Redjo wrote:

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Hello Radar;
Just a thought, do you have battery monitor for the Lithium battery to know what energy goes in and what comes out of your battery to give SOC?; just reading the voltage on a Lithium battery can be a trap as the voltage remains constant for about 85% of the charge then plummets dramatically for the last 15% of storage, you may be working close to the threshold point.
Kindest Regards
Joe H.

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 Yes to that, the solar regulator informs me that there was a reading of 13.1 volts when the system shut down.

The second night we went to bed and the reading was 13 volts plus but at 2 am when I wanted a drink of water the system shut down.

PS, I have rung the retailer and he informed me that there has not been any issues.

Mind you, that have only been marketing lithium LiFeOp4 battery for a short period.

Radar wrote:

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320 watts of solar. .......

 

....... showers in the morning were wonderful

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 Does this mean you are heating the water using battery power (plus other electrical usage)? It depends on how much hot water you use, but my system at home uses about 1.5 - 1.8 kWh every day. That is more than the total capacity of your battery. 320 watts of solar to recharge the battery AND reheat the water is probably stretching the capabilities.

As a test, try being very frugal with hot water for a couple of days and see if that solves it.

Are We Lost wrote:

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Radar wrote:

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320 watts of solar. .......

 

....... showers in the morning were wonderful

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 Does this mean you are heating the water using battery power (plus other electrical usage)? It depends on how much hot water you use, but my system at home uses about 1.5 - 1.8 kWh every day. That is more than the total capacity of your battery. 320 watts of solar to recharge the battery AND reheat the water is probably stretching the capabilities.

As a test, try being very frugal with hot water for a couple of days and see if that solves it.

 

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 No, I am not using the battery to power the 3 way.

The most we have consuming battery power is 6 led lights and the water pump.

I repeat, no television,  no electronic at all. Just a few lights to read by.

Radar wrote:

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 No, I am not using the battery to power the 3 way.

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It was not me who suggested that. I was asking about hot water based on your comment   .....

"showers in the morning were wonderful with minimal use of the battery after sun down"

So based on your response the shower is unrelated to the issue?

Dick0 wrote:

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Hi Radar, No idea of your overall system so difficult to comment.

Do you charge with solar or dc>dc or 240V charger. Is the charging set to Lithium charging values?

Do you use an inverter for 240V use?

What type of HWS do you use?

What battery monitor have you connected to the Lithium battery?

Etc, etc.

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 DickO, our system is very simple.

320 watts of roof top solar feeding a Voltech regulator into the Powertech lithium battery 12 volt 125 amp lithium battery.

Do not have any other way of charging.

I was using a AGM deep cycle 110 amps but it life was nearing its end after 4 years and all worked fine.

We are not heavy uses of 12 volt power.

Gas hot water, gas refrigeration.

Mainly double A batteries after dark.

Dick0 wrote:

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 DickO, our system is very simple.

320 watts of roof top solar feeding a Voltech regulator into the Powertech lithium battery 12 volt 125 amp lithium battery.

Do not have any other way of charging.

I was using a AGM deep cycle 110 amps but it life was nearing its end after 4 years and all worked fine.

We are not heavy uses of 12 volt power.

Gas hot water, gas refrigeration.

Mainly double A batteries after dark.

*****************************

Hi Radar, so I'll assume you changed the battery to Lithium and continue using the solar system as used for previous AGM battery.

I'll also assume the solar controller is a PWM type that cannot be programmed for LiFePO4 and suitable only for wet-cell batteries, or MPPT nonprogrammable for wet-cell only.

In the first instance I would disconnect the solar and attempt to charge the Lithium with any 240V/12V battery charger for several hours to raise the voltage of the battery. The Lithium BMS should prevent overcharging.

You may have depleted the battery, during your initial testing/usage, below the minimal voltage for controller to recharge.

When done, connect the solar controller and it should display the level of solar charging to the Lithium.

I would, also, use a MPPT programmable charger with LiFePO4 user programmable settings, which are quite different to AGM settings.

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 Hi DickO

I have this morning disconnected the Lithium battery and in the process of hooking up the old AGM battery to check if everything is 12 volt electrical ok.

We will be replacing the 7 year old Voltech solar regulator that has worked well with the AGMs. I believe the Voltech has been a good product and made in Brisbane, on 2 occasions were more then helpful with info and ringing back the next day to check to make sure all was good.

What I still can not understand is why the regulatory monitor is reading 13.4 volts. Switching 10 led lights on and the water pump, the battery shuts down. I now have the battery on the bench and reading 6 volts.

Thank you for your reply.

Hi Radar,

Ok the first thing.  Did you disconnect your solar before connecting up the solar regulator to the battery. Your Voltech charger will give false readings and possibly go haywire if you did not.  If not disconnect the solar and then disconnect the battery.  Connect the battery up first, wait till it gets a battery voltage reading and then connect your solar. You will only be able to do this once you have jumpstarted your battery again. 

I have been helping someone out who did similar with a Voltech controller and killed it.

You have spent a small fortune on a lithium battery and I can only suggest that you invest a little more into a decent MPPT solar controller.

If you battery is only showing 6V across the terminals then you need to get it charged up very quickly but it should never have gone that low and the BMS should have cut out at the low voltage cut out which is generally about 10 to 10.5V although some battery manufacturers set the BMS at a higher cut out voltage.  It may actually be higher than 6V but that is just the reading you are getting through the BMS in protection mode.

We can look at whether it is your BMS once you have the battery charged up and running.

Tim

Dick0 wrote:

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Radar wrote:

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 Hi DickO

I have this morning disconnected the Lithium battery and in the process of hooking up the old AGM battery to check if everything is 12 volt electrical ok.

We will be replacing the 7 year old Voltech solar regulator that has worked well with the AGMs. I believe the Voltech has been a good product and made in Brisbane, on 2 occasions were more then helpful with info and ringing back the next day to check to make sure all was good.

What I still can not understand is why the regulatory monitor is reading 13.4 volts. Switching 10 led lights on and the water pump, the battery shuts down. I now have the battery on the bench and reading 6 volts.

Thank you for your reply.

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 Hi Radar, looks like the Lithium battery is totally depleted. Put it on a 240V/12V car battery charger to get the voltage reading up to at least 11.5 or higher volts so that the solar controller will be able to charge it further.

It appears the reg monitor is still holding the initial fully charged voltage reading at 13.4volts, which is about 95% SOC, (default BMS float control).

If or when you get the charging under control could you please post the results here.

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 Hi DickO

Have installed a new lithium LiFeOp4 solar controller and after a lengthy chat with  the supplier Tech Person all is good.

I did remove and charge the lithium battery up as soon as I was home from the caravan.

3 days on after installing new controller everything looking good.

We will road test it next week when we do a short trip over Easter.

Thank you very much for your time.