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Battery Monitors - Part Deux


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#1 bigal.nz

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Posted 12 September 2019 - 11:36 AM

So after a lot of reading articles like this : https://marinehowto....attery-monitor/ (which is great by the way) who does any of the following:

 

1. Who here has taken the time to measure actual Capacity? 

2. Who thinks that there bank is being kept full by solar?

3. Who has the actual Peukert factory for there monitor?

4. If on a mooring do you regularly ensure full SoC is reached by using a workshop charger?

5. What percentage of Ah do you use for tail current to determine charged - finish float cycle? (I know this is sometimes a published spec - but Rod Collins deviates from this)

 

Very interested in anyone here who has calculated actual capacity. Short of buying a expensive meter, would require a bit of setup of a light bulb, variable resister, a multi meter I think at the very least to get a ballpark figure.

 

My calculations were that if you had a 180Ah bank and took out 40Ah you have gone to 77% SoC.

If you didn't realize your actual capacity was 160Ah and took out that same 40Ah you have gone to 66% SoC. 

11% different which is quite a lot.

 

Cheers

 

Al


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#2 Island Time

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Posted 12 September 2019 - 05:42 PM

1. Who here has taken the time to measure actual Capacity?  Me, I usually do this when supplying new banks, and a test when batts are suspect.

2. Who thinks that there bank is being kept full by solar? Sometimes, depending on controller

3. Who has the actual Peukert factory for there monitor? Monitors don't have peukerts factors, batts do. Hardly anyone does this - but they should.

4. If on a mooring do you regularly ensure full SoC is reached by using a workshop charger? No

5. What percentage of Ah do you use for tail current to determine charged - finish float cycle? (I know this is sometimes a published spec - but Rod Collins deviates from this) 1-2 %

 

Welcome to the real world. Virtually no-one actually knows what there battery capacity IS, not whats on the label. Close is all you ever get.

 

My discharge test is a home made rig, an old analogue electric clock, and an inverter that switches off at 10.5v (flat). Its not exact, but neither is it far out. 


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#3 bigal.nz

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Posted Yesterday, 09:28 PM

Nobody else jumping in - maybe they all leave it on factory defaults.

 

Anyway I have programmed my Balmar per Rod Collins instructions and have the exact Batt specs from East Penn. Learnt a lot in the process and spent a few $$ on upgrades to other parts of the charging system  ;-) - today the Batteries were being kept in float by solar at 13.5 which is what East Penn recommend for float. 

 

Looking to add a Pi running Venus OS now so I can monitor the lot from home. Not an issue OFC if your boat is sitting off your balcony!!!


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#4 lateral

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Posted Yesterday, 10:26 PM

So after a lot of reading articles like this : https://marinehowto....attery-monitor/ (which is great by the way) who does any of the following:

 

1. Who here has taken the time to measure actual Capacity? Seriously considered it, but too many more important things to do.

2. Who thinks that there bank is being kept full by solar?  Solar is still on to-do, hence above.

3. Who has the actual Peukert factory for there monitor?  Forgot to ask Endurant when I called them. So 1.3 factory default for FLA.

4. If on a mooring do you regularly ensure full SoC is reached by using a workshop charger? No, but get  1% TC 3-4 times per year & equalise twice..

5. What percentage of Ah do you use for tail current to determine charged - finish float cycle? (I know this is sometimes a published spec - but Rod Collins deviates from this)

I reckon mine is 0.5% but set it at 1% on monitor. Not that it makes much difference as it doesn't terminate charging. Something like <0.1v drop /hr. I've ceased being obsessed with

where 100% actually is as it looks like my FLA's will last the distance even with my PSOCing them.

The calibration of the Balmar SG200 is another matter. Like, when was it acceptable to market something that only "sort of works". (For FLA's anyway)

 

Very interested in anyone here who has calculated actual capacity. Short of buying a expensive meter, would require a bit of setup of a light bulb, variable resister, a multi meter I think at the very least to get a ballpark figure. If I get  FireFly carbon foam batteries, I will capacity test them once I've done a couple of cycles with similar.

Family has a container coming from the US later this year which would be ideal, but  can't get excited about switching.

 

My calculations were that if you had a 180Ah bank and took out 40Ah you have gone to 77% SoC.

If you didn't realize your actual capacity was 160Ah and took out that same 40Ah you have gone to 66% SoC. 

11% different which is quite a lot. Yes

 

As an aside.

My start battery, SLA, was on daughters fizz boat for 2yrs. Then left for 2ys  to go flat and then put in as start.

Is still going strong at 8yrs. It is charged by ACR with my house bats which are 4yro.

Yeah, I know, I shouldn't be mixing types on same charging parameters. Disconnect on equalize.

 

 

 

 


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#5 wheels

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Posted Today, 05:00 AM

When you start reading the nitty gritty type info available re charging of LA batteries, you quickly realise how complex. Very expensive banks which have long lasting life expectancy, require extra special care if you want to achieve that potential life time from them. Which of course, equates to $/Ahr achieved.
However, it is also very easy to become over nerdy about it all as well. I remember many years back, talking to a friend about battery care. After going through all the technical aspects of the discussion and explaining why my charging system was so flash and how he needed a better monitor and charger etc, he kind of flawed me with the reply, well my House Batt is just a plain old starting battery and it is 10yrs old now and I do nothing special to it. I start the engine when we need the fridge brought down and that's about it. (they lived aboard by the way). Well that blew my nerdy argument right out of the water. OK, so I am not saying that proper care is not needed. Just that sometimes we can also go overboard as well. Sometimes factory specs are all that is needed and some chargers don't allow that much detail in altering charge parameters. So if you can't or don't know how, don't fret.
In regards to the original post above, do remember that capacity is also linked to age/discharge cycles. The older and more use a battery gets, the less capacity the Batt has and the calculation needs to be regularly altered (say once per yr) to compensate.


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#6 Fish

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Posted Today, 10:58 AM

When you start reading the nitty gritty type info available re charging of LA batteries, you quickly realise how complex. Very expensive banks which have long lasting life expectancy, require extra special care if you want to achieve that potential life time from them. Which of course, equates to $/Ahr achieved.
 

I was recounted a story yesterday about a guy who spent something like $5k on flash ladeda lithium something batteries. They died within a year. Upon taking them back to the retailer, he was advised that there was some detail in the charging that he was doing wrong, and they wouldn't replace his batteries. Apparently this type of lithium ladeda had a slightly different charging requirement to every other lithium ladeda.

Anyway, the guy was out of pocket enough to really put you in a bad mood...

Hence why I still go for the cheapest option, being FLA. The downside risk is reduced greatly when you outlay $600, instead of $6,000 for a battery system.

My last lot of FLA house batts lasted 10 yrs. But they only need to last 1 yr to match the outlay of the latest and greatest...


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#7 bigal.nz

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Posted Today, 01:00 PM

Yes good point. That's why I have decided I will only ever buy batteries from manufacturers who publish full specs.

I had reason to question my setup as I dropped a cell.
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