Battery storage and charging

[ROBERT CROSS]

^
Really...how short?

This has been on 24/7/365 for 4-6 hrs/day for 8 years now.
Disclaimer....I only use the special Airstream water.

Bob
🇺🇸

[uncle_bob]

Originally Posted by ROBERT CROSS

^
Really...how short?

This has been on 24/7/365 for 4-6 hrs/day for 8 years now.
Disclaimer....I only use the special Airstream water.

Bob
����

Hi

When was the last time you did a calibrated load test and measured capacity? How does that data compare to the calibrated load test you ran when the batteries arrived? Without that sort of data, there's no real way to see what's going on.

Bob

[ITSNO60]

Originally Posted by uncle_bob

Hi

If you dig into data from folks who do a lot of A/B testing on this stuff. Having a battery on charge all the time shortens it's life rather than extends it ....

The gotcha is that we rarely have a group of RV's and the ability to do it this way on 20 of them another way on a different set of 20 and directly compare the actual result by capacity testing the batteries a couple years later. There are settings where folks do indeed have those sorts of setups ....

Bob

3 stage chargers I agree, 4 stage "Smart" chargers I disagree, when in storage mode no charge current flows in until needed. For those of us who use our equipment on a regular basis year round it is a good solution. I can't be disconnecting and reconnecting batteries all the time on my motorhome or my truck both of which sit for weeks at a time and have parasitic loads. Plus who wants to have to program clocks and radios every time? The 4 stage Smart chargers are a good solution for me. Even a 3 stage on a timer with regular loading of the batteries. IMHO of course.

[ROBERT CROSS]

Originally Posted by uncle_bob

Hi

When was the last time you did a calibrated load test and measured capacity? How does that data compare to the calibrated load test you ran when the batteries arrived? Without that sort of data, there's no real way to see what's going on.

Bob

MacGyver School of Engeanering battery testing....

Well, "Bertha" started 5 daze ago....When she won't crank and the SG poops, won't accept any juice the test is complete.

I'll get another 6v, hoping it will last at least 8yrs.

POI...The Burb is using the same procedure, with a 2a 12v BT...It NEEDS it 'cuz the parasitic draw will cause a no start in 2-3 weeks and it's not a DD'r. 5yrs SFSG.



Bob

[Wazbro]

Originally Posted by ITSNO60

3 stage chargers I agree, 4 stage "Smart" chargers I disagree, when in storage mode no charge current flows in until needed. For those of us who use our equipment on a regular basis year round it is a good solution. I can't be disconnecting and reconnecting batteries all the time on my motorhome or my truck both of which sit for weeks at a time and have parasitic loads. Plus who wants to have to program clocks and radios every time? The 4 stage Smart chargers are a good solution for me. Even a 3 stage on a timer with regular loading of the batteries. IMHO of course.

With many modern motorized vehicles (with OBD2 ports) if the computer looses power it looses its memory. This can cause problems with engine and transmission not running well till the computer relearns how to run them. Also may fail inspection till computer relearns.

Makes it a bit more important to not disconnect the batteries.

[rmkrum]

No comment needed from this alumnus:

[ROBERT CROSS]

Originally Posted by Wazbro

With many modern motorized vehicles (with OBD2 ports) if the computer looses power it looses its memory. This can cause problems with engine and transmission not running well till the computer relearns how to run them. Also may fail inspection till computer relearns.

Makes it a bit more important to not disconnect the batteries.

PARTLY true...it will return to the 'tune' it left the factory with, it will operate problem free.👍
It won't pass the emissions test because of no emissions history, hence no pass. Driving 30-50mi would normally reset it.
We had a driver at the GM store who did just that, so we could sticker it after repair.🚘

Bob
🇺🇸

[uncle_bob]

Originally Posted by ITSNO60

3 stage chargers I agree, 4 stage "Smart" chargers I disagree, when in storage mode no charge current flows in until needed. For those of us who use our equipment on a regular basis year round it is a good solution. I can't be disconnecting and reconnecting batteries all the time on my motorhome or my truck both of which sit for weeks at a time and have parasitic loads. Plus who wants to have to program clocks and radios every time? The 4 stage Smart chargers are a good solution for me. Even a 3 stage on a timer with regular loading of the batteries. IMHO of course.

Hi

....and what does that 4 (5,8 12 ...) stage charger do when it "sees" the parasitic drain from the "stuff" on the RV? With most of them all that fancy multistage stuff simply shuts down. You are right back to an "old style" charger.

