For vanlifing its impossible to only go down to 50%, I need all of that. I have 2x Leoh AGM 160ah batteries and their datasheet shows full discharge at 10.8V if I have constant 14A current load (about as much I have if i run my laptop and lights + fridge). Does not say anything on datasheet that I cannot discharge all the way to 10.8v. I try to stick to 11.5v but its hard during winter days as no sun for solar.

These quick little tech talk episodes are the best thing since pockets on a shirt. Love These!!!!!

@PacificYachtSystems

3 жыл бұрын

Thanks Tim!

Hi Jeff, thank you for answering my question, it's very much appreciated. The goal is to cycle to no less than 60% so you've answered my question, to set it at 50%(12.3v according to the datasheet). The system is for my brother, and hes not likely keep an eye on things like most people do, so I'm installing a Victron smart protect to save the battery. Again thanks again for the video 10/10. Best Regards Stormer.

@PacificYachtSystems

3 жыл бұрын

Thanks Stormer.

Thanks Jeff, I was thinking 20% but I will definitely set it higher probably 30% like you suggested 😊

@PacificYachtSystems

3 жыл бұрын

Happy to help!

Wealth of knowledge!

@PacificYachtSystems

3 жыл бұрын

Thanks Denny!

Nice video , but whats these mean in volts ...As what is 60% discharge on agm or wet flooded in volts ? Cheers

Very good information as always Jeff. Thanks to you I get questions from my fellow boaters regarding batteries and such. And I can actually give them an answer 😀 And I always tell them to subscribe to your channel. 👍

@PacificYachtSystems

3 жыл бұрын

Glad to help

Hi Jeff, Hi All, I bough 12v 95ah AGM battery to my car but there was module issues and 3-4 times my battery went to about 9.5 volt, so fully discharged/ I tried to recharge them after 4 days of staying discharged but I was wondering if my battery is damaged you think? When I go inside my car after 72 hours, it only shows around 11.9volt 12.1volt when ignotion is on. I was expecting to see 12.6-12.8 volt at least

It is my understanding that, equally (or more important) any lead-acid battery be FULLY recharged as soon as possible after being discharged, and maintained at full charge when not in active use.

@PacificYachtSystems

3 жыл бұрын

Well said.

Ok Jeff, I'm am real electrical ignorant person and this may be kinda of a dumb question. But I always hear battery discharge in percentages. But, what does percentages really mean? Like in volts? In my case a new to me sailboat, 6 100 AMP Hours AGM (new), Victron Solar (Smart) Controller, 3000 watt Inverter Charger, and the new Victron battery monitor. I found you a few years ago and watch you religiously!!! Like as soon as you post!!! I've taken your advise and have been following your advise for my boats and I am so much more confidant due to you and your business. Many "thank you's" from me. Ken

@PacificYachtSystems

3 жыл бұрын

Hi Ken, great question. Battery voltage and how it refers to battery capacity is very similar to how heart rate relates to health. Battery voltage is only a good indication of capacity if the battery at rest (i.e. no charge or discharge for 24 hours). Similar to how a resting heart rate is a good indication of your health. How often is house battery not used or charged for 24 hours, almost never if onboard and using the boat, hence battery voltage is always taken in context to loads or charging happening at any given moment. Similarly, what physical exertion you are doing will affect our heart rate, and if we are running up the stairs or alternatively sitting will affect heart rate differently. Therefore voltage like heart rate all depends on context and is therefore hard to quantify capacity.

@pietkun007

2 жыл бұрын

@@PacificYachtSystems hance my question in another thread. What is 50% at let's say 700w. I'm sure it won't be 12.2V under load. What should i set my controller to at that load. 11.8V or even less?

Jeff, great info on standard AGM batteries. I just installed 3 Firefly #31 on our boat. Based on my research they can be deeper discharged without issues. Is that true.

@PacificYachtSystems

3 жыл бұрын

Yep, you can regularly discharge to 20% of capacity and still have over a thousand cycles.

I have a vmax battery 135amp. I only use it on a 46lb thrust trolly motor. After 2-3 hours my voltage meter reads 11.8 with a load . When I turn it off the battery comes back up to 12.2 is this normal and you say 11.8 is okay right 👍

@PacificYachtSystems

3 жыл бұрын

My suggestion, based on your application, would be to not go any lower then 11.8 volts under load.

Hi Jeff why are there two sets of battery terminals? 2 large lugs positive and negative and two small studs with nuts. would it be better to have my starting circuit on the large lugs for my starting battery?

