-14.4 volt range. Voltage drop to the trailer connector and from there to the trailer battery varies all over the map, but 0.5v would be a reasonable estimate (check it with a voltmeter).

As others have said, it's hardly worth worrying about the alternator voltage unless you are relying on the driving time between stops as the sole means of battery charging. The typical alternator voltage should be sufficient bring a lithium battery up to at least 80-90% capacity

 

[Dean_Reynolds]

Awesome, thanks guys! So, if my only source of charging for a couple days is the tow vehicle, and, I’m pushing out 12.9 (if memory serves), sounds like I’m OK with lithium… It’s just going to cap out at 12.9?

 

[Mark_K5LXP]

If your alternator is only putting out 12.9V then there's probably something wrong with it. Even "smart" alternators only go down to the high 13's, most are sitting at 14.2 especially right after starting.

Mark B.
Albuquerque, NM

 

[DonTom]

Awesome, thanks guys! So, if my only source of charging for a couple days is the tow vehicle, and, I’m pushing out 12.9 (if memory serves), sounds like I’m OK with lithium… It’s just going to cap out at 12.9?

I hope you mean 13.9 volts!

If you want to be sure you get a full charge to your lith batts when you're driving, you can add one of these thingies, like I did in my Y2K RV.

-Don- Reno, NV

 

[Lou Schneider]

Seeing 12.9 volts at the trailer batteries isn't unusual for a trailer. due to the length and small gauge of the wire between the vehicle alternator and the battery 30 ft. of 12 gauge wire between the tow vehicle's alternator and the trailer battery will lose about 1.2 volts at 20 amps.

 

[DonTom]

Seeing 12.9 volts at the trailer batteries isn't unusual for a trailer.

OIC. But he said "pushing out" not 'pulling in' so I assumed it was measured at the other end.

Another good reason to use the DC2DCC as shown above--at the trailer end of the line and get the proper voltage to charge a lith.

-Don- Reno, NV