Fishing forum > Charge battery with generator when camping

Author Topic: Charge battery with generator when camping

Works great, we do it all summer long. Usually one battery on the charger and one in the boat.

Yup, no problem. Might not provide quite as stable of a charge as a wall socket (but what can you do in the woods). The worst effect may be a slightly shorter battery cycle life. I was given a smoky old 2-stroke Chinese 900W charger that the previous owner used for the same purpose. Mostly sits on a shelf now, but it was free and one day I may need it for a similar purpose. That or bush-blender Margeritas (don't jump on me MrGrey1) .
Fish'n BC

Has anyone tried trickle charging a battery while camping using a solar pannel? Is this feasable?
Fish'n BC

Thanks Mr Grey1, I think I may try that also.

Just think about the draw from a continuous trolling motor, versus the intermittent draw of a camper (occasional light-super low amps, occasional pump-low amps). Then there is the room in the boat. If you are swapping 2 or 3 batteries and getting a lot of time to charge and a lot of sun, then it will do the trick. Otherwise I think you'll end up with a partially charged battery. By all means experiment and report back if you have the time and money. But I think it will fall a little shy of your expectations.

Actually I don't even really drink margaritas, nor have I ever had a manhattan.
Fish'n BC

Well I was thinking more land based solar charging at a camp that doesn't have plug-ins, instead of using a generator.
However, if I had a choice of running a generator on 12' boat or a solar pannel while fishing: I think I would go with the solar The battery booster that MrGrey1 was talking about sounds be a better option to take along in a small boat for emergencies.

Unless you buy a large high watt solar panel you will not be able to charge up a dead battery within a day.

Small panels like the ones from Canada Tire only put out 5 to 15 watts. It would take days/weeks (lol) to fully charge your battery at that rate. A 15 watt panel at full sun will make around 1 amp at 12 volts if you are lucky!

Think of this: A small 10amp shop charger can take many hours to fully charge a larger size deep cycle battery.

The only boats I've ever worked on that have solar panels that can keep up with charging are very large boats with lots of room(and owners with lots of $$$) to mount very large panels on the top. ( A 100w panel may put out 7-8amps on a very sunny day)

beerdrinker get one of these!

The gel batteries are not worth the price really..
They don't seem to last longer.
I've seen many burnt out within a year or two.(guessing that they can not take a high amp charge. This may dry out the cells or something. Not really sure...)Just know people always seem to be upset with them.

If you take care of a plane old marine battery it will last you many years. Just make sure you have the right type of battery for your needs. You do not want a deep cycle for starting your boat, same as a starting battery will not last if you use it for your trolling motor, high powered systems, down riggers etc etc..

Basic care: Keep the battery clean, charged up, fluid level topped up, don't let it freeze, and do not over change it!

Getting that deja-vu feeling again. If you guys search a bit, I am pretty sure I have contributed to at least 2 threads that painstakingly covered almost all things about batteries and charging...

Those that are claiming that the solar panel is woefully underpowered to use for a "charge" are correct. A panel is to compensate for some of the intermittent low-draw power that is gradually consumed. They are not able to fully "charge" a high capacity battery (that has experienced and extended high-amperage drain) within a reasonable amount of time. It is just simple math really. If you have a decent panel that puts our 1AH (1 amp per hour) and your battery is 800 Amps. That will take at least 800 hours to charge. So that is 34 days of good quality sunlight, of those days we only get about 12-16 hours of viable light (so lets be generous and call it 14 hours). So if you follow the math, it will only take about 2 months or so to charge one battery. I would surmise that you were not planning to be camping that long and might require a more expedient charging solution.

