We use our 9 year old 300Ah LiFePO4 battery 24/7 and it has never been "stored".
If we were to store our motorhome for more than a month without use I would isolate the battery and walk away. Longer than 6 months and I would probably arrange for someone to check the battery and top up if necessary.
My opinion only. 50% or 100% SOC is irrelevant. Take your pick or follow one of thousands of other opinions based on, well not much.
At the end of battery life you will never know what you missed anyway.
I have lithium throughout my van - changed over from deep cycle 12 months ago.
I have followed what seems to be the premier recommendations for long term shut-down
and have disconnected the battery totally at SOC 80%.
My Van people say that I should not.
While totally disconnected from power (other than solar) some items show slight activity
like - the antenna booster gets hysterical and flashes, the exhaust fan runs at very slow
speed and so-on.
I don't think that this is right, and worry re fires, fusing, wear of implement etc
The van people say "You shouldn't disconnect the battery".
Whats the thoughts of interested members?
B
Brodie,
Cell manufacturers, that is the cells inside your battery, do recommend that LiFePO4 not be fully charged when in storage. I have read that some consider 3 months to be storage. I dont bother and just leave mine connected to solar but it is a matter of personal choice. For me if I get 3000 discharge cycles as opposed to 5000, remembering that they will still supposedly have 80% of their capacity, Im not concerned as Im sure my batteries will probably outlive my caravanning days.
You say you have disconnected your batteries but remember you will need to disconnect the solar from the controller first before connecting your batteries back up. So you connect your batteries to the solar controller and then the solarpanels to the solar controller.
You say when totally disconnected from power. Do you mean disconnected from battery too or do you mean 240V power.
What solar controller do you have and does it have load terminals with cables connected.
No need to disconnect the battery just disconnect the solar. Just keep an eye on the battery for a while to see if any parasitic current is being drawn.
Tim
-- Edited by TimTim on Wednesday 13th of December 2023 10:18:07 AM
Solar still connected but nowhere to go, so the fact that there's a tiny bit of current is disconcerting.
How is it getting to the system loads at all?
Everything is Enerdrive.
They recommend disconnection of the battery for long term storage, but like someone said, qualify long term.
The batteries are evidently less stressed at around 80%.
I also like to know that there's no power anywhere - who knows a rat or water of whatever could create a short
and then POOF!
The tiny bit of current can only be through the solar controller. There should be a low battery voltage setting for the load terminals but the only way you can check that it is set up is to disconnect the solar panels and reconnect the battery. It is generally set up as a default setting anyway.
The only other explanation I can give is that I have seen some solar controllers go haywire when only connected to solar or connected to solar first.
As I said previously, no need to disconnect the battery but if you want your battery to not be fully charged whilst in storage simply disconnect the solar panels from the controller.
Even a tiny 20mA draw from somewhere would completely exhaust a LiFePO4 100Ah battery stored at 80% within 6 months. Hopefully any inbuilt BMS would be smart and reliable enough to protect the cells.
I would still prefer and recommend the guaranteed zero current draw with battery isolation.
We also have a circuit breaker between the panels and controller. Everything off for us.
-- Edited by Scubadoo on Wednesday 13th of December 2023 05:13:40 PM
We stored our new van under a cover for 2 months then just before leaving on a trip I removed the cover and connected the 240V supply to get the fridge cold. All the 240V appliances worked fine but nothing on the 12V circuit did. Even the fridge could not be swapped to a different supply source as the front control panel operates on 12V, I checked all the fuses etc. and assumed that somehow the Lithium batteries had run down I thought no problem they will recharge now that the panels are uncovered unfortunately they didnt,. I also have a DC/DC charger but running the car made no difference either. I went down to the dealer who we bought it from for advice, he rang the builder who put us through to the battery supplier. They said that the Lithium batteries were probably below minumum voltage for the charger to see them and would need to be kicked back into life. They also said although there is an inbuilt protection system if we had not isolated the 12V supply and a very low trickle discharge such as a light being left on the system may not have been seen it. They advised me that if the batteries had been damaged for that reason and not able to be brought back it would be considered as misuse by the customer and not covered under the warranty. Repalcement batteries would cost me around $3K but being the good guys that they were they would consider going me halves. Luckily the batteries were removed put on an external charger and brought back to life with no damage done. They advised us whenever you put your van in storage especially under a cover without an external panel connected make sure that you have turned off the 12V system there is no need to dissconnect the batteries. Sure enough with the power back on I opened the tunnel boot and an interior light had been left on. I think what happened is that while it was under cover sometimes we would go inside to do something and turn on the 12V system to use the interior lights obviously on the last visit we forgot to turn it off again - unfortunately with the light on in the tunnel boot all the ducks lined up. I dont know if its related to the lithium problem we had but on our recent lap the breakaway battery alarm would sound every time you put your foot on the brake and the red light for low battery would come on. Even after driving hindreds of kms it made no difference I ended up replacing it in Broome where they had a place that specialised in 12v systems they told me the battery was cactus. it was only 4 months old so I dont know if the problem we had with the lithium batteries somehow affected it or if it was just a faulty battery - the breakaway battery in our previous van was over 6 years old and still going strong.