Bob

[ITSNO60]

Originally Posted by uncle_bob

Hi

....and what does that 4 (5,8 12 ...) stage charger do when it "sees" the parasitic drain from the "stuff" on the RV? With most of them all that fancy multistage stuff simply shuts down. You are right back to an "old style" charger.

Bob

Not sure what you mean. It doesn't "see" a load, it monitors voltage and when it drops below a certain threshold it initiates a charge cycle. It starts with bulk but will quickly move to absorption if the battery is mostly charged (1-2 min on mine). Then a brief absorption charge followed by a 4 hour float, then back into storage. How is that just like an "old style" charger? An "old style" charger never comes off float.

[uncle_bob]

Originally Posted by ITSNO60

Not sure what you mean. It doesn't "see" a load, it monitors voltage and when it drops below a certain threshold it initiates a charge cycle. It starts with bulk but will quickly move to absorption if the battery is mostly charged (1-2 min on mine). Then a brief absorption charge followed by a 4 hour float, then back into storage. How is that just like an "old style" charger? An "old style" charger never comes off float.

Hi

Nope

A fancy multistage charger also looks at the current going out of the charger. It has no idea at all if the current goes to a load or the battery. It *assumes* that the current is all going to the battery. Pull this or that amount of current and it kicks into another "stage". Indeed it may never get out of this or that stage due to current flow.

How much current does this or that charger do this or that at? It's very much a "that depends" sort of thing. Small chargers likely trigger at small currents, but you can even find exceptions to that.

Bob

[Silvr_Bullet]

Should Lithium’s be kept on shore power, for instance when trailer is in intermittent use during a 6-8 month camping season? Would that shorten service life of lithium batteries

[ITSNO60]

Sorry but I don't find that to be true with the Victron, even though I have parasitic loads it stays in storage for many hours at a time with zero current flowing which can be verified by logging in. Maybe true with the other brands that are mass marketed.

[ROBERT CROSS]

Originally Posted by ITSNO60

Sorry but I don't find that to be true with the Victron, even though I have parasitic loads it stays in storage for many hours at a time with zero current flowing which can be verified by logging in. Maybe true with the other brands that are mass marketed.

^
Yes
I installed a battery cut-off switch and just charge completely and shut them off.
3 Seasons, SFSG.

Bob
🇺🇸

[ITSNO60]

Originally Posted by ROBERT CROSS

^
Yes
I installed a battery cut-off switch and just charge completely and shut them off.
3 Seasons, SFSG.

Bob
����

That would be my choice on a TT but for a MH & TV I need to leave connected.

[ROBERT CROSS]

Originally Posted by ITSNO60

That would be my choice on a TT but for a MH & TV I need to leave connected.

OOOP'S....brain fluff, fingers were faster than the control mechanism.

Bob
🇺🇸

[Wazbro]

Originally Posted by uncle_bob

Hi

You can get a dirt cheap timer without the WiFi to do the same sort of thing. If power goes out or there is some sort of spike, the mechanical ones are *very* hard to kill. It is becoming harder to find those .....

Bob

Sort of, but most of the cheap mechanical ones can only be set for daily not weekly. By the time you get to weekly it's cheaper to get the WIFI ones and if your trailer is were it has WIFI you can check your phone to see it's still working.
Many chargers go into bulk mode every time they get power then taper off as they figure out how much charge the batteries need, so i would rather only charge once a week in storage.

[kmrice]

Could anyone recommend a specific model Victron battery charger for this purpose? Thanks!

[ITSNO60]

Originally Posted by kmrice

Could anyone recommend a specific model Victron battery charger for this purpose? Thanks!

Either a IP-67 model if permanently mounting or a IP-65 model if using as a portable charger. I use the IP-65 12/15 on coach and 12/5 on chassis with permanent extensions fastened to the batteries which come out at the edge of the frame where I just plug in.

[uncle_bob]

Originally Posted by kmrice

Could anyone recommend a specific model Victron battery charger for this purpose? Thanks!

Hi

https://shop.pkys.com/Victron-Energy...th_p_7777.html

Is one of many. There are other mounting styles and current ranges.

7 day mechanical timer:

https://www.amazon.com/Intermatic-T2...%2C167&sr=8-51

Indeed they are not as common (or as cheap) as they once where.

Bob

[kmrice]

Originally Posted by ITSNO60

Either a IP-67 model if permanently mounting or a IP-65 model if using as a portable charger.

Thanks to both you and Uncle Bob!

Karl