@borysnijinski331

3 жыл бұрын

Large lugs for high current. Small lugs for voltage monitoring connections?

@PacificYachtSystems

3 жыл бұрын

It's not uncommon for batteries to offer a marine terminal and an automotive terminal on batteries, makes it easier to interconnect existing cables with specialized ends already crimped on the cable ends.

Hello is it safe to keep AGM batteries in the same room as your sleeping do they give off gases that would harm me

@elmerwaltermeyer8340

5 ай бұрын

No they won't harm you

Is it true that the AGM battery needs to be charged above 14.2 volts to be fully charged?.

@PacificYachtSystems

2 жыл бұрын

Good battery brands will list the charge voltage right on the battery, or in a manual. Most AGM's want 14.4v to 14.6v for bulk / absorb charging. Note they need that voltage for hours to fully charge. Just getting them up to that voltage is nowhere near full yet.

@owenbruce4120

7 ай бұрын

Yes, some manufacturer's recommend 14.8 or 15.0 volts on 200+ amp batteries

How are these percentages measured? What voltage drop equates to 50% discharge?

@PacificYachtSystems

3 жыл бұрын

For a 12 volt lead acid battery at 50% with no loads or charging for 24 hrs will be at 12.2 VDC.

@pietkun007

2 жыл бұрын

@@PacificYachtSystems I don't realy agree. 12.2V would be under no load but cut off time should be calculated under load meaning for example 300W , 600W or 1000W. Your measurements under load when setting up the controller will be totally different and way lower than 12 at 50% butter (when load is discovered will show 12.2). Can you please provide the way of estimating this or calculations needed to be made. We also know the load is only temporary and it can fluctuate. Cut off time for 50% of a 12V battery under load is definitely lower then 12.2V and some controllers don't even allow you to set it abowe then 12V threshold.

💯

@PacificYachtSystems

3 жыл бұрын

Thanks Javier.

The best thing I ever did on my boat was get rid of the AGM's and replace them with a DIY lithium (lifepo4) my AGM's weighed 146 kg for a total of use able 268ah (@ 50% DOD), my 500ah lifepo4 weighs 60kg (400ah use able @ 80% DOD) a weight saving of 86kg (more room for beer)

@PacificYachtSystems

3 жыл бұрын

Thanks for sharing, tell us more of your Lithium DIY setup.

@dannywelbz3650

Жыл бұрын

The price is insane

@cenchloraadums3143

8 ай бұрын

​@@dannywelbz3650not if you do the math right. LiFePO4 s can do 100% DOD @ 1C and still can last over 2000 cycles.

20% 30% 50%… of what. What voltage reading. My new agm batteries went to from 12.9 to 13.2 volts after plugging them into shore power for a day. After being plugged into a power pole for a week… they read between 12.2 and 12.6.

@PacificYachtSystems

2 жыл бұрын

Hi Samuel, for a 12 volt lead acid battery, including AGM, 50% of battery capacity should be 12.2 Volts after 24 hrs of no charge or discharge at 77 degrees Fahrenheit. A voltage about 12.8 is a charging voltage, with most float charging at 13.2 - 13.6 depending on battery specs.

Jeff, have you done any load testing of batteries? I found this video kzread.info/dash/bejne/m61nysmaj7Obibw.html really interesting. They tested AGM and FLA batteries and found that they didn't come anywhere near the capacity claimed by the manufacturer even under best case usage. They didn't reveal brand names, but the tested multiple brands and found they were all "optimistic" if we're being generous or "fraudulent" if we're being more cynical.

@PacificYachtSystems

3 жыл бұрын

Hmmm, interesting. Personally always de-rate the published number by about 10-20%, For instance a 220 amp-hour battery is instead 200 amp-hour. Like too many things, there's marketing and then reality.

@youtubeuser1052

3 жыл бұрын

@@PacificYachtSystems That is probably a good idea, but if you look at the manufacturer data sheets (and assuming the manufacturer's data sheets are honest and accurate) you can get an idea of how much extra life you can expect for a specific amount of derating. But the interesting thing in that video was that under load test the lithium batteries exceeded the specs published on the data sheet but all of the lead acid batteries fell short of what the data sheet claimed. But the tests were performed by a KZreadr using test equipment provided by a lithium battery manufacturer. Presumably that manufacturer knew that their data sheets are conservative while lead acid data sheets are optimistic. It would be interesting to see tests performed without any battery manufacturer involved at all and see if it's consistent across brands that lithium data sheets tend to understate capacity and lead acid data sheets tend to overstate capacity.