DC/DC and mains charger settings for Lifepo4: Nordelletronica NE325 and NE287

[Louisesjpp]

I've replaced my 150Ah AGM with two 100Ah lithium batteries. The battery supplier, EcoWorthy, says that lead acid chargers are fine for these batteries if they deliver 14.5volts. My own research suggests that float and trickle are best avoided.

The question then is how to set the dipswitches on the DC/DC (NE325) and the mains charger (NE287) ?

The mains charger has options for Pb flooded, Pb flooded with EBC enabled, gel, desulf or AGM. The DC/DC has dip switches S and S2 but don't say what they do.

Notes: newer versions of both these chargers have lithium options: mine do not.

I know the best option is to buy the right kit. However, we go away for a long trip on Friday so I cannot buy the right kit before we go, and at maybe £300 for the DC / DC and £150 for the mains charger, I'm a bit reluctant.

 

[Lenny HB]

I've just had a look I could only find the settings for the version with Lithium.

If you can find the setting either Gel or Lead should be OK temporarily but do not use the AGM setting the voltage will be too high.
On the new one the I think the Lithium setting the voltage is too high I wouldn't use one.

For a cheaper B2B (DC to DC) have a look at Renogy a few Funsters using them. The 40 amp one is on offer at £120.

 

[Louisesjpp]

I've just had a look I could only find the settings for the version with Lithium.

If you can find the setting either Gel or Lead should be OK temporarily but do not use the AGM setting the voltage will be too high.
On the new one the I think the Lithium setting the voltage is too high I wouldn't use one.

For a cheaper B2B (DC to DC) have a look at Renogy a few Funsters using them. The 40 amp one is on offer at £120.

This is the link to the DC/DC charger I have, it does have a page in English: https://img1.wsimg.com/blobby/go/a5... DC-DC converter manual.pdf?ver=1618941333480, and this is the mains charger: https://www.12voltplanet.co.uk/user/downloads/Nordelettronica-NE287-instruction-manual.pdf

Good tip for Renogy, a much more reasonable price. I'll probably make the trip to the UK from Spain on a gel or lead setting and buy the proper kit in the UK. The battery will only be seeing the charger while motoring, most of the time it will be charging from solar which does have a lithium setting. We don't plan to hook up.

 

[autorouter]

My own research suggests that float and trickle are best avoided.

The float and trickle charge settings are for a lead-acid type of battery. These voltage settings will not 'float' a lithium battery, they will just sit there doing nothing, which is fine.

The rest voltage of a battery is the voltage when it is not connected to anything, ie no loads and no chargers.

If the power supply voltage is a couple of volts higher than the resting voltage, then it will overcome the resting voltage and send a charging current into the battery. This is what happens during the bulk charging stage.

If a power supply is connected with a voltage set to lower than the battery rest voltage, the battery will try to send current into the power supply. However the one-way diodes in the power supply will stop any current flowing.

If the power supply voltage is gradually increased from the resting voltage, at some point a very small current will flow into the battery. Ideally this current is just enough to compensate for any internal self-discharge of the battery. This voltage is called the float voltage, and the process is called float charging or trickle charging.

The float voltage of a lead acid battery depends on many things, including the concentration of the acid inside the cells. It's about 13.4V to 13.8V.

So what happens if you apply a lead-acid float voltage to a fully charged lithium battery? It is below the resting voltage of the battery, so nothing will happen. It's too low to be a float voltage for a lithium battery.

You are quite right that if you somehow arranged the voltage so that the lithium battery was being float-charged, then that is a bad idea for a lithium battery. They have extremely low self-discharge, and don't need float charging. However a lead-acid float charge voltage won't cause any problems.

 

[SMB]

I've replaced my 150Ah AGM with two 100Ah lithium batteries. The battery supplier, EcoWorthy, says that lead acid chargers are fine for these batteries if they deliver 14.5volts. My own research suggests that float and trickle are best avoided.

The question then is how to set the dipswitches on the DC/DC (NE325) and the mains charger (NE287) ?

The mains charger has options for Pb flooded, Pb flooded with EBC enabled, gel, desulf or AGM. The DC/DC has dip switches S and S2 but don't say what they do.

