no sun, how do you manage

[Dean1]

I just did 5 nights with a 200 watt panel and 220AH of batteries with a 95ltr waeco. Managed to stay above 12v but the last night batteries went under 12v and waeco switched off to low voltage.
I read it was bad to let batteries go under 11.8v??
We were putting hot stuff in the freezer which sucked the charge up.
Been trying to get batteries charged back up with minimal light at home and have only gone from 12v to 12.4v in 2 days with no load. Lucky we had good light on those 5 days!

[Dignity]

Why not install it under the bonnet or in the back of the Colorado. Then it will charge as you drive automatically or you can have it hooked up to the solar. All you would need to add is an isolator to save your starter battery from going flat. 11.2volts is almost completely flat. If you checked your battery after 3 hours driving and it was showing 12.7v then I think you were reading the surface charge, you need to leave it sit for half an hour or so to let the surface charge dissipate to get the true voltage of the battery

This is a table I use to keep tabs on things with my batteries, its not perfect but a pretty good indicator



Cheers.

Nomad, I put the battery on charge when i got home last Tuesday week, its a 10 amp charger and has a setting for a deep cycle gel battery, it took most of the day. I just checked it this afternoon and it is still showing a charge of 13.06 V, which is probably closer to its full capacity.

[Dignity]

I just did 5 nights with a 200 watt panel and 220AH of batteries with a 95ltr waeco. Managed to stay above 12v but the last night batteries went under 12v and waeco switched off to low voltage.
I read it was bad to let batteries go under 11.8v??
We were putting hot stuff in the freezer which sucked the charge up.
Been trying to get batteries charged back up with minimal light at home and have only gone from 12v to 12.4v in 2 days with no load. Lucky we had good light on those 5 days!

Dean, with deep cycle I dont think it is as bad as with CCA batteries or in pzrticular calcium batteries. My knowledge is limited but I suspect your solar panel might struggle a bit if it is an AGM type as they usually need a hefty boost to get them going. Maybe ive misunderstood it but from what ive read is that the best charge rate for a battery is one that can put in around 10% of the batteries capacity.
PS. Lack of sun is what led to my dilema.

[Dean1]

Hi Dignity, yes i think you are right. I experimented alot with a multimeter, angling the panel directly into the sun made a huge difference as well! I found i got more charge in one hour if panel was facing direclty at the sun, versus 5 hours angled to the sun. And the panel needs to be completely in the sun (no shade) made a huge difference. Also make sure there is no dust on the panels as mine were dusty and my camper next to us wiped it clean it started charging instantly!! Keep the panels clean!
Was my first time with solar and i learnt alot!

[NomadNoosa]

Nomad, I put the battery on charge when i got home last Tuesday week, its a 10 amp charger and has a setting for a deep cycle gel battery, it took most of the day. I just checked it this afternoon and it is still showing a charge of 13.06 V, which is probably closer to its full capacity.

Thats good Dignity. An AGM battery likes to charge at 14.4v, not much higher, I think a gel likes to charge at a lower rate, about 14.1v I think from memory. It don't know what type of charger your using but most of the newer ones go through a bulk, absorbtion and float stage to get the battery to 100%.

At full charge of float it will show around 13.7v. It will reduce if the charger is disconnected and the battery is let sit for a while, sometime a few days. Then it will decrease to around 12.7v. This is 100% charged. the amount above 12.7v is known as the surface charge.

The longer a battery sits the more this surface charges absorbs into the lead plates and the better charge you actually have.

So when your away camping or boating yep get as many amps into the battery as you can. When you get home the best way to charge your battery is slowly.
I run a 25amp projecta at home that has various amperage setting, 2amps, 6amps, 12amps and 25amps. When I have the time I charge at 2amps and this can take a few days to get the batteries to full again but it is a slower deeper charge.

Dean, with deep cycle I dont think it is as bad as with CCA batteries or in pzrticular calcium batteries. My knowledge is limited but I suspect your solar panel might struggle a bit if it is an AGM type as they usually need a hefty boost to get them going. Maybe ive misunderstood it but from what ive read is that the best charge rate for a battery is one that can put in around 10% of the batteries capacity.
PS. Lack of sun is what led to my dilema.

Calcium batteries like a higher charge rate, 14.7v, so thats why with solar its particularly important to have the regulator at the battery, to reduce voltage drop or to have heavy cables. Most panels that come from SCA or Ebay etc generally have cheap regulators attached to the back of them so it can be useful to bypass them and buy a quality regulator and wire it directly to the battery and run cable direct from the panel to that.

Theres no right or wrong with electricery.........just ways to try and maximise what you've got to be able to stay out longer.

Cheers Nomad.

[Dean1]

Hi Nomad, thanks for the reply. Yes i have installed a Victron controller in the box were my batteries are stored with a short cable running from it to the batteries. I have a projecta charger as well. Is it better to use a 240v charger to get batteries back up to full charge or is solar ok as well? Is it the same in other words? Obviously solar takes longer but is it as effective?
Cheers

[NomadNoosa]

Hey Dean,

Either or..........A good regulator like the Victron won't overcharge your batteries.

Regards

[Bremic]

I can understand the no generator rule, but in the situation described, would running it for a few hours in the middle of the day be such a bad thing? Different to running it day and night. A little 4 stroke generator would be less intrusive than idling the Patrol for a couple of hours, to achieve the same thing.