Lilfo 105 LiFePo4 batteries flat.

jamie N said:
I know nothing about LifePo batteries, or their BMS systems, but do wonder if one can charge using a bench power supply, where one's able to manually set the A's & V's involved?
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That's a great idea .... why didn't I think of that!
I have a couple of 20v, 5amp bench power supplies. They have both current and voltage control.
I'm back home, batteries dumped in the hall for now.
I'll try them out tomorrow.
I've made two phone calls to Lifos, each with a promise of a return call.
But radio silence as yet, not impressed.
 
You do need to know the cell voltages. If they are terrible the batteries may be unrecoverable. If the BMS did its job and shut you down at say 2.5V/cell you may be OK and just need to charge up manually and the BMS will reset. Alternatively there may be a remote reset needed from an emergency shut down. I’d contact the battery maker for advice. - or God forbid, RTFM.
 
Zing said:
You do need to know the cell voltages. If they are terrible the batteries may be unrecoverable. If the BMS did its job and shut you down at say 2.5V/cell you may be OK and just need to charge up manually and the BMS will reset.
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Post #1 states "They are all flat, just 0.2v per battery." that isn't 2.5V per cell.
Zing said:
Alternatively there may be a remote reset needed from an emergency shut down. I’d contact the battery maker for advice. - or God forbid, RTFM.
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#21 states "I've made two phone calls to Lifos, each with a promise of a return call.
But radio silence as yet, not impressed."
 
PaulRainbow said:
Post #1 states "They are all flat, just 0.2v per battery." that isn't 2.5V per cell.

#21 states "I've made two phone calls to Lifos, each with a promise of a return call.
But radio silence as yet, not impressed."
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Are they really 0.2v? If so why are we continuing the discussion? It's game over. I suspect they may well not be.

Phone calls being ignored are not a good sign. Maybe email might work. Good luck to him.
 
If OP is using the BMS to measure cells - then that cannot be trusted if it has shut down. Plenty of YT vids on this ...

The cells could be still at or above 2.5V each ... but if the BMS has shut off - then it will only show zero or near zero ...

If OP has actually metered the cells direct - which I doubt - then 0.2V is dead !

I refer back to my post #18 ...

Worth a look at the vids and a try - if batts are dead - nothing lost by trying.
 
A reading of circa 0.2v per cell on a multimeter generally indicates that the BMS has shut off. The cells themselves likely wont be at 0.05V each.

0.2V is just some tiny current leakage through the BMS / capacitance.
 
jakew009 said:
A reading of circa 0.2v per cell on a multimeter generally indicates that the BMS has shut off. The cells themselves likely wont be at 0.05V each.

0.2V is just some tiny current leakage through the BMS / capacitance.
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You need to clarify that ... because if measurement is taken by multi-meter at the cells - then that has no effect from BMS... and 0.2v means cells dead.
If the cell voltages are quoted as per BMS - then yes - the BMS has most likely shut down.
 
Refueler said:
You need to clarify that ... because if measurement is taken by multi-meter at the cells - then that has no effect from BMS... and 0.2v means cells dead.
If the cell voltages are quoted as per BMS - then yes - the BMS has most likely shut down.
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Surely if its an off the shelf drop in battery, the OP doesnt have access at cell level? He can only measure what is at the battery terminals
 
Refueler said:
That is my point. The reading he's getting is unreliable as he cannot tell if its BMS shut down or not.
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He said it’s a lifos battery. Unless he has disassembled the thing it’s obvious he’s taking a reading after the BMS.

If the cells are actually at 0.2V, there is no way the BMS will be running anyway, so the BMS will still be shutdown.
 
