Thread: Lithium Crank Battery

Just been doing some research on lithium batteries and found this video from Victron quite interesting:

Careful - Alternator Charging Lithium - Victron Energy

A few misnomers and holes in the info I think but they do have a lot of good info and there’s a lot of words with the letter ‘r’ for the compere to westle with

Im very stoked to have bought a big 900cca / 75AH yellow top and a 1000cca 120 AH deep cycle for under $600 on sale.
(I very nearly bought a $500 Kings lithium but decided I couldn’t be bothered to re jig my current setup that’s worked so well for so long!)

Hopefully my next battery purchase will be something a lot bigger - to drive the wheels ⚡️

Hi Colmoore, that is the second video on “How to burn out an alternator” put out by that mob and it is as equally dishonest as the first.

I have never used any of their products and up until some customers of mine sent me links to the first video, I was interested in their gear, but once I saw the first video, and this one just confirms my opinion of the company, there is no way I would now trust anything that company had to say about any of their products.

First off, why didn’t they use identical alternators for the two tests? One without the reducer and one with it.

Secondly, it would be almost impossible to imitate that bench test in real life.

If you wanted to try to imitate the same situation in real life, you would have to operate the alternator in a situation that was never intended by either alternator manufacturers or vehicle manufacturers.

The fans in any alternator are not sufficient by themselves, to cool an alternator when working hard.

All alternator manufacturers rely on air being forced through the alternator because the vehicle is in motion, in other words, while the vehicle is travelling down the road.

And when the vehicle motor is at idle, say in traffic, first off the alternator will be at low revs ( not working very hard ) and the radiator fan will still be forcing a high volume of air through the alternator, regardless of whether the alternator has internal fans or not, and this will keep the alternators temperature within specs.

So to imitate their dishonest bench test in real life, you would first have to remove the radiator fan blades or disengage an electric thematic fan.

Then you would have to idle up the motor to get enough revs at the alternator for the alternator to be able to produce that high current.

If you were to try this, you would more than likely cook you motor way before you “burnt out” your alternator.

Last but not least, any alternator being operated as the manufacturers intended, can NOT be “burnt out” by applying a current load greater than what the alternator can produce.

The reason for this is that all alternators, by their very operation, are self-protecting against current overload.

When ever a current load is applied to an alternator that high than the alternator can produce, the alternators voltage reduces until the applied current load equals the alternators maximum current output.

Just like lead acid batteries, when you reduce the charge VOLTAGE applied to a lithium battery, a lithium battery will pull less CURRENT from the charging device.

I have many customer who have 2 batteries under the bonnet and up to three large batteries in their camper trailer or caravan, and after being camped for a few days, will drive to their next camp spot.

And starting out with low batteries, they may drive for three, four or five hours straight and their alternator will be working full bore the whole time.

This does not burn out the alternator, it simply charges all the batteries faster than any other setup.

BTW, this is the very reason SMART alternators operate at much lower voltages. By doing so, they lower the load on the motor, which means the motor uses less fuel and thus, lowers its exhaust emissions.