Sinopoly LiFePO4 instructions for storage.

[rvlandlubber]

Greetings Seafarers,
Hoping someone may be able help with some information I’m chasing specifically relating to Sinopoly LiFePO4 cells.

I would like to know the manufacturer’s instructions for long term storage.

Searched without success for the Sinopoly version of the user manuals that Winston and CALB produce that contains this info.

The Sinopoly spec sheets only mention storage temp but no SoC instruction.
Tried emailing Sinopoly but no reply.

Ideally, manufacturer’s instructions, if they exist, would be great.

Thanks in advance

[Delfin]

Originally Posted by rvlandlubber

Greetings Seafarers,
Hoping someone may be able help with some information I’m chasing specifically relating to Sinopoly LiFePO4 cells.

I would like to know the manufacturer’s instructions for long term storage.

Searched without success for the Sinopoly version of the user manuals that Winston and CALB produce that contains this info.

The Sinopoly spec sheets only mention storage temp but no SoC instruction.
Tried emailing Sinopoly but no reply.

Ideally, manufacturer’s instructions, if they exist, would be great.

Thanks in advance

Can't help you on a specific manufacturers recommendation, but the consensus is around 50% SoC, measured by an amp hour used counter and nominal capacity of the bank. Part of the puzzle is how "long term" is long term?

[rvlandlubber]

Originally Posted by Delfin

Can't help you on a specific manufacturers recommendation, but the consensus is around 50% SoC, measured by an amp hour used counter and nominal capacity of the bank. Part of the puzzle is how "long term" is long term?

Hi Delfin

In my case, long term storage would typically be around 4 months.
This is probably not unusual for RVers not on the road permanently.

[coopec43]

Can't help you with a user manual.

Did you see the videos?

Is this any help

https://www.cycle9.com/wp-content/up...ery-manual.pdf

Clive

[Delfin]

Originally Posted by rvlandlubber

Hi Delfin

In my case, long term storage would typically be around 4 months.
This is probably not unusual for RVers not on the road permanently.

Then 50% SoC s/b fine then. I've observed no voltage drop from self discharge for up to 3 months. Perhaps install a decent voltmeter measuring voltage at the battery to monitor, even though the voltage curve is basically flat between 80% discharged and 90% charged. It will give you peace of mind. I assume you are using a BMS to manage low/high voltage events?

[rvlandlubber]

Thanks for those replies and link.

I’m really trying to dig a bit deeper for the Sinopoly cells info in particular.

The concensus opinion of 50% SoC has worked for me.

Ihave a 12 Volt 200Ah pack of Winstons in my van that I installed 4 years ago. During that time, I would estimate that the battery would have spent an accumulated total of 2.5 years isolated at around 50% SoC.

I performed a discharge test a few weeks ago and the battery provided 221.6Ah. The BMS disconnected the load when one of cells discharged to the protection setting of 3.0 volts.
Discharge current for the test was 30 amps continuous.

I’m reasonably confident that there hasn’t been any significant capacity reduction while in storage.
The concensus view of 50% is also consistent with Winston’s storage recommendation.

The reason for my question about Sinopoly:
I’m aware of some fellow RVers recieving advice from from a vendor that its ok to leave Sinopoly Lifepo4 battery in storage, on float charge of 13.5volts indefintely.
IMO this is bad advice.
So with either Winston or CALB the partial charge storage instructions are clear in their user manuals.
Just can’t find this info from Sinopoly.
I would like to ensure that any advice I give them is consistent with the cell manufacturer’s instructions.

[john61ct]

Chemistry is chemistry.

Anything above 3Vpc is fine, long as you are 100% sure there will not be discharge to / below that point.

Can you isolate the cells themselves?

If I were doing it for the first time, without the ability to check on them every few weeks,

then I'd stick to 3.2 - 3.3Vpc resting.

Cooler the better.

[john61ct]

Originally Posted by rvlandlubber

some fellow RVers recieving advice from from a vendor that its ok to leave Sinopoly Lifepo4 battery in storage, on float charge of 13.5volts indefintely.
IMO this is bad advice.

Well better than letting them go flat, in a case where the parasitic loads can't be disabled and no one reliable is around to check on them.

