200 Amp Generator to charge power bank

[Hummer Guy]

Does anyone know if the humvee generator is able to charge another battery besides the starting battery? I'm about to put together my solar battery bank on the humvee and was wondering would it be possible to also wire the battery to the generator and have it charged that way. I do not want to wire it with the starter batteries so I won't have to worry about it draining those.

Also, is there's a way to charge the battery at 12v instead of 24? If not, its fine since I have no issue running a 24v system. I doubt this would stress the generator any with the size of the 200Amp generator, I'm assuming it won't do much with the 60 amp either right?

 

[Sigi]

To charge an additional house battery off the same alternator, I'd use an "automatic charging relay". This relay will only connect the second battery when the voltage is at charging level (>13V). It will automatically disconnect when you turn off the engine.

A diode works also but at 100+ amps it may not be much cheaper than the relay. Also, it induces a 0.7V voltage drop-not ideal.

24V setup would be easiest unless you have a dual voltage alternator.

 

[Mogman]

how big are your solar batteries and what is the reason for installing the solar system on a HMMWV? (other than charging the vehicle batteries, just curious)
The simple answer is yes it can charge other than the vehicle batteries, you just need to figure out how you want to isolate them, switch, relay depending on how you want to operate it.
Your 200A system can also charge 12V batteries but I would not push it more than just a few amps., the 60A no 12V

 

[Hummer Guy]

how big are your solar batteries and what is the reason for installing the solar system on a HMMWV? (other than charging the vehicle batteries, just curious)
The simple answer is yes it can charge other than the vehicle batteries, you just need to figure out how you want to isolate them, switch, relay depending on how you want to operate it.
Your 200A system can also charge 12V batteries but I would not push it more than just a few amps., the 60A no 12V

Im either going for a 200ah or 300ah lithium battery. I currently already have 3 600w solar panels. The plan is to use it for a backup generator and power supplies around the shop.

I may end up going with another 600w panel if I have the space to fit it nicely

 

[Mogman]

OK, you said " I'm about to put together my solar battery bank ON the humvee" so I was wondering, you can just make a slave cable to charge the batteries

 

[Hummer Guy]

OK, you said " I'm about to put together my solar battery bank ON the humvee" so I was wondering, you can just make a slave cable to charge the batteries

Interesting idea, didn't think of that

 

[BLK HMMWV]

Interesting idea, didn't think of that

You also should do some research on charging lithium-ion batteries. they charge differently than AGM's and standard lead acid do with a standard
automotive style alternator generator.

 

[TOBASH]

As the Black knight says, they charge differently. Without a charge controler you can and possibly will burn your house down.

 

[Sigi]

Mixing battery technologies complicates things. As pointed out above, you have to follow the appropriate charging protocol.

The easiest way is to use a DC-To-DC charger that is set up for Li-Ion. Down-side is slow charging which negates one of the Li Ion advantages. The DC-DC charger will only pass amps up to its rating. The DC-DC charger will also protect the alternator against overload. A deeply depleted Li Ion battery draws a lot of current, essentially behaves like a short.

Btw, don't use Li-Ion as the starting battery. When the BMS disconnects due to overvoltage it will destroy your alternator.

 

[Hummer Guy]

Mixing battery technologies complicates things. As pointed out above, you have to follow the appropriate charging protocol.

The easiest way is to use a DC-To-DC charger that is set up for Li-Ion. Down-side is slow charging which negates one of the Li Ion advantages. The DC-DC charger will only pass amps up to its rating. The DC-DC charger will also protect the alternator against overload. A deeply depleted Li Ion battery draws a lot of current, essentially behaves like a short.

Btw, don't use Li-Ion as the starting battery. When the BMS disconnects due to overvoltage it will destroy your alternator.

Interesting, would the same apply for normal deep cycle batteries?

 

[Coug]

Interesting, would the same apply for normal deep cycle batteries?

