Can I charge solar batteries in a regular charger

[Getaway]

I have four 12v 115AH Expedition Plus AGM Deep Cycle Leisure Battery in parallel connected to 600w solar panels I would like to know can a regular battery charger be use to top these batteries when the sky is overcast I would appreciate any advice on what type of battery charger do I need to use I'm not sure what spec to look for regarding the maximum amperage of a charger the faster the batteries can be charged will be preferable if that's possible

 

[sunshine_eggo]

Yes. With 115Ah * 4 = 460Ah of capacity, you need to be charging at around 46A (10% of capacity or 0.1C). If your battery specs allow higher charging, you can go higher. AGM typically accept higher charge currents than flooded, so 92A might work. Might also be easier to round up to 100A.

I have three of these:

PM4 Series - PowerMax Converters in 12, 24 & 48 Volts

AC to DC Power Converters can be used for RV Converters, Car Audio Power Supplies and any Battery Charging for 12, 24 & 48V systems

powermaxconverters.com

2X 100A units and a 55A unit.

For high current charging, these are often the most cost effective.

 

[mikefitz]

At the 20 hour rate, the normal rate for capacity value, the batteries are 106 Ah.
You need to use a charge current of 0.2C, 20 amps per battery, with a long absorbtion time and a 14.7 absorbtion voltage. Float at 13.7 volts.
Charging at a lower current may reduce battery service life. Your solar is somewhat low.

You have the additional problem of a long charge time even at the maximum solar of 40 amps, the absorbtion period using the Rolls Batteries calculation, T = 0.38 x total capacity / charge current, 0.38 x 424 / 40 = 4 hours.

The usual common problem of inadequate charge current and a short absorbtion period is a gradual walk down of capacity.

Charging fully with an AC charger will help.

Mike

 

[Browneye]

For a high-amp converter charger there is also IOTA with the AGM dongle, or Progressive Dynamics, to consider.
These all seem to work well for LA batteries, for LFP not so much. I finally gave up on getting my Powermax converter to work properly with my lifepo4 battery.

I ran a IOTA with GC2's in the RV for a dozen years and it was just fantastic.

 

[Vigo]

For a high-amp converter charger there is also IOTA with the AGM dongle, or Progressive Dynamics, to consider.
These all seem to work well for LA batteries, for LFP not so much. I finally gave up on getting my Powermax converter to work properly with my lifepo4 battery.

I ran a IOTA with GC2's in the RV for a dozen years and it was just fantastic.

That reminds me i never finished that huge thread.. what went wrong?

 

[Browneye]

That reminds me i never finished that huge thread.. what went wrong?

The auto 2-stage charging setting is not voltage adjustable, and tops out around 14.6V. My pack will get cell runners that reach full when the battery gets to about 14.2 to 14.3. Even carefully balanced at high-knee. So I set the fixed-voltage charge option at 14.1 and shut it off when current got to about 11A - 5% tail current.

After several months I could not get the powermax to sense charge level and actually charge. It would just flash the green led indicator and bounce charge current on and off. If I shut off the SCC sometimes it would work right, but I finally just gave up and bought a Meanwell. It works just dandy. And it's automatic. Set it for gel, it charges to 14.0V, and shuts itself off when current hits 5% (give or take). Perfect. The only downside is that it doesn't self reset - it has to be power-cycled. And it won't terminate charging if there's a load to service. For an RV that's fine, and I have it on a switched outlet so I can manually turn it on or off. I rarely use shorepower or generator for LFP charging - solar keeps it charged up. I would look for another option for a power-wall type application though.

 

[Vigo]

Ok. This is possibly quite relevant to me because i thought when you moved the switch on the side of those things to ‘fixed voltage’ that it stopped trying to do multi-stage charging, wouldnt need to ‘sense’ anything, and would just spit out that voltage without giving any opinions about it.

If it doesnt do that i will probably avoid them.