BajaNomad

Solar car battery charger ???

motoged - 12-4-2015 at 01:45 PM

Nomads,
What recommendations do you have for a portable solar (trickle) charger for deep cycle car/boat battery that won't overload battery that costs under $100?

TIA

woody with a view - 12-4-2015 at 02:26 PM

Solar battery tender junior didn't provide enough juice. Waste of funds.

PaulW - 12-4-2015 at 02:46 PM

Quote: Originally posted by motoged  
Nomads,
What recommendations do you have for a portable solar (trickle) charger for deep cycle car/boat battery that won't overload battery that costs under $100?
TIA

===
You need something around 1.5 Amp. I cannot recommend one . I use the one that came with my 03 VW.
Paul

[Edited on 12-4-2015 by PaulW]

larryC - 12-4-2015 at 05:23 PM

In my garage I have 3- 42 watt panels mounted on the roof and wired to a 10 amp morning star charge controller. I then have wires from the controller to individual batteries in different cars and boats. It keeps them charged pretty well while I am gone during the summer months. YMMV.
Larry

WestyWanderer - 12-4-2015 at 07:51 PM

Quote: Originally posted by motoged  
Nomads,
What recommendations do you have for a portable solar (trickle) charger for deep cycle car/boat battery that won't overload battery that costs under $100?

TIA


I'm assuming you're looking for a maintainer that you can leave on for months at a time while you're away, is that correct?

WestyWanderer - 12-4-2015 at 07:53 PM

If so I have had good luck with this unit:

http://www.amazon.com/Battery-Tender-021-1163-Solar-Maintain...

There are also many different solar panels that are rated for trickle charging but do not have a built in charge controller which means you would have to remember to take if off so you don't overcharge your batteries. These units sell for as little as $20

[Edited on 12-5-2015 by WestyWanderer]

Pacifico - 12-4-2015 at 08:32 PM

Motoged, I just bought a couple of these; one for my boat and one for a trailer I have that has a winch and battery in it.

http://www.solar-electric.com/solar-panels-mounts-kits-acces...

http://www.solar-electric.com/sg-4.html

Be aware there are battery "maintainers" and then there are panels which will actually charge a battery...depends on your application.

battery savers

captkw - 12-4-2015 at 09:14 PM

its down to volts and not about amps for most systems... a float charge of 13.2 is the norm and unless your running a 8D or larger,, amps don't come into the picture....BTW, the fastest way to kill a batt is for it to sit discharged,, which it will do slowly all by itself

motoged - 12-4-2015 at 09:38 PM

Nomads...as initially stated, I am looking for a PORTABLE solar charger that won't overcharge a deep cycle battery.

I will use battery for a CPAP machine when camping...as well as my guitar amp :cool: and want to not spend more than $100.

Some solar chargers won't have a device that stops an overcharge...so some secondary gizmo that measure battery charge level might be a second piece of hardware aside from a simple charger.

I am a total marooon with the concepts of electricity (light bulbs still amaze me)...but I do know that the CPAP has a low amp discharge that is about 8-12 amps used overnight....enough to drain a 5-7 volt moto battery...but I also know the deep cycle car battery runs the CPAP for several sleeps with no real drain....don't know about a 15-20 watt amp yet....

So , a solar charger that kicks out more amps than a usual trickle charger is what I might want...

I am on a learning curve here....:coolup:

landyacht318 - 12-5-2015 at 01:52 AM

8 to 12 AH consumed overnight sounds pretty low for a Cpap.

A 50 watt panel should be able to return that +10% more into the battery to fully recharge it daily.

Unfortunately you are not going to get a kit with a charge controller for under 100$.

If and only if you actually monitor the battery voltage and do not let it get above 15 or so, you might be able to get away without a controller, but I would not recommend it.

http://www.amazon.com/s/ref=nb_sb_noss_1/179-5026990-7376712...

Something like this:

http://www.amazon.com/HQ-Monocrystalline-Bendable-Solar-Pane...

and this:

http://www.amazon.com/Controller-Autoswitch-Intelligent-Regu...

Are about as cheap as you will find.

Do note most 12v wet/flooded lead acid batteries, even if they prominently say deep cycle on them, are more of a dual purpose battery, closer to a starting battery in construction than they are to a true deep cycle battery like a 6v golf cart.

If the Cpap actually does only draw 12AH maximum overnight, then I'd be OK with a 35AH AGM battery, for the portable factor:

http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3D...

It would be a pretty good match with a 50 watt panel aimed at the sun 3 times a day.

captkw - 12-5-2015 at 02:14 AM

For the guitar,, I would get a "Pig Nose" amp...they Rock !! I don't know what the draw of a cpap is ,,but you can find a regulated solar panel for a good price at any decent marine place..and that would not be Worst Marine !!

woody with a view - 12-5-2015 at 06:31 AM

landyacht, what does the "charge" side of this do? panel comes in goes and out to the battery but the "charge?"



41ceTp7Xy8L.jpg - 29kB

TMW - 12-5-2015 at 10:03 AM

Looks like it goes to a light bulb or some type of charge indicator to show it's charging.

