Cheap charger for "manual" emergency charging? Please read first post.

[Franziska]

Hi,



we have an 840Ah 12V LiFePo4 battery bank.
Usually it's charged with 1200w Solar.



On very few occasions we want to load it by shore power or our 3000W genset.

So far we have used our old Dometic/Waeco MCA 1250 charger for it.
As this is not a charger meant for Lithium it stops charging before the battery is full.



I'm looking for a budget charger which we can use for topping up manually.
This means we interrupt the charge process by hand when the SOC indicator is close to 100%.
Im not looking for anything automatic with a lot of settings and sensors.
We use this only rarely.



I found this one, and yes, we would change the cables of it to a higher crossection:


https://www.amazon.it/30A-caricabatt...A1X7AIKVIB74T9


Would this work? It's available locally and has a reasonable price tag. Will it work better for us then the old Waeco?

[Avionics_Joe]

Yes, but running a 3000-watt gen to get 400 watts of charging doesn't make sense to me, but you of course would also use the Waeco MCA 1250 charger to get 80 amps total.
Depending on when the Waeco MCA 1250 charger shuts off it could be a long time to top off the bank.

[SaylorMade]

You can use any charger(actually just a power supply) that delivers 14,6V.
With LifePo4 systems, the BMS in the battery will take care of the monitoring.
No need to cut off manually.

[GordMay]

Originally Posted by SaylorMade

You can use any charger(actually just a power supply) that delivers 14,6V.
With LifePo4 systems, the BMS in the battery will take care of the monitoring.
No need to cut off manually.

The WAECO PerfectCharge MCA 1250 is a 6-stage IU0U automatic loader with 50 A charge current.
Final charge voltage: 14.4 to 14.7 volts DC
Trickle charge voltage: 13.8 volts DC
➥ https://js-maritimshop.de/Electric-E...ml?language=en

Manual ➥ https://www.manua.ls/dometic/perfect...ca-1225/manual

Or ➥ https://www.manuals.ca/waeco/perfect...mca1250/manual

[more]

https://verkauf-bochum.de/products/b...origin=uzirbsg
Blue Smart IP22 Ladegerät 15/30A lifepo4 charger.
if need more A buy 2-3-4 10

[Tin Tin]

See if you can find the manual for this charger. It may state that is only suitable for certain size batteries.

[BjarneK]

You could consider this: https://www.digikey.com/en/products/...750-15/7706355

Note that this is the 15 V nominal model, which has an output range of 13.5 to 16.5 V which should be good for charging.

You can also get it at TME: https://www.tme.eu/en/details/rsp-75...ies/mean-well/

I have not used it myself, but the specifications look good. It is constant current limited, which is necessary when using a power supply for charging batteries.

Also, it is made to be built in to another product, so make sure to protect the A/C input wires so there is no risk of getting an electrical shock.

[CaptainRivet]

Suggest to get this vevor inverter/charger combo:
https://m.vevor.de/niederfrequenz-we...p_010340279905
For 300 Euro you get a low frequency inverter means 3000W cont and 9kw peak means it starts all also an portable AC and you get 75A charge even with a lithium setting.
Cannot get anywhere cheaper 75A charge, that also works better with your genny. And that inverter is a real beast, installed it 3 times already, my budget goto inverter/charger combo. The AC output is surprisingly clean and nice sinus curve for low frequency in the below 500Euro price class. Hardly have any manufacturer left building low frequency as you simply need beefy and therefor expensive parts but the peak surge capability of 300% means they have no issues with surges like microwaves or induction cooktop have and which kill the cheap HF inverters mosfets.

All the seperate charger lack a proper power supply or are expensive for lithium.
the low frequency inverter just works in reverse mode as charger, means you basically get the charger for free in this design with a proper power supply that’s needed for the inverter part.
That why you always get these as combo inverter&charger as they can ask for the charger function some additional money, vevor strangewise not and literally hiding it.

[NorthCoastJoe]

I got one of these and have never used it yet, got it for the same reason you need one.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[gwalker]

I personally would only ever purchase a quality unit, like the Victron. My friend had a cheap inverter on his PH dash and it caught fire, he had 15 seconds to get off the boat, burned to the waterline. Not worth saving a few $$. Your choice.

