Dropped in Lithium Batteries

[Bullitt6283]

Originally Posted by Bullitt6283

Have you ever had an issue starting the generator with the single lithium battery?

Originally Posted by Flight Control

I was surprised by that question. It never crossed my mind that Lithium would present some kind of cold crank issue. Did you come across something in the blogosphere that suggested such? But to answer your questions, no that's never been an issue. In fact, after reading your post, I hit the start button just to confirm. It was a strong kick, and it started in about 3 seconds.

I was just checking. The Battle Born lithium battery warranty takes exception to engine starting.

I assume this means vehicle engines, but I wanted to be sure.
Thanks!


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[pokergeist]

Originally Posted by Bullitt6283

I was just checking. The Battle Born lithium battery warranty takes exception to engine starting.

I assume this means vehicle engines, but I wanted to be sure.
Thanks!

I asked BB about this issue before I bought, and I believe the exception was to "repeated engine starting". I mean, my generator has an engine, and I figured I'd probably start it using the house batteries at least twice, so I wanted to know where I stood before I bought. They had no concern about generator starting with regard to the warranty. I suggested that they clarify that in their warranty document.

[Bullitt6283]

Originally Posted by Flight Control

..... Then I set about to find out which cable on the solenoid was the house, and which was the alternator. After I determined which one it was, I isolated it from the solenoid, started the engine, and measured the voltage to ground. It don't recall the exact value, but it was significantly less than the 14.4v that Lithium needs to keep it boosted to 100%. I presumed that the voltage diff is the reason why Renogy doesn't recommend Lithium in the RV house. Take away the link to the alternator, and there's no difference between the house Lithium battery and any other Lithium application in a solar-powered home. Maybe I'm missing something here. If I am, I hope somebody tells me before I blow something up.

From what I've been able to glean from various sources....

It's my understanding that some coaches use a Battery Isolation Manager (BIM) which charges either the coach or chassis battery if either alternate one is being charged. It is a bi-directional and assumes both chassis and coach batteries to be the flooded type or similar chemistry.
So if the coach battery is lithium, since its normal resting voltage is higher, even though it's not being charged, the BIM may hook it to the chassis battery anyway. That would tend to drain the lithium coach battery.

In other coaches like my Class C, the coach and chassis batteries are tied together by a solenoid only when the chassis engine is running (or the jump switch button is pushed). With the engine running, if the alternator is supplying less voltage than the lithium battery has, the lithium battery may try to charge the chassis battery. In cold weather the alternator may be commanded to supply a voltage higher than the 14.4 volts the lithium battery likes. In this case the lithium battery may be overcharged by the alternator.

A special BIM like the Precision Circuits #00-10041-260 is made for the situation of lithium coach batteries and flooded chassis batteries.
https://battlebornbatteries.com/shop...ation-manager/



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[pokergeist]

Originally Posted by Flight Control

Clearly you know far more about the technicals than I do. I don't really know which solenoid part it is.

A little background: I like Lithium so much, I quickly moved ahead to replace the house AGM battery without doing much research. I was talking to Renogy techs on a different subject and I asked them about replacing AGM with Lithium in the house (after I had already done it.) They said it is not recommended because of the alternator voltage. I think I mumbled something like "Oh $&*t" and hung up. Then I set about to find out which cable on the solenoid was the house, and which was the alternator. After I determined which one it was, I isolated it from the solenoid, started the engine, and measured the voltage to ground. It don't recall the exact value, but it was significantly less than the 14.4v that Lithium needs to keep it boosted to 100%. I presumed that the voltage diff is the reason why Renogy doesn't recommend Lithium in the RV house. Take away the link to the alternator, and there's no difference between the house Lithium battery and any other Lithium application in a solar-powered home.

Maybe I'm missing something here. If I am, I hope somebody tells me before I blow something up.

When you started your coach, did the chassis battery(s) needed a charge - hence the low voltage initially? I don't think that having the BIM connect the two battery sets would cause a problem - other than charging your chassis battery with your house batteries. I think your mod to the solenoid was a good move.

It also eliminates the running chassis electrical system's noise and ripple from effectively creating micro charge/discharge cycles, which may negatively affect Lithium battery life ... though what I read on that issue was not quantitative or conclusive.

Finally, it's not necessary to top off the Li batteries off every time. Do so periodically to equalize the cells of course, but you may get a little more battery life otherwise.

If you can post a picture of your solenoid/relay/BIM I'm sure someone here can identify it. Cheers!

[Jeff Evans]

Originally Posted by AKGperson

I'm thinking of replacing my lead acid deep cycle batteries with Battle Born Lithium batteries. Battle Born calls their batteries "drop in replacements". My question is, have you swapped out for Lithium batteries and, if so, did you switch out the Jayco-installed controller/charger as well? My understanding is that the original charger will charge them but not to 100%.