For the most part, deep cycle are lead acid batteries. Some are AGM, some are flooded cell. They are usually close enough that you can charge them the same if it isn't the primary charging method for long term usage. You won't get optimal life charging with the wrong method, but it won't be a catastrophic reduction either.
There is enough resistance in the design that you don't usually need to worry about killing an alternator when charging them from fully discharged, though I've seen it happen a couple times in automotive applications where dead/dying batteries took out alternators after extended periods of time (and a few jump starts)

True deep cycle batteries shouldn't be used for starting because they aren't designed for that type of heavy draw on them and can be damaged.
Marine or RV deep cycle are just slightly modified cranking batteries that aren't the best for either application, but survive better in both starting and deep cycle use compared to using a starter for deep cycle or a deep cycle for starting.

 

[wheelspinner]

If you’re interested I have 500 amp battery isolators available for sale.

 

[blutow]

Im either going for a 200ah or 300ah lithium battery. I currently already have 3 600w solar panels. The plan is to use it for a backup generator and power supplies around the shop.

I may end up going with another 600w panel if I have the space to fit it nicely

If you are going lithium (lifepo4), you really want a DC-DC charger to manage current demand on the generator and also control the voltage output and charge profile. A 24v lithium battery isn't going to explode if you hook it into the hmmwv charging system. It has an internal battery management system that will disconnect once it exceeds a certain voltage or current, but it can cause problems with the charging system and won't be doing the battery any favors. The DC-DC charger should be sized so that it doesn't pull more than the rated amps for the generator at idle and also netting out any other loads. You also don't want the charger putting out more amps than your battery can handle (also considering the solar charge output if they will be charging at the same time). The capacity of the battery (200ah, 300ah, etc.) doesn't tell you what the max charge and discharge amps are. Many are limited to 100a or lower.

 

[Hummer Guy]

I decided to go with the deep cycle batteries, which ones do I need to wire up to charge the batteries at 12v? I have the dual voltage generator, I'm still undecided on whether I'm going to wire my batteries in 12v or 24v

 

[Coug]

So if the bank isn't living in the HMMWV, then charging it via the slave plug is going to be the simplest/easiest solution.
That would necessitate having the bank as 24V.

Unless you have gear that operates on 12V only, then it's almost always going to be higher voltage for battery banks. The bigger the bank, the higher the voltage (within reason)

Trying to charge on 12V the generator 12V output is only rated to 50 amps
12V x 50 amps is 600 watts of power available
The 24V output is rated at 200 amps.
24V x 200 amps is 4800 watts of available power

(you don't really want to max out the generator as that can shorten it's life if done for too long, so try to keep under 80% or so, which would be about 500 watts and 4kw respectively)
Actual voltages are a little higher (approx 14V and 28V) so it's actually slightly higher, but you get the idea.

As for the actual batteries themselves, that depends on what you want to spend and how big of a bank you want/need.

You'll likely want to go 6V batteries to start, unless you want to invest a lot more money and space into this system.

Golf cart batteries are relatively inexpensive, and for a non-critical system they are a great set for learning how to take care of them, because if you screw up you aren't out nearly as much money. Trojan is the go to brand usually and price reflects the quality, but Duracells aren't a bad deal to start out for learning for a whole lot less money.
Number designation is usually GC2 or something similar (I've seen XC2 as well, or added letters added to the end)

Group 902/903 series are the next size above the golf carts. About 50% more capacity and 50% more size.

Next above that is the L16 format. About twice the physical size of the GC2 and twice the capacity.

All these are relatively common industrial battery sizes, used in things like floor sweepers/scrubbers you see inside stores and whatnot.
Downside is having to check fluid levels about once a month and keeping them topped off with distilled water.

For more money you can buy AGM type batteries. These are nice that they don't really require any maintenance other than checking the terminals for corrosion and tightness every once in a while.
Price is about 50% higher than the GC2 batteries, and are expected to last maybe 20-30% longer overall compared to the GC2.
Nice because you can mostly ignore them until something goes wrong, but more upfront cost.



As I mentioned before, since this appears to be a first battery bank learning experience, it's not a bad idea to check what is available on the shelf at your local battery store (I use BatteriesPlus as I'm on a commercial account there)
It's often difficult to get online battery sellers to honor a warranty, or to do so you have to ship them the bad battery on your expense, as well as pay freight charges for the replacement, so shopping local will keep your system from being down any longer than necessary.