But while I agree with the premise that no Float at any voltage is best for optimizing longevity,

I think given most owners are more nitpicky than I, any actual short-term "damage" is unlikely, long as the gear doesn't fail.

But you are putting a lot of trust in your gear not failing.

And a lower voltage would be better, as I gave above.

[rvlandlubber]

Originally Posted by john61ct

in a case where the parasitic loads can't be disabled

Thanks John,
I think you hit the nail on the head there.
This would probably be the reason for the vendor advice.
But when you think about it how hard can it be, at design stage, to make sure the system battery can be properly isolated for storage?
So this design consideration gets overlooked and they have to come up with a shabby work around.
And yes you do have to have a lot of trust in your charging source not failing, or simply being left unplugged by some wanting to use the power point!
As mentioned previously, my batteries spend more than half their life not in use.
Storage was certainly thought about when I put my system together.

[john61ct]

I imagine some designers do not trust the user, want the "protections" always enabled, and that requires constant power while stored.

And I have concluded that very long-term longevity is definitely **not** highly prioritized by vendors, and in fact many design elements and recommendations work against that goal.

[Delfin]

Originally Posted by rvlandlubber

Thanks John,
I think you hit the nail on the head there.
This would probably be the reason for the vendor advice.
But when you think about it how hard can it be, at design stage, to make sure the system battery can be properly isolated for storage?
So this design consideration gets overlooked and they have to come up with a shabby work around.
And yes you do have to have a lot of trust in your charging source not failing, or simply being left unplugged by some wanting to use the power point!
As mentioned previously, my batteries spend more than half their life not in use.
Storage was certainly thought about when I put my system together.

Seems like anyone with a 1-2-both switch, or ACR plus a BMS has all the components needed to isolate the LFP bank from any load, parasitic or not.

[Maine Sail]

Originally Posted by Delfin

Seems like anyone with a 1-2-both switch, or ACR plus a BMS has all the components needed to isolate the LFP bank from any load, parasitic or not.

Unless the BMS's parasitic loads can't be turned off. Early Mastervolt LFP's and a number of sealed drop-in batteries lack a BMS isolation feature. Granted this is usually a very low quiescent draw but it really should be kept in mind. At the very least the battery maker should be able to tell you what the quiescent draw of their own BMS system is..

[noelex 77]

Keep in mind that there are two types of battery “storage” that are needed on a boat:

The first is when all loads can be removed and nothing needs to operate. I presume the OP is talking about this case.

The second is when equipment may be required. The most common scenario is storing the boat in the water when bilge pumps are needed. There are even some owners who argue bilge pumps should be left operating when the boat is stored on the hard. I have seen boats significantly damaged by rainwater accumulation when stored ashore.

There is is also sometimes a requirement for other equipment such as alarms etc. The draw may be small, but it becomes significant without charging when the boat is stored for several months.

[Delfin]

Originally Posted by Maine Sail

Unless the BMS's parasitic loads can't be turned off. Early Mastervolt LFP's and a number of sealed drop-in batteries lack a BMS isolation feature. Granted this is usually a very low quiescent draw but it really should be kept in mind. At the very least the battery maker should be able to tell you what the quiescent draw of their own BMS system is..

Ah, thank you. I thought all BMS's could isolate the pack.

[Delfin]

Originally Posted by noelex 77

Keep in mind that there are two types of battery “storage” that are needed on a boat:

The first is when all loads can be removed and nothing needs to operate. I presume the OP is talking about this case.

The second is when equipment may be required. The most common scenario is storing the boat in the water when bilge pumps are needed. There are even some owners who argue bilge pumps should be left operating when the boat is stored on the hard. I have seen boats significantly damaged by rainwater accumulation when stored ashore.

There is is also sometimes a requirement for other equipment such as alarms etc. The draw may be small, but it becomes significant without charging when the boat is stored for several months.

As noted, a 1-2-both switch, or ACR plus a BMS (that isolates the pack) handles at dock loads just fine while eliminating the need for floating the LFP for months at a time. Dock loads on my boat are supplied by the starter bank when we are away for a period of time.