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/

[RV_Ken1972]

Matt_Colie wrote:
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

Turns out that one of the Trimetric's tricks is terminating charging based on the amp-hrs sent back to the battery. This supposedly makes sure that the reverse reaction is complete, with no lead sulfate left. There's an article on their applications page that describes better than I can.

[BFL13]

I thought the Renogy monitor's "battery attenuation ratio" was just fractured English and might mean charging efficiency, but for fun I Googled the term and it is real!

Renogy: ("Battery Attenuation Ratio: After the battery Capacity cumulatively once per cycle, The capacity value is automatically changed according to this ratio.")

(I saw where they use "machine translation" )

Unfortunately the articles I read on that made no sense to me even when written in English.

"Attenuation" apparently just means losing capacity from rated full even when doing a discharge. The Ratio idea might be Peukert or maybe how many cycles before it is down to 80% as for LFPs--??? All very confusing.

My plan is to leave that setting alone and hope nothing bad happens 🙂

Charging Efficiency is related to internal resistance of the battery. This varies among battery types and SOC when being charged and discharged and by what rate of charging or discharging.

Best plan for monitoring would be to recharge to full as often as possible and get the monitor to say the batts are full at that time. "reset" or "synch"

If you are off-grid and never manage to get your batts full for a long time, but just have them go down and up then the monitor will go out of whack. Just have to be aware of that and do the morning voltage cross check as mentioned before. Eventually the voltage version of SOC will be your only guide and not the monitor's version of SOC

[MrWizard]

BLF
My battery status monitor work's very similar to yours,, except i can't find a function for recharge compensation percentage, it has number of function values that seem to have no effect on the displayed values and operation, all designated by 3 letter names, i just wait until the meter indicates the 1/2 amp per 100amphrs capacity charge rate

[3_tons]

Ha, good to know!! All I can say is I sure hope your ol’Hudson came with a heater!!

3 tons

[RLS7201]

So many do-dads to keep ya-all concerned. While snow birding, if my solar charger goes into float, then I'll have enough energy to play on the computer and watch satellite TV and then make it through the cold night with the furnace running. When I wake up in the morning I make sure every thing is shut down and check the voltage meter. Normally I see 12.3-12.4 volts and a new day starts.......

Richard

[3_tons]

If the battery is known to be fully charged, then you apply a known, timed load such as a halogen shop lamp on it, I would think that would be a good wattage reference point to begin a measured recharge…While maybe not 100% precise, this might be a fair enough exercise (with a little arithmetic 🙂 ) to arrive at charge efficiency (a kinda power out vs power in thingy…).

3 tons

[BFL13]

If the monitor has a built-in allowance for heat loss while recharging like Trimetric and Victron have, the allowance needs to match the battery type.

Trimetric uses 94% while Victron uses 95% (IIRC) as default but you can program those values. LFP calls for 99%, while FLA comes out better using the defaults.

If you use a monitor set at 94% on an LFP, it is 5% out of whack for AH restored. (99-94) That is, it will show on the monitor that the LFP is not full yet when in fact it is.

With this Renogy having ( I think!) no charging efficiency set, it will think all the AHs are going to the battery, and it will say the battery is full before it is. That is what looks like happened with recharging my pair of SiO2s.

I do not know what the charging efficiency should be set at for those. They are somewhat like AGMs which do heat up. I got fairly close results with the Trimetric on AGMs so 94% might be good for the SiO2s also. Not a clue.

Doing some math, if you knew the extra AH it took to get them full after the monitor said they were, you could get the percentage for heat loss.

In this case, I did not see when the monitor reached 200AH/100%. It was already there showing 14.6v and 5.xx amps. 5 hours later it was showing 14.7v (charger setting) and 1.xx amps and I dropped to 13.4v for overnight.

So lets pretend it ran over for 6 hours at median/average whatever of 2 amps --that is 12 AH. I had been down as low as 50% SOC so took 100AH restored to full. So the charger really did 112AH to do 100AH-- EXCEPT that is a total WAG.

If the monitor was set to allow 6% for heat it should say 100 after 106 went in.

What if the battery acts like an AGM and really heats up near the end of recharge? The SiO2 could have been truly full earlier and a lot of that 12AH over (estimated) was heat. Don't know. I could feel my AGMs heat up when near full but I did not feel-check these for heat or use my temp gun.

The AGMs got hot at the end and charging amps began to rise again. Oops that was not good and time to turn off the charger!