[CaptainRivet]

Originally Posted by gwalker

I personally would only ever purchase a quality unit, like the Victron. My friend had a cheap inverter on his PH dash and it caught fire, he had 15 seconds to get off the boat, burned to the waterline. Not worth saving a few $$. Your choice.

Well then it was not installed properly.
And yes with the cheap ones i would expect it doesn't have a properly speced internal device fuse and fuse it appropriately, then nothing can happen.
The Vevor LF ones i linked has proper speced internal fuses.

First there is cheap and unbranded or kryptic asian stuff, yes stay away. Then there are good asian branded ones been around for some time that have a reputation like Giandel, Vevor, Edecoa (not all models, google)...Will Prouse is regularly testing some and these i call budget.

Based on my experience and some others that i know we would advise to use Victron, Studer, Schneider, Mastervolt some Xantrex if you are running it 24/7/365 and you depend on it.
If you use it from time a budget one is definitely enough. If running electric galley or AC then a low frequency one as it lives much longer been able to deal with surges and bad cos pi and you get a charger for free.

You can also combine like i done it, a Victron multi 12/3000 that runs 7/24/365 boosted by an edecoa when admiral or i heavly run the all electric galley. Edecoa runs maybe once till twice a week for 20min max, a 3500W inverter on 2300W max or 10A power assist. Started as an experiment 2.5years ago (as the edecoa was installed when i bought the cat, could sell for 100Euro or just use it till it dies) and works flawlessly since 2.5years.
Get a used Multi 1600W (around 350Euro) and boast it with the Vevor LF i linked...140A charge and 4400W @12v inverter power for below 800Euro that is relaible and easly run a full electric galley.

[newhaul]

Originally Posted by Franziska

Hi,



we have an 840Ah 12V LiFePo4 battery bank.
Usually it's charged with 1200w Solar.



On very few occasions we want to load it by shore power or our 3000W genset.

So far we have used our old Dometic/Waeco MCA 1250 charger for it.
As this is not a charger meant for Lithium it stops charging before the battery is full.



I'm looking for a budget charger which we can use for topping up manually.
This means we interrupt the charge process by hand when the SOC indicator is close to 100%.
Im not looking for anything automatic with a lot of settings and sensors.
We use this only rarely.



I found this one, and yes, we would change the cables of it to a higher crossection:


https://www.amazon.it/30A-caricabatt...A1X7AIKVIB74T9


Would this work? It's available locally and has a reasonable price tag. Will it work better for us then the old Waeco?

To bad your on the other side of the planet I would sell you my spare trace 2012 inverter charger. Has full manual adjustment settings from. 1 amp to 120 amp output and fully adjustable voltage as well . Just needs a new digital readout screen . $75 usd and it's yours . Shipping would be real expensive though .

[smacksman]

My experience is they are great to start an engine in an emergency, but only if the engine starts easily. A continuous drain, like topping up a battery bank, might get these chargers oveheating.

[newhaul]

Originally Posted by smacksman

My experience is they are great to start an engine in an emergency, but only if the engine starts easily. A continuous drain, like topping up a battery bank, might get these chargers oveheating.

They are designed to put out the rated amps for ever now o e with a start boost ( I have one with 50 amp start boost) they do have an auto reseting thermal switch that cycles on and off .

[Franziska]

Thanks everybody. Problem solved.



We can keep the old Waeco.



The whole issue turned out to be a little bit like a sailbatten stuck and engaging a winch before properly looking aloft.



When my boyfriend reassembled the battery pack in Monastir, he was trying to get get even better contacts to the busbars and put a stainless washer on the terminals before adding the aluminum busbars.
His reasoning was, well the studs in the battery cells are stainless too.

Turned out it was a very bad idea. Very bad charging. When he remembered these washers and took them off the battery packs charging ability returned to normal.



Weird, but I suspect the washers caused a tiny corrosion layer which reduced connectivity.



We can now even run the desalinator again from the battery, very happy.