These concepts also demonstrate why we are not all driving flying solar-electric cars yet, quite thoroughly.
Fish'n BC

Catch; would it be safe to say a canadian tire 30 watt (2.5A) 2 pannel solar kit would be equal in charge speed to the 2A trickle charger that Beerdrinker_Few was talking about? Or the 60 watt (5A) 3 pannel kit would charge at about double the speed of the 2A trickle charger? Sounds like the lower amp charge would be better for gel batteries.
The double pannel system is only $250 and the tripple pannel is $400 (plus what ever accessories you would need). I think thse prices would be well worth avoiding the gas, exhaust and noise of a generator.
BTW; I saw a TV shot of a small (12'?)boat with a large solar pannel mounted over the boat motor aft of the stern. It didn't seem to interfer with anything, didn't indicate what it was powering...hmmmmm... but still thinking of land based solar charging while using a second battery out on the water.
Fish'n BC

chakaraka: if your charging logic is correct, why would you be charging a battery for 400 hours with a generator and 2A trickle charger?

This website has a great example in it (math included) of why solar panels don't work for the short term charge you'd need on a camping weekend.
Fish'n BC

That web site was using a tiny .35A peak solar pannel, we were talking about a 2-4 amp solar pannel kits that would be equivalent to a generator and 2 amp trickle charger that Beerdrinker_Few has. Thats 6-12 times the power.
The web site also gives a good argument for using an outboard instead of a trolling motor. I made trolling trim tabs for my boat, so might nix the idea of a trolling motor altogether.

If you know it works, go buy one and show us some pictures of your set up. I'd use one if it was proven to work.
Fish'n BC

LOL, ok I'm certainly no expert on the topic , but logic indicated we seemed to be missing something. Otherwise it would have taken about 400 hours to charge an 800 A hour battery with a 2A trickle charger. I did some research on the matter and it indicated that assuming we needed 100 A hours of charging for a 100 A hour battery is all wrong.

It seems the battery only uses a full current draw for the first couple hours of charging then tapers off to almost no current draw. The remaining charge relies almost entirely on constant voltage to charge.
The amount of current required for the initial part of the charge depends on temperature and type of charge (eg: trickle charge or rapid charge)and doesn't seem to draw that many amps. So as long as you have a constant voltage of 12 volts: the bulk of the charging should be done in a day or so regardless of the amperage.

So the battery doesn't store the amperage induced on it: instead it uses the amperage and voltage initialy then mostly just the voltage to induce then maintain the reaction in the battery cells to charge the battery. Exactly how long a 2A solar charger would take to charge a given deep cycle boat battery remains to be seen (the rating on the solar pannels mentioned seems to be a little high from actual output), but I would think it would be the same as a 2A trickle charger. If I set one up I'll certainly post pictures.

Okay aspiring Tesla's and other naysayers. I agree I was tired and typing fast and my math was flawed. Mostly because I was thinking of CCA, not Ah. What you are missing is Watt's Law. This law reads as such: W = V x A. So using this formula we can see that your wife's 1600W blow dryer in a 120V socket requires a 15 A (13.333) breaker or you'll be constantly tripping it.

The other thing you are missing is that solar panels are not rated in amps, but in Watts. So your 15WATT solar panel puts out 1.15 amps during absolutely perfect light conditions. Whereas a 10 amp charger will put out about 140 watts and a 2 amp about 28 watts. Your solar panel will only make 1 amp for about 1 hour or so during totally sunny conditions, the rest of the time it will provide less than 1 amp. Going by the reviews on it, it never makes more than 500 mA or 1/2 amp even during optimal conditions.

So let's use a 100 Ah deep cycle battery as our new example:

First we need to note that your battery will rarely be completely discharged (0 volts). But you would likely call it "dead" at about 8 volts.

So with your Solar panel, if it lasts long enough to even get the job done, it will take around 300 hours (at 333 mA) to charge a discharged battery (that is IF it can achieve 12.5V or more for that whole time). Or if we use a realistic level of discharge it would take probably 100 or so hours. Now realize that if your solar panel cannot make at least 12.5 volts, then it will not be charging anything.

