10W solar panel on a 50Ah cranking battery Regulator needed?

[Avocet]

Hi All,

"Asking for a friend"... (no, really)!

He has a 50Ah cranking battery and a 110 Ah leisure battery. He was going to get a couple of 10W solar panels and leave one connected to each battery over the winter to keep them topped up. I think the leisure battery will be fine with that, but was wondering about the smaller cranking battery. Would that be OK with a 10W panel permanently connected, or does he need a regulator too?

 

[garymalmgren]

Winter= not much sun.
10 watts = not many watts.
No need for a regulator.

However they (non MPPT type) are very cheap, so why not fit them?
You get USB outlets built into the regulator

PWM Solarregler 12V/24V Auto. 30A20A10A LCD Batterie PV Zelle Panel Ladegerät Regler Lampe 100W 200W 300W 400W 500W - AliExpress 13

 

[William_H]

Far more reliability without a regulator. Just hook it up. Fuse at the battery end of wiring. ole'will

 

[VicS]

Hi All,

"Asking for a friend"... (no, really)!

He has a 50Ah cranking battery and a 110 Ah leisure battery. He was going to get a couple of 10W solar panels and leave one connected to each battery over the winter to keep them topped up. I think the leisure battery will be fine with that, but was wondering about the smaller cranking battery. Would that be OK with a 10W panel permanently connected, or does he need a regulator too?

There are a couple of "rules of thumb" regarding this.

If the size of the panel , in watts, exceeds 10% of the battery capacity, in Ah, a regulator is required.​

​

Panels over 10 watts should always have a regulator.​

On this basis the 50 Ah battery/10 watt panel combination should have a regulator but in wintertime probably not necessary.
I have found that a 5 watt panel will easily keep a small battery charged without needing a regulator.

 

[Neeves]

Hi All,

"Asking for a friend"... (no, really)!

This sentence, or one like it, is posted every so often, or at least occasionally

Why do people ask a mate to pose the question on their behalf. Joining YBW is free, its easy to join, unless you are banned. The forum benefits from a varied membership and depends on people, with diverse views, to contribute. If you run a commercial activity in conflict with Forum rules - you need to be discrete.

So....why?

Jonathan