Anyway, more observations needed. Meanwhile I don't know how to set the charging efficiency allowance on this Renogy Monitor anyway. (If it can be). You don't need that value for discharging; it only matters for recharging.

The way it is now, after some time camping with the AH going down and then back up with any charging, it will show the AH as being higher than it really is and with that show the % full to be higher.

That is where the "morning voltage" comparison for SOC comes in--using the battery's spec table for resting voltage/SOC. Just note the voltage reading is loaded voltage by a little ( you can see the amps load on the monitor). After a while, the voltage version of SOC will be lower than what the monitor AH reading says for SOC.

So you can still tell where you are at if you need to know it that accurately. In real life all you want to know is whether you can go another day before recharging the batts or whether you have to do that today.

[3_tons]

BLF, After about 11 yrs of very accurate SOC measurements from two GC’s using a Xantrex LinkLite, upon switching over to LFP’s, no matter what settings I attempted (even borrowed Victron's settings!), I was never able to get the LinkLite to ‘reliably track’ SOC’s beyond about one discharge cycle - in the end, I could only conclude that it’s built-in algorithm was not suitable for a non-FLA voltage profile (I donno?)… In light of this (I don’t claim to know much about SiO2’s!!), it would be interesting to see if you’re able to work through this…(trust, been there done that!!) - Best of luck !

3 tons

[pianotuna]

Hi BFL13,

Thanks! That is the answer I hoped to hear.

[BFL13]

pianotuna wrote:
Hi BFL13,

200 amp-hours of what type of battery?

See my profile for the TC

[pianotuna]

Hi BFL13,

200 amp-hours of what type of battery?

[BFL13]

Went camping off grid in the TC and got to try out the Renogy 500A monitor for real.

To add to previous info in this thread, the AH counter reads from the set capacity (200AH for mine) and goes down showing ever lower AH like 123AH eg. AH comes back up with any charging such as from solar. Voltage shows a bit lower for loaded voltage and higher for when little load and the amps show as plus or minus. It all works great.

The percentage shows along with the AH amount which is just AH left after subtracting what was used from 200. Eg, AH showing 129AH, 12.5 volts, 65%, with 1.85a load.

Happens that resting spec voltage of 12.54v with these batts is 65% so that checks out. 129/200 = 64.5%

I have not got to the stage where I have to consider charging efficiency with these batts, so for now I am ignoring it. It is working "close enough" so far.

I decided I really like this monitor.

EDIT: at home, got it recharging on converter and monitor now says 200AH and 100%, but the batts are still accepting 5.64 amps at 14.6v. they are Truly Full when amps get down to 1 amp (1/2 an amp per 100AH) if I use regular AGM specs for that.

This means the AH restored was not as many as the monitor thinks, by some heat loss amount. Trimetric uses 94% for that on recharging AH count. If "battery attenuation" is the same thing with this Renogy there is a setting for that I can play with---if that is what it is.

Meanwhile I wait till amps get down to 1 amp on the monitor and then dial the converter back to a Float voltage such as 13.4 and the monitor would be set to 200AH/100% except it is already there, so have to see whether it counts down right next cycle.

[BFL13]

I did set capacity as 200AH and voltage as 14.7 and left the other parameters blank for now.

On recharging with the charger set to 14.7, the monitor gets to where it shows the batt reaching 14.6v and amps are down to under 1 amp and the batt picture has risen back to 200AH.

It is not up to 14.7v yet on the monitor (might be set at 14.6 on the charger, hard to tell exactly), but is where the batts are Full by specs. With the Tri, I would now reset the AH counter to Zero and drop the charger to eg 13.4 Float and walk away.

With the Renogy I have no clue (yet) so I just drop the charger to 13.4ish, but no idea if that 200 will be seen again after another down and up.

Is that battery attenuation setting for charging efficiency? Another mystery. That would affect estimated SOC if so.

[LittleBill]

BFL13 wrote:
I still have not figured out the right way to reset the AH counter once I get the batts to known Full. I would like to push whatever buttons and then drop the charger to Float voltage and walk away. The video says hit the Up button?

At the moment, I have the battery picture on the left showing 200AH as Full (but 199 as soon as I drop to Float for some reason).

Not sure how I got that to show 200 after some random button pushing. Anyway after a few up and downs it does hit 200 going up, but I would like to know how to make it do that every time I want it to--namely right after I get the batts to Full.

Thanks for any help.

you hold the ok button down to set parameters. the AH resets once it reaches high voltage, which is adjustable.