Update:
I got a phone call from Solar Technologies (Lifos agents) this morning.
Quiet curt but useful.
The story:
Even if the batteries are completely disconnected, the BMS is still drawing power.
When the minimum voltage is reached the BMS cuts off the output, but still draws power.
Eventually the BMS will shut down, at around 5volts, but it is still connected and drawing power.
If the terminal voltage drops to around 2 volts it is impossible to wake the BMS up.
So I thought the batteries where dead!
That's about 300Ah in 6 months, that about 3.6kWh.
Every hopefull, I tried the bench power supply.
I set the voltage to 14.5volts, as advised by Solar Techologies, maxed out the current, nominal 5amps, and connected the power supply.
To my surprise, the battery responded with 5.2 volts and 5.14amps.
It took about 45mins to get to 11.82 volts, at that point I change over to a 5amp smart charger, and it worked.
1hr 30min later it's now at 13.00 volts. I don't know what the charge current is, but it's presumably maxing out the smart charger at 5amp.
The same thing happened with the second battery.
I'm at home, so I have very limited set of test and charging leads, so I can only charge 2 batteries at a time.
I'll tackle to two remaining batteries later.
I'm obviously happy that 2 batteries have been recovered, and that the 2 others will be ok.
Next job is to get them back to the boat and connected to the multiplus, then run a 1kW load for 1hr to see if I can detect any permanent loss in capacity.
Thanks for all the replies, all "grist to the mill" in helping me understand what was going on.
As foot note, I wouldn't use Lifos again, I think the batteries are quite good, but they are now ridiculously expensive and I really don't like their attitude to customer service.
 
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Having gone through a saga with my LiFePo4 battery and the rubbish advice from seller and his supplier ... I am not surprised by your post ... I doubt that your info and mine was from a real Tech guy ... probably from sales desk ...

There are plenty of videos online showing that BMS does wake up even when battery has hit zero !

It takes a quick shock dab of 12 - 14V - as the LiFePo4 will literally within that second or so hit 10+V ... enough for all to wake up and function.

Here's a video showing what I mean ... it does not matter that the battery in video is only 8AH .. it works for all sizes ... (Youtube has videos for big and small doing exactly same).

 
Refueler said:
Having gone through a saga with my LiFePo4 battery and the rubbish advice from seller and his supplier ... I am not surprised by your post ... I doubt that your info and mine was from a real Tech guy ... probably from sales desk ...

There are plenty of videos online showing that BMS does wake up even when battery has hit zero !

It takes a quick shock dab of 12 - 14V - as the LiFePo4 will literally within that second or so hit 10+V ... enough for all to wake up and function.
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Another use for an emergency parallel switch then Nigel, a short shot of power from the engine battery should wake the BMS.
 
PaulRainbow said:
Another use for an emergency parallel switch then Nigel, a short shot of power from the engine battery should wake the BMS.
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Never thought of that !!

Reminds me of the old NiCd days ... when the NiCd would give up being charged ... due to crystals forming .... to get temporary use out of the cell - give it a shock burst from a full charged cell ... basically it broke down the crystals ... but was only a short term fix.
 
I thought of using the engine starter battery to kick the 4 Lifos batteries into life. But I was concerned that switching in an AGM with a CCA of 700 amps, could do substantial damage to 4 very expensive batteries. Both batteries have very low impedance. I could envisage 1,000amps or more flowing.
When I connected the 5amp bench power supply a LiFePO4 battery, it immediately maxed out the bench power supply at 5.15amp. I guessed that this current limited supply would be enough to start the BMS, but not enough to cause any damage.
In an emergency I would probably tried it, but the boat is ashore until next April, so no problem to wait a while and research and think about.
 
I've managed to recover all 4 batteries and fully charged them.
I made a short video of connecting the last one to the bench power supply.
Notes:
The max voltage was initially set to 14.4 volts, as per Lifos's instructions.
When the power supply is turned on, the voltage on the supply sequences through, 0.0v, 14.5v then about 5.5volts, and the power supplies current quickly moves to 5.15 amps, as the current limiter kicks in.
The voltage then climes quickly over the first minute to just over 10 volts.
I left the bench power supply on until the voltage got to about 12volts, then transferred the battery to a smart charger to complete the charge.
I didn't want to run the bench supply, in what is essentially an overload situation, for longer than necessary. I don't think that hey are designed to run flat out for extended period. Having said that the power supply worked well, with the fan cutting in and out as required to manage the thermal load.


I hope the link works, it's the first time I've tried making a YouTube video in pasting the link into a post.
I can open it in a new TAB but don't appear to be able to open it directly in the forum.
 
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