BB
-- Edited by The Belmont Bear on Thursday 14th of December 2023 09:29:15 AM
Satellite battery management has a "touch" more costly management issues than us ground based itinérance entities, even if in stationary "orbit".
Maintaining a narrow charge/discharge window will allow the batteries to have a longer life.
But few dozen cappuccinos or an unexpected night our with Wifey or some new A grade silk lingerie, will create better returns than fluffing around with battery longevity battery issues.
I run 4 x 26AH gel batteries mostly for fridge, have run fridge continuously for 18 months. Least of my worries are battery issues.
there has to be wiring issues for there to be current in the system emanating from the
solar - and since the solar feeds the batteries which are disconnected from the system
the solar is therefore disconnected from the system. (?)
So I'm thinking that an error in wiring must be sorted.
No your solar panels are connected to the solar controller and in all probability your solar controller may have terminals supplying your loads. If that is the case then as I said earlier the issue is with the solar controller and it is the solar panels that need to be disconnected from the circuit before disconnecting the battery.
Simple test, test your exhaust fan during the day then test it at night . But if you have a multimeter do tests on the load terminals to see what the voltage is.
Attached are two photos on Enerdrive controllers. The terminals with the lightbulb are the load terminals and are generally located on the right of the other terminals.
Tim
-- Edited by TimTim on Thursday 14th of December 2023 01:58:22 PM
-- Edited by TimTim on Thursday 14th of December 2023 02:54:33 PM
Just disconnect the negative off the battery/s like in a car. If you are really not sure then disconnect the positive terminals as well after doing the negative.
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No your solar panels are connected to the solar controller and in all probability your solar controller may have terminals supplying your loads. If that is the case then as I said earlier the issue is with the solar controller and it is the solar panels that need to be disconnected from the circuit before disconnecting the battery.
Simple test, test your exhaust fan during the day then test it at night . But if you have a multimeter do tests on the load terminals to see what the voltage is.
Attached are two photos on Enerdrive controllers. The terminals with the lightbulb are the load terminals and are generally located on the right of the other terminals.
Tim
-- Edited by TimTim on Thursday 14th of December 2023 01:58:22 PM
-- Edited by TimTim on Thursday 14th of December 2023 02:54:33 PM
Good Tim, will do.
But there's only a tiny leak of current - if the solar was connected to the loads I reckon that there would be 60 or something amps. (?)
As I have said I have known solar controllers go haywire when connected to solar panels only. So anything can be happening. In most cases manufacturers of controllers will tell you to connect the controller to the battery and then connect the solar panels to the controller. They then state to disconnect in reverse order. By just disconnecting the battery you have gone against most manufacturers recommendations so we have no idea what the outcome is for any particular controller when you disconnect from the battery and leave the panels connected.
As I said, simple test is to see if what you are seeing it is happening at night too. If not then you know it is the solar controller.
We don't isolate solar or batteries when parked up. We turn radio on, gas off, then lock the door. Hitch lock applied, wheels chained, ensure insurance is paid up.
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It isn't necessarily a "tiny bit of current from the solar" either. It could be whatever the rating of your solar panels is, and in many cases enough to run half your rig with battery disconnected.
Most good solar regulators briefly supply normal end of charge voltage before settling back to float mode at around 13.5V
I have the solar connected directly to the battery so that for long term storage I can isolate the rest of the system while allowing the solar to maintain the battery at around 70% by reducing the charge voltages accordingly. (for lithium). For AGM, supposedly 13.2 is better
. But if you have a multimeter do tests on the load terminals to see what the voltage is.
