The BMV 712 was flawless on my lithium when the capacity was known & the li specific settings were in the ballpark, its a true calculator. I would feel safe using that monitor in the middle of knowhere, one glance & you trust it's SOC level. Great thing is a capacity test for me is done in the field with a high powered drain plug so every year or so I can quickly chk true capacity. By the looks a true control load test is only 1-2% more accurate & not worth it for lithium.
Also some of these dropins have a very accurate bluetooth SOC gauge they must have a good smarts inside them. But not as trusty as the victron.
The thing is you can get by with volatage & current alone, but that gets you 10-20% ballpark, to get 5-8% is far more work than a basic capacity test so it's pointless, just go a good amphour counter monitor. Also predicting the SOC on voltage is next to useless for solar as li absorbs so well you just can't say "ok thats 90%" like you can with a solid source of power.
I did try the Balmar SG200 for a few months but the thing had glicthes (soc would change by itself after resting etc), dunno if these have been fixed but their support was a joke, they basically said "yeah we dunno why that is happening" The cruisersforum thread is also full of uselessness so I gave up & what I found was the thing MUST have the correct capacity entered or else it's quite off the mark. imo it's just a calculator with BS self learning unproven crap. Since it takes 30secs to configure the BMV on th ephone & the SG200 needs a capacity test it's useless to me. HOWEVER, it has a gourgous screen unlike the 1980s style BMV need to squint your eyes just to read it display.
The hope was that this was a set & forget monitor for Lead acid, but it's BS, as it actually takes many many cycles to learn & give anykind of SOH calc. by that time you could have done a handful of 25Hr discharge tests. In fact for flooded lead acid a 5dollar volt meter, 15dollar hydrometer is all you need. This SOH is a complete load of marketing rubbish, I work with a know lifespan, so golfcart batteries are commonly said to last 4-6yrs fullime, 8-10yrs part time, so those are my replacment times. You would have to be mad to trust a SOH calculation before a big trip, might as well ask a psychic.
Also some of these dropins have a very accurate bluetooth SOC gauge they must have a good smarts inside them. But not as trusty as the victron.
The thing is you can get by with volatage & current alone, but that gets you 10-20% ballpark, to get 5-8% is far more work than a basic capacity test so it's pointless, just go a good amphour counter monitor. Also predicting the SOC on voltage is next to useless for solar as li absorbs so well you just can't say "ok thats 90%" like you can with a solid source of power.
I did try the Balmar SG200 for a few months but the thing had glicthes (soc would change by itself after resting etc), dunno if these have been fixed but their support was a joke, they basically said "yeah we dunno why that is happening" The cruisersforum thread is also full of uselessness so I gave up & what I found was the thing MUST have the correct capacity entered or else it's quite off the mark. imo it's just a calculator with BS self learning unproven crap. Since it takes 30secs to configure the BMV on th ephone & the SG200 needs a capacity test it's useless to me. HOWEVER, it has a gourgous screen unlike the 1980s style BMV need to squint your eyes just to read it display.
The hope was that this was a set & forget monitor for Lead acid, but it's BS, as it actually takes many many cycles to learn & give anykind of SOH calc. by that time you could have done a handful of 25Hr discharge tests. In fact for flooded lead acid a 5dollar volt meter, 15dollar hydrometer is all you need. This SOH is a complete load of marketing rubbish, I work with a know lifespan, so golfcart batteries are commonly said to last 4-6yrs fullime, 8-10yrs part time, so those are my replacment times. You would have to be mad to trust a SOH calculation before a big trip, might as well ask a psychic.
