converting from lead/acid to lithium and etc.

[Blacktank]

since i am to lazy for google and reading thought i would ask here

lead/acid is ancient and we all will be converting to modern tech sooner or later so how does this affect the lead/acid charging systems? 

the charge controller has a setting for lithium but what about the alternator or power converter/chargers? need to tone down the voltage or amps?

[Wayne49]

A battery to battery charger that can translate between lead acid and lithium, is my guess.

In the words of Offspring, "you've gotta keep em separated".

But what do I know, I'm still on the fence with the upfront $$$ commitment to Lithium.

Did you know (wrong thread) that 3,000 cycles (Battleborn) is over eight years, 4,000 cycles (Renogy) is almost eleven years. The Lithium batteries may outlive me, and I'd hate to die, leaving that unused capacity. Maybe the cheaper Chinese alternatives might be just good enough.

The Rich Solar 40A (and I think most current (in time) units) can do Lithium, if it is selected in the setup menu. Older solar chargers may not have the option.

[justjim]

I know that the culture lately has been to claim that the sky is falling and that there are alternators littering the highways from coast to coast from people charging their batteries. Like many the sky is falling claims this one comes with products to buy to prop it up. In fact a industry is being developed around it.

Motor home manufactures have been using the alternator to charge house banks for decades. Even without taking into consideration batteries like my old Lifelines that can suck up power faster than any lithium battery, there are large banks of lead acid that can suck up anything a alternator can produce. Specialty chargers like DC to DC or isolators like the LIM-225 were never needed for those banks.

In that light I have been installing a simple Isolator called the battery doctor every since I have been installing lithium and not once in four years has the sky fallen on any of my customers. The one safe guard you may want to consider is a disconnect switch that allows you to chose to not charge from the alternator while just idling or sitting in city traffic with the rpm of the engine low. High demand and low RPM can be stressful especially considering that there is low airflow for cooling at the same time.

[justjim]

Wayne

Remember that those high cycle numbers come from light discharges. Just like with lead acid the deeper you discharge, the bigger the bite out of the lifespan.

Any controller that will accept custom user settings can be used for Lithium. Not only do you need to turn off the temperature compensation but equalizing as well because either will attempt to raise the voltage.

A big advantage to the Victron controllers is the Bluetooth voltage/temp sensor that can tell the controller to not charge when the temperature of the battery is at freezing or below.

[Blacktank]

i have a toggle so i can turn alt house charging on/off at will,my concern is the alt will for a short time pump out 14.6-14.8 volts and have heard that lithium's dont like the higher voltages,same with my power converter with the charging algorithm in but i can disconnect that and it will be 13.6? v constant

i have been seeing people just replace their lead acid with lithium and charge it by alt,me thinks there should be an in-between voltage regulator for lithium? or not?

cycles dont matter if you smoke your battery

[justjim]

Check the alternator output not just at the starting battery but more importantly at the bank to be charged. You might find that line loss takes care of any high voltage issues. You will need a converter such as a DC to DC charger if it's too high because isolators only use voltage to turn on and off. Even the lithium built BIM 225 will only stop charging if the alternator voltage gets too high. It's advantage over a DC to DC charger is that it uses timed intervals of charging and not charging to allow the alternator to cool down.

Only once have I seen the voltage from a alternator too high and that was for a instant before the voltage regulator kicked in. Cheap charge controllers will allow the voltage to climb too high during cloud effect for seconds before they cycle and knock it back down. Long enough to shut down a inverter due to the voltage going over 15 volts.

Remember that the purpose of the BMS is to keep the battery from being smoked.

[sternwake]

With No experience with cycling Lithium, other than phones or powertools, I am reluctant to engage this thread.

Every charging source I employ, has a voltage control dial, or in the case of my SCC, buttons.

None of those I employ, have a dial for amperage, though the voltage dial can accomplish the same thing indirectly, but an Ammeter is vital.

With a well depleted lead acid battery at 12.1v, I can hook up my 100 amp adjustable voltage charger, set to 12.11, and only 0.1 amps flow, yet if I crank up the electrical pressure/voltage dial amps start climbing towards that 100 amp limit of the power supply.

The healthier and lower resistance the battery, and the more depleted it is, the more it accepts when the pressure is cranked up.

With NO experience applying a 100 amp adjustable power supply to a lithium battery, I wonder how different the amperage acceptance changes when cranking up voltage.

say I set it to 13.4 when well depleted, the lead acid battery might be accepting 37 amps, but the same capacity of lithium would be accepting what, 100?

What if the BMS sees more than its potential 50 amp limit, and opens the charge circuit....If I was using my alternator and the field current to rotor was not also instantly cut, poof go the diodes in the alternator.

I personally do not want to be limited in charge amperage. With short drives to ocean, or grocery stores, I want as much amperage to flow into depleted batteries as possible, at a target voltage of my choosing.

My 22 month old lead acid group 31Northstar AGM recently, by itself, recently accepted 116 amps from my alternator, and could have accepted more, if more amperage was available. When it was newer and well depleted, 134 amps of parallelled power supplies, was not enough to instantly bring it to absorption voltage

But with lead acid, 80% to 100% when discharged well below 80%, is no less than 3 hours no matter what, and 100% better be achieved regularly or those batteries are going to shrink quickly.

I am not sure what I would have to do to employ Lithium in my rig. I can spin a dial and change target voltage, but the BMS might have ability to override, and perhaps fry the diodes in my alternator, or something in my plug in power supplies when it decides the charge current is not acceptable and disconnects it.

The voltage allowed by many modern vehicles today, is much more about maximizing potential fuel economy. They will crank back alternator output via voltage regulation, when it is most advantageous to accumulating miles per volume of fuel burnt, then crank up voltage, thus amperage, with each 25 alternator amps sucking up ~1HP from the engine when it is advantageousd to do so, for mpg.
Such vehicles keep the battery in the 80% charged ranges, so that when voltage is cranked up, the battery can accept high amperages.
This of course is horrible for the lead acid battery, but automakers are not rewarded for battery longevity, as they are fuel economy.

Many modern GM vehicles will take system voltage well above 15, and this is more likely in cold temperatures.

Some of my concerns can likely be dismissed, I have several years of Lead acid battery lifespan before I really need to dismiss those myself, and optimized for lead acid, I might stick with it at that point.

if Lithium keeps taking more and more of the cycling battery market, perhaps lead acid price will drop.
perhaps more cycling lead acid can be developed, Firefly style, where partial state of charge cycling becomes less detrimental to cyclelife.

But I do feel the need to acquire experience cycling Lithium before then.
I'm thinking about smaller prisimatic cells to use as a hybrid/portable system, rather than a battleborn style 'drop in' whose BMS might want to fry my Diodes.

Right now my 12 or 12v portable requirements are easily met with my 18 and or 22Ah AGMs.

Where my extension cord could not reach, my 800 watt MSW inverter in my backpack with the 18Ah AGM, were able to power amp 8 amp leaf blower on low speed, or my mini shopvac.
The capacity per weight of Lithium in this application would be far superior.

[Tom_M]

I've had my Renogy 170ah lithium battery for two years and the only thing I've done is to upgrade my solar charge controller. So far no ill affects from charging by alternator.