Hi,

 

I recently bought two new CFE 1280S 12V Lithium Ion batteries from a retailer in Pretoria and when I opened them they were both discharged with only 2.2V remaining. Their built-in BMS has shut down and my inverter also do not detect them. I have heard that you can "wake-up" an over discharged Lithium Ion battery by applying a 12V current and then very slowly recharge them, but some online articles state there could already be damage with a reduced expected life.

 

I this normal for batteries in storage and should I try and revive them or I return them?

Any advise would be appreciated.

 

You should definitely return them . They shouldn't be much lower than 12v new.

On 2022/06/21 at 2:53 PM, BenS said:

this normal for batteries in storage

It is normal for batteries to self-discharge over time in storage and they are usually given a top up charge every 6 months or so. Perhaps your supplier didn't have the facilities to do this, but batteries should not go that low and they will have a shortened lifespan. I'd say take them back and get your money back unless they have a very good reason (hopefully some kind of documentation from the manufacturer) for why they are so low. I don't know this specific battery, but it doesn't seem right, if it says 12.8V on the side then it should be 12.8V at least.

...I just had a thought that there might be some switch, cable or jumper inside the battery that would need to be activated for it to work properly. Maybe they store it like that so there is no real voltage across the terminals... just a thought.

My rule of thumb . dont open something u bought brand new if it doesnt work  2 ask for ut to betested in store when u retyrn it and the replacement shouls be tested as well

I think they will go into standby if no load/charge is detected within a certain time. Try to wake them up by applying a voltage to the battery, as if to charge so it has to be current limited. If the BMS was in standby, it should wake up and connect the battery voltage to the terminal.

definitely return.
Transport and storage should be above 30% at least.
Ask for replacement and test in store or get money back.

Update: The retailer replaced both batteries with new ones with a full charge. Contacted the manufacturer and they also indicated that I should return as the voltage should never be that low.

 

Thanks for all the feedback and advice.

What has been the performance of the replaced batteries to date. I have been considering buying the same , what's your comment or anyone who has used the CF 1280s Lithium Battery.

So far everything seems to work fine. Ran on backup for up to 6 hour slots now with about 500W office load and so far no need to shut down (was never able to do this on the gel batteries). Difficult to gauge DOD as my inverter does not indicate this accurately for Lithium batteries.

On 2022/07/04 at 8:35 PM, BenS said:

So far everything seems to work fine. Ran on backup for up to 6 hour slots now with about 500W office load and so far no need to shut down (was never able to do this on the gel batteries). Difficult to gauge DOD as my inverter does not indicate this accurately for Lithium batteries.

Could you please provide further feedback on these lithiums? They tick all the right boxes for me. TIA

6 minutes ago, DenBeech said:

Could you please provide further feedback on these lithiums? They tick all the right boxes for me. TIA

 

So far so good. They run my office load for up to 10 hours before reaching their max DOD cut-off. Will obviously have to see in the long run how they last.

36 minutes ago, BenS said:

 

So far so good. They run my office load for up to 10 hours before reaching their max DOD cut-off. Will obviously have to see in the long run how they last.

Many thanks for the feedback. Sincerely appreciated.

Can someone advise me what the 20% DOD voltage is for Lit-ion batteries linked to a 48V inverter/charger.

My cut off voltage is set at 48 volts and float is 50 Volts,

Any advice please.

The actual voltage for 20% not that easy to determine with these types of chemistry.

AFAIK Most BMSes cut-off are set at about 3V which should be pretty close to 20%
so for 16 cell battery that would be 48V
and for 15 cell batteries that would be 45V

34 minutes ago, WannabeSolarSparky said:

The actual voltage for 20% not that easy to determine with these types of chemistry.

AFAIK Most BMSes cut-off are set at about 3V which should be pretty close to 20%
so for 16 cell battery that would be 48V
and for 15 cell batteries that would be 45V

Yea you cant realy use voltage at all if you want to be accurate . my cells are just above 3V at 5% SOC.

5 minutes ago, Nexuss said:

Yea you cant realy use voltage at all if you want to be accurate . my cells are just above 3V at 5% SOC.

Correct yes, this differs vastly from battery to battery. Best way really is to use coulomb counting. But even then still not that accurate.
Best IMO is to "learn" your batteries behaviour and use the readings as a simple guided estimate.

2 hours ago, JRW said:

Can someone advise me what the 20% DOD voltage is for Lit-ion batteries linked to a 48V inverter/charger.

My cut off voltage is set at 48 volts and float is 50 Volts,

Any advice please.

Did you mean 20% DOD or 20% SOC meaning 80% discharged. A number of 12V lithiums have a cut out from BMS at 11V. I only discharge mine down to about 12.4V. Not a lot of energy left between 11.5 and 12.4V.

On 2022/09/13 at 8:34 PM, Scorp007 said:

Did you mean 20% DOD or 20% SOC meaning 80% discharged. A number of 12V lithiums have a cut out from BMS at 11V. I only discharge mine down to about 12.4V. Not a lot of energy left between 11.5 and 12.4V.

Yes, I mean state of charge, I want to discharge to 20% SOC and charge to 90% SOC. I have two 2.4 kWh Lith-ions in parallel. 48 V system.

I need advice on what to set on the inverter/charger panel.

Thanks

Edited September 15, 20223 yr by JRW
atteched

On 2022/09/15 at 5:10 PM, JRW said:

I have two 2.4 kWh Lith-ions in parallel. 48 V system.

You'll need to be more specific on the brand and model of the batteries to be sure as they can differ.

Pylon, Synapse branded batteries and inverter,

1 minute ago, JRW said:

Pylon, Synapse branded batteries and inverter,

The other option one may be able to help with is the 6 green indicators on the battery, if there are two lights on what SOC is indicated, 20%, 30% ?????

On 2022/09/13 at 5:44 PM, JRW said:

Can someone advise me what the 20% DOD voltage is for Lit-ion batteries linked to a 48V inverter/charger.

My cut off voltage is set at 48 volts and float is 50 Volts,

Any advice please.

I would go for maybe 47v and 51v.It wont be spot on but should put you close to the figures you want.(bit of a thumb suck)

I can however tell you that a 46v setting allows my system to drop to about 11% and 52.5v Charges up to 100%.

 

 

6 hours ago, Piper said:

I would go for maybe 47v and 51v.It wont be spot on but should put you close to the figures you want.(bit of a thumb suck)

I can however tell you that a 46v setting allows my system to drop to about 11% and 52.5v Charges up to 100%.

 

Thanks that's reassuring to what my thoughts are.

On 2022/09/10 at 8:14 AM, BenS said:

 

So far so good. They run my office load for up to 10 hours before reaching their max DOD cut-off. Will obviously have to see in the long run how they last.

 

Well, one of my 5 month old CFE 1280S batteries has died and refuses to charge. I urgently need a replacement. Would it be a bad idea to mix another brand battery with similar specs (i.e. Hubble S100) with the working 1280S (my inverter needs 2 x 12V)?

11 hours ago, BenS said:

 

Well, one of my 5 month old CFE 1280S batteries has died and refuses to charge. I urgently need a replacement. Would it be a bad idea to mix another brand battery with similar specs (i.e. Hubble S100) with the working 1280S (my inverter needs 2 x 12V)?

@BenS  They have a 5 year warranty, will be interesting to hear what the suppliers say when you take it back to them