Hi.  This battery was suggested as a replacement for my current set of Enertec batteries(2x 100ah). Are they any good?

Batteries connected to what? I don't know Rentech LFP's but that's neither here nor there, the equipment drawing power from the battery needs to understand and be able to use a LFP battery with BMS and the same goes for the unit charging the battery. What are your current SLA's connected to?

HI Kalahari.

I have a 3Kva Mecer inverter, with a builtin 600wMPPT controller, and 3x 200W Poly solar panels.

The proposed replacement battery is a Rentech 25.6V 100Ah Rack-Mounted Lithium-Ion Battery - (2.56kWh) with Battery Management System

Ok on the Mecer, again, an item I don't really know, I would talk to the source of the inverter/read the manual about running it with a LFP battery, it should be doable, but may not be ideal, if it cannot talk to the LFP batteries' BMS.

On some inverters some suggestions are made about settings for charge and float voltages to run LFP batteries, but this is less than ideal, either way, a 100Ah LFP would allow more power to be taken from the battery than what your presumably SLA's would allow and the LFP could probably handle a discharge depth of 80% whereas the SLA's would even at 50% do not so well...

Edited February 23, 20224 yr by Kalahari Meerkat

10 hours ago, Kalahari Meerkat said:

Ok on the Mecer, again, an item I don't really know, I would talk to the source of the inverter/read the manual about running it with a LFP battery, it should be doable, but may not be ideal, if it cannot talk to the LFP batteries' BMS.

On some inverters some suggestions are made about settings for charge and float voltages to run LFP batteries, but this is less than ideal, either way, a 100Ah LFP would allow more power to be taken from the battery than what your presumably SLA's would allow and the LFP could probably handle a discharge depth of 80% whereas the SLA's would even at 50% do not so well...

I see. Thanks. I shall do that. Have you heard of this brand, by the way, or know much about it?

 

Edited February 24, 20224 yr by Sagren

12 minutes ago, Sagren said:

Have you heard of this brand, by the way, or know much about it?

I have not heard of Rentech before, so can't really say, I suspect they, like many others locally, are getting cells, BMS and probably even the chassis from outer Mongolia and after putting it together, sticking their name on it. If they are using decent quality components, they are probably no worse and no better than any of the other suppliers/"manufacturers".

As for your inverter @Coulomb may be able to shed some light on whether it would support LFP batteries properly.

 

3 hours ago, Kalahari Meerkat said:

I have not heard of Rentech before, so can't really say, I suspect they, like many others locally, are getting cells, BMS and probably even the chassis from outer Mongolia and after putting it together, sticking their name on it. If they are using decent quality components, they are probably no worse and no better than any of the other suppliers/"manufacturers".

As for your inverter @Coulomb may be able to shed some light on whether it would support LFP batteries properly.

 

Thanks, Kalahari.

On 2022/02/24 at 4:22 PM, Kalahari Meerkat said:

As for your inverter @Coulomb may be able to shed some light on whether it would support LFP batteries properly.

All I saw was "3 kVA Mecer inverter". I think only the 5 kVA models have direct support for lithium batteries. The latest display firmware (which talks to the BMS) handle a variety of protocols, but I don't know what protocol this Rentech battery might use.

And of course, there is no patched firmware for 3 kVA models, so no LFP tweaks.

2 minutes ago, Coulomb said:

All I saw was "3 kVA Mecer inverter". I think only the 5 kVA models have direct support for lithium batteries. The latest display firmware (which talks to the BMS) handle a variety of protocols, but I don't know what protocol this Rentech battery might use.

And of course, there is no patched firmware for 3 kVA models, so no LFP tweaks.

Hi,

I have a Mecer 3kVa with a builtin 600W MPPT and 3x 200W poly panels. They were initially attached to 2x100Ah Oliter Gels, which failed within the first year. They were replaced with Enertec. My installer suggested this as a replacement. I have attached a picture of my installation as well

 

Rentech-24V-Rack-Mounted-Li-ion-Battery-v4.pdf

Lithium batteries are generally a considerably better long term investment than lead acid.

Those Rentech batteries are not a well known brand. Being restricted to 10 or 20 A of recharge current has me puzzled; that's only 250 or 500 W. But I guess 500 W is a reasonable match for your very small system.

I would just be concerned about support in 5-10 years when Rentech might be a footnote in solar history. I don't know the South African market, maybe they're a huge brand that's been around for ever.

15 minutes ago, Coulomb said:

Lithium batteries are generally a considerably better long term investment than lead acid.

Those Rentech batteries are not a well known brand. Being restricted to 10 or 20 A of recharge current has me puzzled; that's only 250 or 500 W. But I guess 500 W is a reasonable match for your very small system.

I would just be concerned about support in 5-10 years when Rentech might be a footnote in solar history. I don't know the South African market, maybe they're a huge brand that's been around for ever.

I haven't either.

I have a lot to learn here.

Thanks Coulomb.