Notes: newer versions of both these chargers have lithium options: mine do not.

I know the best option is to buy the right kit. However, we go away for a long trip on Friday so I cannot buy the right kit before we go, and at maybe £300 for the DC / DC and £150 for the mains charger, I'm a bit reluctant.

Hi, I'm in a similar position as you as my moho came with AGM starter and leisure batteries along with the NE287 BC and NE325 B2B charger. My mppt controller also has a lithium setting. I have been considering replacing the leisure battery with a Roamer 230A LifePO4 battery and I've emailed them today to ask their advice about my setup. I'll let you know what they say or have you already changed over the BC, B2B etc? If you have retained your original system, how is it working? And, regarding the NE325, did you manage to establish what the dipswitches settings were? Thanks, Paul

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[SMB]

I've just received a message back from Steve at Roamer, here's what he said:

"Hi Paul, yes the pb-lead acid setting for the NE287 is usually best…. This provides a charge voltage up to 14.4V with float voltage of 13.5V. Note, it is very important that you remove the temp sensor cable and have EBC disabled. This stops the temperature compensation and desulphation modes which will increase voltage and could potentially damage the battery. The 14.4V setting is a little high but as you say you do not use campsites very often this its totally fine, the BMS will protect the cells from overcharging and the Active Balancing will maintain perfect cell balance.



No problem leaving the AGM starter in place but I would upgrade the MPPT to a Victron Smartsolar. You shouldn’t charge both batteries together so this will be used purely for the leisure battery. The Carbest LiFePO4 profile also isn’t ideal for LiFePO4 batteries. Ridiculous I know but that’s how it is. Theres two reasons for this:



Charge voltage of 14.6V and float voltage of 13.6V are too high, there is no benefit to charging above 14.2V and you risk shortening the life of the batteries by doing so. There is also no need to float at 13.6V, you can disable this mode completely if you want or do what Victron do and have it at 13.5V or lower. The benefit of the trickle charger (maintain batteries over winter) doesn’t apply anyway as best practise is to isolate your lithium battery when not in use.
Neither the NE287 or the Carbest MPPT will be able to ‘wake up’ a lithium battery that is in low voltage protection mode (run flat). So you need at least (proper) lithium charger to do this.


The Victron Smartsolar MPPT allows you to dial in exact voltage settings (although their default LiFePO4 profile is actually ideal). It will also wake up the battery if it runs flat. Its pretty cost effective, the 75/15 (15A) version is about £100 and can be swapped straight in to replace the Carbest.



So basically – leave the NE287 in place but swap to lead acid mode and disable EBC and temp compensation. Swap the Carbest MPPT for a Victron, using the same cables"

I had to read it a couple of times as I'm by no stretch of the imagination handy with stuff like this, hope it's of use to you.

 

[Ava the Adria]

I've replaced my 150Ah AGM with two 100Ah lithium batteries.

The mains charger has options for Pb flooded, Pb flooded with EBC enabled, gel, desulf or AGM. The DC/DC has dip switches S and S2 but don't say what they do.

Notes: newer versions of both these chargers have lithium options: mine do not.

To avoid the over/under voltage issues mentioned in replies above, we simply unplugged the mains from our Nordeletronica NE237 (perhaps a little older than yours), to disable the charger. It has no Lithium settings either. Perhaps because the NE built in mains charger was running flat out all the time to charge the LiFePo's, it seemed noisy and to be overheating and stressing the whole unit leading to issues with (of all things) the running lights/side marker lights intermittently failing. (Their relay is situated inside the NE237).
We then used the now redundant power lead to power a Victron IP22 unit for the LiFePos which we situated next to the NE2337. This runs quieter and cooler than the NE237 mains charger and the real bonus is the batteries are charged fully when on EHU and thus last longer off grid. Whilst there was an additional cost for the IP22, the benefits are well worth it and I no longer stress about melting the innards of the NE237!
Edit, we also downrated the DC to DC to 30A, to also reduce the power going through the NE237 when the engine running. Much cooler running now. You're right, there's no escaping - you do need the right kit!