Battery monitoring (Trimetric type vs Panel mount type)

I have one like Brulaz's, only with 25 amp maximum. I find it works great. It is an amp, volt, and amp-hour meter. The other readings can be interesting but it is the amp-hour amount of charge or % of full charge displays that tell what I need to know.

There is a little problem with mine; it has only small screws to connect the wires carrying the main current. The maximum size wire I could connect is #14. Okay for me; it has never reached 10 amps in or out. Looks like the 100 amp version has a separate shunt that can handle heavy wires.

Well the Trip was still counting amps going in, still the charging when it stops counting or when the amps get low
My 'value' meter stops counting... So you have to look at the amps in
And decide if it's time to stop charging, it won't show you 20 amps over
But I know what's going on, so no problem
The main thing for me is that it does count both ways
And does show charge light for in and no charge light indicator for out
So I know what I'm using at night and how much I took out at night
A push button zero reset is the only thing extra that I desire

Yes, Trimetric won't compute Peukert and thus will be same inaccurate - under heavy loads - as $30 meter. I prefer paying more for quality products over Chinese cheap knock-offs, but in this case I don't see Tri being that much better. Could still pay more for a "real thing" if this was something more critical, like solar controller - but meter is just a meter, it won't make you a single milli-watt-hour of energy.

I wonder whether Tri or Victron have that 20% losses correction for charge going in/out, i.e. you take 100 AH out and have to put 120 AH in. This is how any battery works, they all have losses. I recall people complaining on Tri going to 100% and keeping on counting to 110-115, just like MrWiz described with his cheap meter.

In an ideal world I'd love to have an amp-hour counter that used a Hall effect sensor. Knowing how much stress I put on my system I can see myself burning out a shunt in short order.

The victron gauge does do Puekert. Best of the best is smart gauge but *ouch* on the price. The very popular trimetric does NOT do Puekert, so I see it as pricey and ineffective for someone similar to myself who uses a big inverter.

MrWizard wrote:
The error is not in reading the amps being used
The error is that the meter does not compensate for the effect heavy drain has on battery capacity
That is and added software feature programmed into more expensive dedicated Battery Meter, Instead of power meters that we 'value seekers' are buying
If you have enough battery and are using amps at near the 20 Hr rate for the bank you have , the readings will be accurate enough
But use the microwave on inverter and the affect on the battery is greater than the actual amount used

That will do the job very nicely

My dream meter would show charging amps
Volts
And count down amps used in a minus count

Every night when charging was done, example four batteries charging at 3 amps total at 14.2v, I would push one button
Count would goto zero
In the morning it would show me the amp hrs used overnight
-40 -60 etc..
Show me how many I am down , used overnight

I am using the same one (well the 200 amp shunt version)
And in the morning I look at the meter then mentally deduct the amp Hr S left from the set value example 300 left in bank from the 400 set value 100 used

But it will take 115 amp hrs charging to replace the 100 use (old batteries) and the meter will stop counting when 100 goes back in and reached the 400 set point, I look at the meter amps and the charge light and see 18 amps charging and know the batteries are not topped off,
I keep charging
When the amps get to 10 amps charge I shut off the generator and let the solar carry on
The less amp hrs used and the Less recharging needed the easier your routine will be

brulaz - that's the thread I was looking for. Thank you.

Almot & MrWizard - that's the info I was looking for as well. Thanks!

We have no large loads such as MW, toaster, etc. In fact, we don't have any 120VAC loads at all and we don't bring an inverter to run any (unless the genny is running). The largest 12VDC load would be the power awning going in or out and the next is the water pump. Everything else is low and slow.

I assume one of the true meters would give me more (and more accurate?) battery details but it seems as though the less expensive (and cheaper) ones will do just fine as I really want to be able to look at the meter and make the decision of "do I need to run the genny or not".

Sorry if I'm a pain with all my posts and questions. We've just dealt with crappy batteries for too many years on too many campers and we're now in a position to outfit our new rig with some of the right tools to make camping just that more fun and I want to have a plan forward so I can get it right and not waste money by purchasing the "wrong" item.

I've got one of these http://www.ebay.com/itm/DC-120V-100A-Voltage-Current-AH-Meter-Battery-Charge-Discharge-Bidirectional-/170483294165?hash=item27b1989fd5:g:gWUAAOSwyQtVz1vp on order.

Thanks all!

johnm1 wrote:

...

Does anyone know where this thread is? I can't find it and I'd like to do more reading about these monitors.

Thanks

Found one thread anyway. Several different monitors are linked to and discussed here:
Battery Monitors

The error is not in reading the amps being used
The error is that the meter does not compensate for the effect heavy drain has on battery capacity
That is and added software feature programmed into more expensive dedicated Battery Meter, Instead of power meters that we 'value seekers' are buying
If you have enough battery and are using amps at near the 20 Hr rate for the bank you have , the readings will be accurate enough
But use the microwave on inverter and the affect on the battery is greater than the actual amount used