New Boondocker converter test

You don't need 4/0 for 170 amps unless you have really long run of wire (like 20+ feet). #2 will handle 210 amps.

From the Bai-ology website:

"Scientists Use a Mutated Virus to Build a Better Battery

By unleashing a genetically modified virus onto microscopic electrode wires, researchers from MIT have shown that the performance of lithium-air batteries can be significantly improved — a remarkable breakthrough that could revolutionize the way our electric devices are powered.

Indeed, lithium-air batteries have generated considerable buzz over the years because of the way they can increase power without having to increase weight, an attribute that could lead to electric cars with much greater driving range. But engineers have struggled to to create the durable materials required for the batteries’ electrodes, and increase the number of charging-cycles the batteries can withstand.

To overcome these limitations, researchers from MIT demonstrated that by adding bioengineered viruses to nanowires during the production stage — tiny electrode wires about the width of a red blood cell — some of these problems could be alleviated.

This virus, called M13, works by increasing the surface area of the wire, which in turn increases the area where electrochemical activity takes place when batteries are charged or discharged.

In a process similar to how an abalone pulls calcium from seawater to grow its shell, the nanowires, with the help of the M13 virus, pulls molecules of metal from room-temperature water, which the virus then binds into specific structural shapes. Specifically, the viruses produce manganese oxide wires — and they have the rough, spiky surface required for the desired increase in surface area.

The final part of the process involves adding a small amount of metal, namely palladium, to increase the electrical conductivity of the nano wires.

Taken together, these modifications show that it may soon be possible to create a fully functional battery with an energy density that’s two to three times greater than today’s best lithium-air batteries — the energy density being the amount of energy that can be stored for a given weight."

I am Borg... Resistance is futile.

A General Motors 454 engine used a 10MT Delco for many years. Average 250 amperes starting. A Ford 7.3 diesel used a pair of batteries and a 27MT Delco starter for many years. Average 400-500 amps draw.

If a 140 ampere alternator needs 4/0 cable to charge, it will take cable the thickness of my wrist to start a 454, and cable the thickness of a can of tomato juice to start the 7.3

What's wrong with this picture?

"and of course there's plenty of other places to spend new-charger-just-for-the-geek-fun-of-it money on."

yep... like the local gas station.

http://www.powerstream.com/SLA-fast-charge.htm

I doubt VW was trying to feed 170 amps into the AGM. Is the cabling 4/0? didn't think so.

I think these higher rated output alternators are merely for more overhead safety margins.

My 130 amp alternator, by my observations, could likely reach that output, if I put the second V belt back on, and revved the engine to 4000 rpm when cold.

When hot at 550 idle rpm, the thing can only make ~30 amps. This is with an undersized pulley.
If I have my blower motor on high and the headlamps on, 10 amps are flowing from my battery to make up for what the alternator cannot provide

I've seen my screwy 31 take well over 70 amps from the alternator, I've seen my Northstar group 27 AGM take well over 90.

Not sure of the durations that these could accept these rather extreme currents. My Ammeter is not on the dash for easy observation, and once my alternator heats up is it not capable of delivering them anymore.

jrnymn7

Right On The Head!

Voltage is key. Yes, batteries luxuriate with a 10% of amp hour rating recharge amperage rate. When suckling from a power post for days on end, this is the way to treat batteries best.

But apply maximum REGULATED voltage to the battery charges them at the fastest SAFE speed. As BFL13 often points out with his graphs, the last 20% of charge capacity is the hardest to achieve. Some folks don't mind running a generator eight hours to recharge a couple of batteries. Other folks including me cannot do this. For some it's hours of operation limitation. For me it's money. Four dollar a gallon diesel and an eight thousand dollar engine.

Senor Niner, your scrubber battery is true deep cycle. Thicker plates than even a golf car battery. Very dense plate paste. Very low CCA capability (less than a single pseudo deep cycle 24). So it's charge acceptance is going to be less pound for pound than many other "lesser" batteries. Of course CCA is not what you are looking for in a scrubber battery.

Let me put it this way... the AGM battery in my VW Touareg TDI diesel is a Group 48 I believe. Alternator has a 170 Amp rate output. No idea how fast that battery takes a charge. But an alternator that powerful, the goal appears to be to recharge that battery rather quickly.

"My two paralleled 12 volter AGMs will only suck around 50-60 amps for a very short time from the alternator's 14.XX."

According to the manufacturer, you'd be best to take better notice of the .XX v on those agm's... or you will over charge them.

If they are only accepting 50-60 amps at 14+ volts and 50% soc, that is an indication of the alternator's output, not the banks ability to accept current.

A single T 1275, 150 AH rate, at 40% SOC 12.0V, will easily gobble 33 Amps at 14.8V from a Power Supply Unit for close to 2:00 before the amps drop to a 9 amp/hr charge rate to finish it off. What % SOC it is at after 2 hours is anyone's guess, but I'd say the battery is 40-50% bigger than a Group 29 or 31.

If you pop the covers, in the last 1/2 hour, you will see the absolute finest of tiny, tiny bubbles, barely visible to the naked eye. They usually stick to something instead of overcoming surface tension and floating to the surface, unless they get big enough to pop free and float up.

The above procedure is for dry camping purposes where running a generator and wasting gas charging inefficiently is a major consideration. Add in Solar panels for the slow amp take rates above 85% SOC to top things off fully.