Charging our battery bank with a generator through the AIMS inverter charger

SteuandMichelle

New to this forum, and grateful for any help. We've been running off-grid with solar/battery/inverter system for about 3 months. So far we've had more than enough power for our needs, but sunlight will be scarce this winter and we'll need to charge our battery bank with a generator. I'm looking for some basic instructions on how to do that. Here's a rundown of our system:

- AIMS Inverter-charger 3000W
- (8) 200 AH batteries
- (8) 300 W panels
- Midnite charger controller 150
(+ necessary breakers etc.)

a 2400 watt, 24 volt system. 

We have a 3800 running watt generator, and would prefer to try to make that work if possible. The generator doesn't have the auto-start, and we're willing to run it manually every time we need to charge the battery bank. I'm hoping someone can give me the step-by-step instructions for how to actually charge using the generator: what cord(s) do I need, how long will it need to run approx. , etc.

Let me know if I need to give more info...

MichaelK

Here's the link to that AIMS unit.  See page 8
http://www.aimscorp.net/documents/PICOGLF30W24V120VR.pdf

I personally will never, ever have a auto-start generator, after the experience I had with the fuel line of my generator vibrating off after starting it.  Watching a stream of gasoline pouring onto the running engine was a real attention getter!

Estragon

Off-grid, it makes generally makes sense to use the generator for charging in the bulk stage only, and let whatever solar power there is finish to the extent possible.

For example, say the bank is down to 50% state of charge. Assuming 400ah@24v, that's 200ah. The 400ah bank, assuming flooded lead acid, will take a bulk current of ~60a@29v, or ~1700w. The generator should be able to handle that (unless the charger has a very poor power factor - some do).

You would fire up the generator early in the morning to charge the bank from 50% to around 80%, so about 120ah of the 200ah deficit. At 60a charging, that should take a couple hours of generator run time. Unless it's really gloomy or you have high daytime loads, you should get at least some additional charging during the day.

You don't need to get to 100% every day. The objective is to get above 80-85% most days, and fully charged at least weekly or so.

I also wouldn't use AGS for the same reason as @MichaelK - too many things to go wrong.