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gzimmerman372 03-01-2019 09:58 AM

AIMS 2500 Inverter/Charger
Does anyone here have an AIMS Power Inverter/Charger? I just ordered mine and it came in today and I'm kind of confused about how to set up the charging part. The little turn knob labeled Charge Current Control, how are you supposed to figure out what to set it at? 0-100%, 100% being the 105 amps its labeled for, I assume?

New says not to install in a compartment with batteries or equipment requiring ignition...I assume batteries are safe as they want the inverter as close as possible to the batteries to eliminate drop. But for the ignition, does anyone have theirs in a closet type space with their tankless water heater? Current plan would have them about 4 feet apart. Thinking about possibly 2 small exhaust type fans in the roof to help pull any fumes out?

MarkyDee 03-01-2019 03:03 PM

Batteries should be in a vented battery box to eliminate flame or explosion hazard. Maybe include the AIMS in its own vented box to segment it from other things?

As for where that little knob should be set, I don't know. Usually set your charge current to C/4 or C/5, and float at C/10 to C/12. A 105A max charge current would only be set for a battery (or set of parallel batteries) with a capacity of 420 to 525 Amp-hours.

(C is the capacity of the battery in Amp-hours....)

gzimmerman372 03-01-2019 03:16 PM

Thanks! So the batteries just on the floor would not be a good idea? Wouldn't them being vented still open the same risk? Or would the wood of the boxes help defuse the "fumes" and any arc/sparks warned on the inverter from meeting each other, for lack of a better phrase.

I will have 3 batteries, 12v @ 155aH each. So total will be 465aH. That would put it at 93 - 116 ah at your suggested rate.

MarkyDee 03-01-2019 03:37 PM

Well, depends on what "floor" they're on. If its the floor of your bus, no, that's not a particularly good place.

Think about it this way - batteries contain sulfuric acid and they can emit hydrogen gas under certain circumstances. Should a battery explode (and I've had one explode), where is that sulfuric acid gonna land? Also, if the battery vents hydrogen gas, will that gas be at a sufficient strength to ignite and will it find an ignition source (open flame, spark, etc.)?

A proper battery box will contain the sulfuric acid in a leak/explosion, and it can vent the hydrogen gas to the outside atmosphere in a safe way.

(Note that a battery isn't a bomb. If it explodes its not going off like a hand grenade, throwing shrapnel everywhere - its usually just enough of a "pop" to split the case open and allow the contents to leak with a bit of splatter.)

Usually a battery box is made of a plastic or fiberglass that is resistant or impervious to acid. It usually has two vents - an intake and an exhaust. You put the fan on the intake so that the box is at a slightly higher pressure than "atmosphere" so that if the batteries vent, the hydrogen gas goes out the exhaust and doesn't pass the fan. If the hydrogen gas passes a DC fan, and that fan is of the "brushed" type, then that fan produces sparks by its nature and can set off the hydrogen gas. This also goes for the sulfuric acid because the acid can also atomize and you don't want it going past the fan.

And all of this isn't even touching the idea that hydrogen gas and sulfuric gas is not something you want to be breathing....

gzimmerman372 03-01-2019 06:40 PM

That makes a lot more sense. I'll build a box for both the batteries and inverter separately. I think with those being contained and vented outside the water heater should be safe.

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