battery capacity.
- Thread starter sparkyv
- Start date
sunshine_eggo
Happy Breffast!
Yes, but that device must be synchronized to the battery at some point prior to the operation.
If you're looking for a device that can magically read a battery/cell state of charged based on a momentary measurement during a charge/discharge, there no such beast.
OffGridInTheCity
Solar Wizard
It depends on the battery type whether voltage can be a guide. LifePo4 - not so much because the voltage range is sooooo flat thru most of the DOD. Lithium-ion - more so because the 100% to 0% voltage range is so much larger than LifePo4. But when I say 'guide' I mean that at best, it's a fuzzy metric.
A shunt and meter is typically used to count amps in and out. So you zero it out at empty or full and it counts amps to tell you if you're full or empty, or somewhere in between.
Victron has a nice setup, as does midnight solar, looks like Spartan Power has one too. A cheap option is Junctec meter - I dropped for one and it's surprisingly accurate and reliable so far.
Here's the app display for it:
Victron has a nice setup, as does midnight solar, looks like Spartan Power has one too. A cheap option is Junctec meter - I dropped for one and it's surprisingly accurate and reliable so far.
Here's the app display for it:
sunshine_eggo
Happy Breffast!
Hydrometer is only roughly accurate. There is always a lag between changes in SoC and SG. I've seen at least two major manufacturers recommend sitting at float for 2 hours before checking SG.
Thanks for your response, I couldn't find "junctec". Is that display for the victron phone app?A shunt and meter is typically used to count amps in and out. So you zero it out at empty or full and it counts amps to tell you if you're full or empty, or somewhere in between.
Victron has a nice setup, as does midnight solar, looks like Spartan Power has one too. A cheap option is Junctec meter - I dropped for one and it's surprisingly accurate and reliable so far.
Here's the app display for it:
It's Junctek. It has nothing to do with Victron. It's just another brand of battery monitor.
It's the knock-off version of a victron. LOL Yeah, sorry it has a 'k' not a 'c'.
The forum deleted the vendors - we had a lot of data there.
The vendor had a intro/forum discount(40% off?), but you could PM him for one - @kang lee
Found them on aliexpress:
junctek battery monitor - Buy junctek battery monitor with free shipping on AliExpress
Quality junctek battery monitor with free worldwide shipping on AliExpress
www.aliexpress.com
Took about a month to arrive. I was skeptical, but it was easy to install and works really well. Choose a 100A, 400A, or 600A shunt.
You don't need the display, you can just use the BT link with a smartphone. I like the display for a quick visual on battery state:
thank you. I'll check it outIt's the knock-off version of a victron. LOL Yeah, sorry it has a 'k' not a 'c'.
The forum deleted the vendors - we had a lot of data there.
The vendor had a intro/forum discount(40% off?), but you could PM him for one - @kang lee
Found them on aliexpress:
junctek battery monitor - Buy junctek battery monitor with free shipping on AliExpress
Quality junctek battery monitor with free worldwide shipping on AliExpress
Took about a month to arrive. I was skeptical, but it was easy to install and works really well. Choose a 100A, 400A, or 600A shunt.
You don't need the display, you can just use the BT link with a smartphone. I like the display for a quick visual on battery state:
what is SG ?
ok, so not applicable for lithium.
sunshine_eggo
Happy Breffast!
Post#5 was an attempt to clarify.
The problem with trying to measure SOC by voltage on lifepo4 is the charge and discharge voltages remains nearly constant until either end.
From 90% to 20% is nearly constant:
And it's level varies with current. The chart above is only for a given current. More current shifts it down. Less current shifts it up.
