gonediving
New Member
Other batteries, away from the boat are measuring expected values eg 12vdc, 0vac
Lifepo4 cells producing AC voltage
- Thread starter gonediving
- Start date
gonediving
New Member
3 different meters were manual set to read vac. All display screens showed vac being measured
gonediving
New Member
Also strange that vac measured is approx twice the vdc. Eg a 3.3v cell is showing 6.5vac. where is the extra voltage coming from let alone that it's vac not vdc??
Q-Dog
¯\_(ツ)_/¯
Set the meter to VDC, not VAC.
gonediving
New Member
When meters are set to vdc we get expected readings eg 53/3.3vdc. when measuring AC we get the ripple
sunshine_eggo
Happy Breffast!
I wish people would use measurement equipment properly. This happens often enough:
diysolarforum.com
If you put an AC voltmeter on a DC source, you get a bad reading. PERIOD.
Google this. You'll find many examples of this where you see roughly 2X the DC value.
Jeez.
Induced AC on LiFePO4 Battery Sungrow SH5K Solar Hybrid
Hi all, I have a first generation Sungrow SH5K inverter - First generation meaning no firmware updates and limited functionality. it's almost 8 years old, so it has been a reliable system. I originally had it running a 48V lead acid battery, but now have a DIY LiFePO4 using Voltax 302Ah cells...
diysolarforum.com
If you put an AC voltmeter on a DC source, you get a bad reading. PERIOD.
Google this. You'll find many examples of this where you see roughly 2X the DC value.
Jeez.
Last edited by a moderator:
Q-Dog
¯\_(ツ)_/¯
That's why you use VDC to measure DC voltage.
ksmithaz1
Solar / EV Junkie
DMM's can be very sensitive. You can read AC voltage from almost anything.
littleharbor2
Solar Addict
2 banks in parallel. Easy peasy.
ksmithaz1
Solar / EV Junkie
3-phase for extra power, 3 AC batteries in a WYE configuration.2 banks in parallel. Easy peasy.
Ampster
Renewable Energy Hobbyist
No, the meter was set to VAC, and as noted by me and others, that will result in a faulty ready that to does not mean there is AC.
Not strange at all for a meter set to VAC when measuring DC off a pure DC source.
ksmithaz1
Solar / EV Junkie
Absolutely! Make sure you drink plenty of fluids, you will need a buck converter, and infinite patience!
MidwestBest
Redneck Engineer
Everyone is wrong! it is possible. he has just discovered a 100% efficient inverter. next thing you know the gov will be knocking at your door to confiscate you equipment and your will mysteriously disappear, nice knowing you.
Tulex
Solar Wizard
So I have 3 batteries. Does this mean I have 3 phase?
DougfromdaUP
Solar Enthusiast
What kind of meters display twice the dc voltage on ac range? My old fluke will let you read an ac voltage with a big dc offset properly, or let you check ripple on a power supply.
ksmithaz1
Solar / EV Junkie
There are valid reasons to purchase an expensive DMM.
Sergio95050
SE SW digger
MacGyver
New Member
Put a 10 Uf 100 v capacitor in series with the DVM + lead it will block the dc voltage and you can read any AC voltage on the AC setting across the battery. If you put the meter on DC it will read 0 Vdc unless the capacitor is backward or leaking.
sunshine_eggo
Happy Breffast!
Excuse me? 30 euro sounds dang spendy. Must be the VAT. Got lots of < $10 meters that work nearly as well as my Fluke (for my uses) AFTER I've calibrated voltage with reference and the adjustment pots.
Though when there's ANY question in accuracy, the Fluke comes out to check sanity.
Yep, the fluke sits in the cupboard when I need it for calibration etc. Otherwise, a cheap multimeter that I don't mind dropping/getting liquids on/stepping onto/throwing around/...
sunshine_eggo
Happy Breffast!
My goto is the somewhat spendy Klein Tools CL800, but that's mostly because of features (clamp DC ammeter). Aw... who am I kidding... I'm lazy. I use the first one I encounter. There are usually at least 3 in any given room with me.
OzSolar
Whatever you did, that's what you planned.
Or stolen from a jobsite.
My Fluke 87 grew some legs on a jobsite several years ago. It was in my service body truck which I normally leave unlocked after I get to a job site.
Replaced it with several $30 "Kaiweets" etc. types from Amazon and was happy with them for years. Only just recently got a 233, the one with the remote wireless display, and a 115 and that was because my employer pays for my tools.
When I got my next service truck, I ordered it with power locks on the tool boxes tied to the truck keyless entry. Surprisingly it wasn't that expensive.
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