Now with my charger on low (2 A), it will take me just over 48 hours. This is the advised way to charge the battery and ensure it retains it longest possible lifespan. Or realistically, probably 16 hours at worst.

But with my charger on high (10 A), I can have a completely discharged battery charged in about 10 hours. Now with a 1/3 discharged battery, realistically we are probably looking at a 2-3 hour charge time. But for a deep cycle battery, this can be too quick of a charge and result in lower battery lifespan.

So take your choice:

4-5 days with a Solar Panel (if it even achieves enough output to EVER charge the battery properly).

16 hours or less with a "trickle charger".

2-3 hours on a high amperage charge.
(Most automotive alternators put out way more power than this, so this is perfectly safe for a top-up charge on a "starting battery").

I'm no rocket scientist, just a lowly mechanic who was engaged to a marine electrician for a decade...hope this clears a few mysteries up. Granted this is the simplified "Reader's Digest" version, I think it still illustrates the point here.
Fish'n BC

Chaka your post defies logic.

Firstly, I'm not using the solar pannels to run anything.

Secondly, I'm looking at the 30 watt pannel kit that is rated at 2 amps and the 60 watt pannel kit that is rated at 4 amps...not the 15 watt pannel.

Now you admit that your 2 amp charger puts out 28 watts and charges your battery in 16 hours. Well why wouldn't the 2 watt solar charger puting out 30 watts also charge your battery in 16 hours (sunlight permitting)? It's the same thing!

If the solar pannel took days then your charger with the same amperage and same wattage output would also take days...but you admit it takes only 16 hours (although you also mention 48 hours for some reason). If you are concerned about the 30 watt pannel kit being I already mentioned in my last post...then get the 60 watt pannel for $150 more. Your 10 amp charger will likely kill a deep cycle/gel battery, so fast 10 hour charges are redundant in this case.
Fish'n BC

Correction: where I said 2 watt charger...I meant 2 amp charger.

Chris, if you say so. Until you put your money where your mouth is, this is all conjecture.

I charge batteries nearly every day and have metered many batteries and the 4 chargers we own in our shop. Show me a metre on your cheap offshore manufactured solar panel with overstated output and durabilty problems please. Do your research or SHOW contradictory results. You could also try reading the whole post. Right in there I explain that a completely discharged battery would take 48 hours at 2A but that we do not discharge batteries to 0V. So a battery at say 8V and declared "dead" would be maybe 12-16 hours...this was based on a 100Ah battery and is not voodoo, just simple math.

From what I gather, these panels are so poorly made that they crap out and never put out their claimed power. So go grab your 60W panel and show me it making 15V @ won't ever.

Fishing forum > Charge battery with generator when camping


Home | Sign Up | Contact Us | Forum | Forum Policy | Site Map
Disclaimer: All information on this site, including depth charts,
maps, directions are not intended for navigational use.
Copyright 2003-2018 All rights reserved.

is now FREE!
View All Submit New

To submit new report:

1. Select fishing spot from
Trip Planner

2. Submit new report

Elbow Lake
Fishing: Good
Catch: 20 Rainbow Trout
Sun, Jul 08, 2018
Echo Lake (Vernon)
Fishing: Good
Catch: 4 Rainbow Trout
Wed, May 23, 2018
Hayward Lake - North
Fishing: Excellent
Catch: 5 Rainbow Trout
Mon, May 21, 2018
Hayward Lake - North
Fishing: Moderate
Catch: 3 Pikeminnow
Mon, May 21, 2018
Chilliwack Lake - North
Fishing: Difficult
Catch: 2 Rainbow Trout
Mon, May 21, 2018
Hayward Lake - North
Fishing: Good
Catch: 10 Whitefish
Tue, May 15, 2018
Kalamalka Lake - Kekuli Bai
Fishing: Good
Catch: 3 Kokanee
Sat, May 12, 2018
Mill Lake
Fishing: Moderate
Catch: 2 Rainbow Trout
Sun, Apr 15, 2018