I replaced our lead acid battery with a Battleborn battery. I talked to Battle Born and Prgressive Dynamics about the stock charger in the distribution panel. It works fine. There is a jumper on the charger board you can move to LI (lithium). But you don’t have to. I did to ensure the battery was fully charged. (14.4 volts).There’s a built in battery management system for lithium battery that protects the battery from over charging. Remember the generator on engine also charges the house battery.
I insulated the battery compartment since it was open to the outside air. I was concerned about the cold. The Battle Born guy said that was good.
The Battle Born folks are great to work with.
Hope that helps.

[Bullitt6283]

Originally Posted by Jeff Evans

...I talked to Battle Born and Prgressive Dynamics about the stock charger in the distribution panel. It works fine. There is a jumper on the charger board you can move to LI (lithium)......

What is the model number of your Progressive Dynamics charger?


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[Jeff Evans]

Originally Posted by Bullitt6283

What is the model number of your Progressive Dynamics charger?


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I have the original converter in our Melbourne. It’s a model PD4060K.

[Jeff Evans]

Originally Posted by Bullitt6283

What is the model number of your Progressive Dynamics charger?


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Progressive Dynamics has a great website and you can call them. The installation and user guides are also on their website.

[Rvorbust]

I have been looking at BB lithium’s for a while now for replacement of my Greyhawk 29MV FLA battery. My biggest concerns are with the BB’s interaction with the alternator. LifePO4 batteries can accept charge at a much higher rate than FLA batteries, potentially causing overheating and high stress to the alternator. According to BB tech’s, I can simply do a drop in if using only a single BB battery and not stress the alternator. If using 2 or more, they recommend using a battery isolation manager from Precision Circuits which they sell. Have any of you had alternator issues since going to lithium?

[Flight Control]

When I went to Lithium on my Greyhawk 29MV, I had not heard that caveat about stressing the chassis inverter. That makes sense, but it didn't factor in anyway, because I dropped in a single 100ah lithium 12v. However, I was warned by Renogy that the chassis alternator does not charge at the higher voltage that Lithium needs to come up to 100%. So, I disconnected the house battery from the Battery Isolation Manager under the hood. No harm doing that. It simply means that the lithium will be charged from the house generator OR when connected to shore power. And THAT assumes you have replaced your stock inverter with a model that supports lithium. I don't remember the Progressive Dynamics model I went to, but it doesn't matter since PD has new lithium converter models now. I plan to connect the chassis alternator cable back on the BIM via a manual switch. So, if I ever need help starting the chassis engine, I can simply "flip" the switch to join batteries for a start boost.

Is that clear as mud?

[Jeff Evans]

Originally Posted by Rvorbust

I have been looking at BB lithium’s for a while now for replacement of my Greyhawk 29MV FLA battery. My biggest concerns are with the BB’s interaction with the alternator. LifePO4 batteries can accept charge at a much higher rate than FLA batteries, potentially causing overheating and high stress to the alternator. According to BB tech’s, I can simply do a drop in if using only a single BB battery and not stress the alternator. If using 2 or more, they recommend using a battery isolation manager from Precision Circuits which they sell. Have any of you had alternator issues since going to lithium?

I’ve got the Battleborn battery and I’ve never had any issues with the alternator. Remember the BB battery has a battery management system that protects it from overcharging or charging when the temperature is too cold. Lithium batteries cannot be trickle charged so charging from the alternator or charging from the shore power converter could damage the battery if it didn’t have a battery management system.

[JesseS]

A lead acid battery charger (or your alternator) tops out at 13.8 volts, which for most LiFePo4 batteries will only charge to 80-90%, these batteries take 14.6 constant voltage & constant current, letting the built in BMS (battery management system) control the charge rate. When I went to Lithium I also changed the OEM dumb charger to a PD Lithium converter/charger with only two charge rates, 14.6 and 13.8 for float.

[Rvorbust]

Originally Posted by Jeff Evans

I’ve got the Battleborn battery and I’ve never had any issues with the alternator. Remember the BB battery has a battery management system that protects it from overcharging or charging when the temperature is too cold. Lithium batteries cannot be trickle charged so charging from the alternator or charging from the shore power converter could damage the battery if it didn’t have a battery management system.

Thanks for the reply Jeff. I’m not concerned with the BBs being overcharged, but with the alternator being overtaxed. Lifepo4’s can and do accept charge at a much higher rate than Lead acid batteries. If the alternator isn’t designed to deliver this higher current it could lead to future problems with the alternator. But I wouldn’t expect it to fail quickly, just shorten its life. Having said that, how long have you had your BB’s installed?

[JesseS]

LiFePo4 Lithium batteries can accept up to their rated capacity in charge current if available, the batteries cannot draw more current than the alternator can provide, so will not damage your alternator.