Renogy Battery Monitor vs Trimetric UPDATE- Camping Test

[BFL13]

Updates-12 May 22, 19 May

Somebody mentioned one of these recently, can't remember who, sorry.

Anyway I ordered one thinking it would work much like my Trimetric 2025 (the R's manual seems to show it will) so I can use it in the TC instead of swapping the Trimetric out of the Class C every time. The R is a lot cheaper than the Tri was if they even still make those.

I see the reviews in their link, but any ideas from folks here on how this R gizmo might do compared with the trusty Tri I have had for years?

https://ca.renogy.com/500a-battery-monitor-with-shunt/

[Microlite_Mike]

LittleBill wrote:
i have the renogy (well a variant of it), biggest issue I have is the percent full, its simply based on voltage, not amperage. so if you have it set to 14.4 and your charger is still putting 20+ amps into it, the meter shows 100% full. That's my only issue with it.

This is where the Victron units excel. 100% SOC is reset based on 'Tail Current', not voltage.

Victron also incorporates the Peukert Factor into their calculations which is extremely important if monitoring Lead Acid batteries with loads that vary from just a few amps (lights) to heavier loads of the furnace, etc. Then there are the extreme loads becoming more prevalent today in RV's like 12volt refrigerators or residential refrigerators running off an Inverter or even a Microwave causing a draw from batteries in the range of 100-150 amp.

Unless the monitor takes into effect the varying loads (or varying charging currents) any SOC indication is at best a wild guess.

Only exception to the Peukert effect with varying high/low current draw is a LiFePo4 battery which has essentially a Peukert Factor of "1.0".

Peukert's Law

[BFL13]

Read the manual it is not too clear but seems you have to use it their way. Have to see it working before I can understand some of the points raised in the replies above

Thanks all

[folivier]

I like the Victron BMV-712 also since it has bluetooth and you can adjust it and see everything on your phone or MacBook. Their Smart Shunt is the same thing without the gauge, great value if all you want is a bluetooth unit.

[LittleBill]

BFL13 wrote:
Does the AH counter not work right to say how many amps down or back up it is wrt zero ( as zero was at the last reset) ?

Ah counter works fine, and is accurate, but the larger 100% is deceiving, which appears to be based on voltage alone. there is no setting for amperage. only ah high and low voltage. should have been trivial to add it in, but its a miss.

[BFL13]

Does the AH counter not work right to say how many amps down or back up it is wrt zero ( as zero was at the last reset) ?

[LittleBill]

i have the renogy (well a variant of it), biggest issue I have is the percent full, its simply based on voltage, not amperage. so if you have it set to 14.4 and your charger is still putting 20+ amps into it, the meter shows 100% full. That's my only issue with it.

[pianotuna]

Hi,

I'd use Victron as it is both cheaper and better than the trimetric.

[BFL13]

I will watch for that, thanks.

I never did set up the Tri like it says, since I don't like the way they or the other brands that do percent SOC do that. Capacity is a big variable with temperature, so IMO the percentage SOC reading is probably wrong.

I just get the straight volts, amps, and AH readings and do my own SOC calculation based on my own idea of battery capacity when full, which depends on battery age and temperature which I allow for.

I note the morning voltage before solar kicks in and when the furnace is not on for a low load voltage (not quite resting of course) and the table for voltage/SOC for that battery (same as before getting a monitor), and compare that with the AHs down showing on the Tri from last full (my AH est of full). Makes for a good cross-check of approx SOC--close enough for me.

If the morning voltage says it is 50% SOC (12.1v with a Trojan eg) and the AH count is 215 down, then that makes 100% 430AH. I note whether that is reasonable for the temperature and age of batts.

So I hope I can do that with the linked Renogy monitor but not clear from a quick look at the manual if I can ignore all the settings and just use it as a straight AH counter plus as a voltmeter and ammeter same as the Tri. And I hope it has a manual AH counter reset to zero!! it better.
The Tri lets you pick that or use an auto reset--which is no good for when on solar, eg so you disable auto reset.

Anybody know about how the R is for all that? I will find out eventually, but be good to know what to expect.

[Microlite_Mike]

The Trimetric does a far better job than the Renogy monitor. That said, I prefer the Victron units, either BMV-712 or "Smart Shunt".

If you absolutely need to know the exact amount of battery capacity remaining, Renogy unit won't do it. Close, maybe, but no real cigar as it uses too many 'general assumptions' in the algorhythm that calculates SOC/DOD.

It's probably OK if one is only drawing a SMALL amount of current that remains steady. Varying high and low draws, for example a furnace cycling on and off over the night, can yield noticeable errors which the Renogy unit just "excuses" when the battery is fully charged again and the monitor resets to 100%

[Matt_Colie]

BFL,

I also have a 15~20yo 2025, but I was looking at Bogart the other day and they have an new model with new tricks....

Matt