the never ending question

[desert_sailing]

I have scoured the forums.. youtube..manufacturers sites.. etc.. regarding solar.

The one thing that makes it most confusing.. and I see I am not the only one.. is that they all start with the "how much do you need" basis.

I think many.. myself included see the NEED part as how much can I afford. For me that is pretty much a 100 watt starter system. I understand that I  am likely going to have to reduce my energy needs..and that is fine. I do not plan to have much going on. A strip of dimmable LED going down center.. charging phone/ipad.. and occasionally tv... tho I usually watch stuff on a device instead of tv.

Thats it..nothing else..no fridge at this time.. ac.. micro.. blah blah blah..etc etc etc.

Can someone please tell me what battery (non Li) that I should use with a 100 watt suitcase panel?... I see the dif types.. like type24?..and info on discharge rate.. c8..c10..c20..etc etc. how many amps.. the type and discharge rate would be usefull... I am assuming 4 hours of good sun a day...

I appreciate your time and thank you in advance for answering this eternal question.

It would be nice if there were a chart that showed what common solar setups provided and let a consumer choose from there. I get it the industry would rather sell you an additional panel than for you to reduce your usage.. I however am looking for a basic energy plan and adjust my usage to meet that... I will upgrade once I know I would need to.

I am a frugal basic sort... I am into..minus minus minus.. and the industry is add add add...:/ go figure

 

[B and C]

You are talking about a lead acid (LA) battery most likely since no Lion. There are two main types of LA, AGM (absorbed glass mat non spillable) and a wet cell battery that you will have to monitor water levels and add distilled water to on a regular basis.

Then there are two types of these batteries, engine stating usually expressed in CCA (cold cranking amps) and deep cycle batteries that have a 20 hour discharge rate expressed in amp hours (AH). Either the agm or wet cell battery in a deep cycle type is what you are after. These can only be discharged to 50% of the 20 hour capacity. Example; a 100 AH deep cycle battery only has about 50 AH of usable capacity before the battery will degrade quicker.

All you have to do then is see how much power your devices consume @ 12VDC and add the number of hours each will be using 12VDC. That number will give you the minimum sized deep cycle battery you need. If you throw an inverter in the mix to use your devices, add about a 20% loss of capacity. These are all rough numbers.

Your reference to a type 24 battery refers to the case dimensions, not its' capacity. Check the 20 AR rating.

You should buy device chargers made for car recharging (car charger) to get rid of a need for an inverter.

I have an inverter in my van but it has only been turned on one time so I could supply 120VAC over a long extension cord to another vanner that didn't have a way to charge/run their devices off 12VDC.

Wow! Long post for me being a two finger typist.

 

[user 423]

My system is a 100 watt Renogy with one 105ah flooded battery. The main power draw has been a small 45 watt fridge but also charging phone,tablet,laptop. Lights have been all AAA powered push lights but I'm adding 12V LEDs now.

Mostly no problem except for a couple of 3 day or so rainy periods (April to Nov.last year). I have a small 900w generator to power my charger but I've only used it about 4 times in that period.

A flooded battery is more to mess with and if I did it over again, I would definitely go AGM. I'm now in the process of adding a UB121000 AGM 100ah ($179 on Amazon). It will be hooked up separately from the FLA battery and hooked up to an 80W portable panel.

With 2 batteries and 2 panels, I'm hoping not to need the generator.

 

[desert_sailing]

My system is a 100 watt Renogy with one 105ah flooded battery. The main power draw has been a small 45 watt fridge but also charging phone,tablet,laptop. Lights have been all AAA powered push lights but I'm adding 12V LEDs now.

Mostly no problem except for a couple of 3 day or so rainy periods (April to Nov.last year).

A flooded battery is more to mess with and if I did it over again, I would definitely go AGM.  I'm now in the process of adding a UB121000 AGM 100ah ($179 on Amazon).  It will be hooked up separately from the FLA battery.

Thanks for the post!.. I was thinking a 100ah agm... wasnt sure if that was too much for the 100 watt panel. Thanks for posting the battery along with a price and where to find one. I was also thinking of just getting some battery strip or push lights.. maybe ill just get those for back up in case i burn my energy too fast. It sounds like my occassional tv usage would be less than your using of a fridge.. seems like I wont have much problem.. supplying my needs.

Thanks Brian for the additonal clarity on the types and discharge rates!

oops... i posted this 2x it seems...

 

[Trebor English]

I got a trolling motor battery. It's a group size 24 flooded battery, 75 amp hour, $80. Sam's has several Duracell flooded batteries that size. Of the bunch this one is the highest amp hour rating and the lowest cold cranking amps rating.

I use it with a 100 watt solar panel and a cheap $11 PWM charge controller that actually charge at about 5.5 amps max. I have the charge controller voltage set to 14.4 volts. It holds that voltage until the sun goes down. If I am going to be away from the van I drop that to 14.

The common advice is to only discharge 50% of the battery capacity. Since this is not a pair of golf cart batteries or an industrial fork lift battery I have been making it a point to only discharge 25%. So presuming that it is only 60 amp hours now I don't go past 15 amp hours, usually more like 5.

As to discharge rate I use it as the van starter battery so that's a couple of hundred amps for a few seconds. When my inverter turns on there is a huge very short 60 amp surge. Otherwise the limit is about 6 amps.

It uses about 20 ml of water per cell per month. A lead / antimony plate alloy used in deep cycle batteries causes this. Lead / calcium alloy starter batteries use very little water but die quickly with 10% discharge or more cycling. Running it out of water is like running an engine out of oil.

https://www.samsclub.com/p/duracell-marine-battery-group-size-24dcc/prod3590221?sr=24dcc

 

[user 423]

It sounds like my occassional tv usage would be less than your using of a fridge.. seems like I wont have much problem.. supplying my needs.

How big is the TV and how much power does it use?  Mine is a 19" that draws 2.5 amps. 

To run down the batt to 50% would take about 20 hours of continuous use.

 

[desert_sailing]

I don't actually have a tv now., (loaner atm)...Just assumed I probably would pick up a small one.. 19" or whatever is basic and cheap.

Good to know that your tv can run that long...at about 2 hrs a day for me ... that would be about 10 days!