Bajazly - 12-5-2015 at 10:41 AM

I got this one earlier this year and while camping out at Animos in May I had my second battery die. I was basically running the ARB straight off the panel. Had to have the dead battery in line and jump start the panel every morning but for 3 days the fridge ran fine.

A little more than a C note I know but when I bought this one in April it was about $325, a little better now and I'm sure it's all you would need for a long time.

Renogy 100 Watts 12 Volts Monocrystalline Foldable Solar Suitcase

http://www.amazon.com/Renogy-Watts-Monocrystalline-Foldable-...

motoged - 12-5-2015 at 11:52 AM

Muchas gracias, amigos......you guys are great for pointing me in a good direction....

For some reason I thought my CPAP drew 1.5 amps/hr.....but, the "electricity" language is still confusing for me.....I will research that further.

I have a few different small amps....the smallest is the size of a toaster (Kustom KGA10 10 watt) and the one with more features is a Line 6 Spider IV 15 watts and is the size of a carry-on suitcase.

I am following up on your suggested links....:light:

landyacht318 - 12-5-2015 at 09:24 PM

Quote: Originally posted by woody with a view  
landyacht, what does the "charge" side of this do? panel comes in goes and out to the battery but the "charge?"



I believe this is a load diversion. When the controller/solar combo has the battery upto absorption voltage, then the amperage needed to hold absorption voltage begins to taper, and these extra amps get turned into waste heat, OR if something is hooked it the terminals on the far right, it can send the extra juice there.

Some choose to wire load diversion to the engine battery to top it off if the charge controller is hooked to an Auxiliary battery. Nothing HAS to be hooked to those terminals.

I am not familiar with that exact controller so can't say for sure.

I'd buy two of those at that price, one as a backup/ barter.

woody with a view - 12-6-2015 at 11:50 AM

my truck had a red top Optima AGM in it. it sites for weeks/months at a time. with infrequent runs around town the battery never really gets a good topping off and wants to rest around 12.3-5v i have this: http://www.amazon.com/Battery-Tender-021-1163-Solar-Maintain... but i believe it doesn't put out enough juice to keep the battery topped at 13.6 or thereabouts.

i'm looking for suggestions for a system to keep the battery topped off. its a year old and gets put on a charger occasionally.

edit: ideally, i'd like to hook a panel to your controller and set the panel on the hood, leaving the controller under the hood clipped to the battery.

[Edited on 12-6-2015 by woody with a view]

landyacht318 - 12-6-2015 at 01:02 PM

AGM batteries can vary widely as to the manufacturer charging recommendations, although they tend to get painted with the same brush by many.

AGMs seem to fall into the + or - 30% category, either they recommend a minimum charging rate when deeply cycled, or a maximum / do not exceed rate.

Even the lesser$$ AGMS which say not to exceed 30 amps per 100AH of capacity benefit from recharge rates upto 30% applied from the most depleted state.

Higher $$ AGM like Odyssey, Lifeline and Northstar have basically no easily achievable upper limit on amperage.

My recommendation on an AGM that seems to be weak, is to discharge it to 12.1 to 12.2v rested, meaning the voltage does not rebound to 12.3+ when the load is removed, then apply a 30% charge rate until 14.4v is reached, then hold 14.4 until a 100AH capacity battery can only accept 0.5 amps.

If a Lifeline, Northstar, or Odyssey, then the higher the amperage, the better, as long as ~14.4v is not exceeded at the battery terminals. (14.7v for Odyssey, at 77f)

Optima's charging instructions make little sense. I have no confidence or respect for optima batteries, but I'd drain it to 50% and give it a high amp recharge and hold absorption voltage 14.4 to 14.8v until the amps required to hold it at absorption taper to 0.5% of capacity.

Trying to top charge a weak AGM is not going to restore capacity. the 50% depletion and high amp recharge stands a much better chance of restoring lost capacity but by no means is a guarantee.

Obviously this requires some special charging equipment, and the battery still might not respond to a high amp 100% recharge.

Vehicular voltage regulators rarely hold the right voltage long enough to actually top off a depleted battery. Expecting a vehicle to 100% fully recharge a depleted battery, is unwise, and the battery will suffer for it.

80 to 100% charged takes about 4 hours minimum, no matter how powerful the charging source might be, so the guy who needs a jumpstart and thinks a drive around the block or 2 is all that is needed, is seriously deluded.

Maintaining any lead acid battery at 100% is always the wisest course of action, but doing so to a sulfated battery is not going to restore lost capacity. The 50% depletion followed immediately by a high amp 100% recharge is likely the most effective method of capacity restoration on an AGM battery, and to a lesser degree on a flooded battery.

While a slow recharge is less abusive to a battery, the heat generated by high amp recharging can help to dissolve the sulfation back into the electrolyte.

Grandpa's trickle charger mindset is mostly wrong. If one has days and days, go for it, but a higher charge rate stands a better chance of returning Specific gravity to its maximum baseline on a chronically undercharged, unhealthy battery.

When the next discharge cycle begins soon, then low and slow trickle chargers make no sense. Better to start a discharge cycle from the highest state of charge possible.

If one is going to hook a maintenance charger to a battery, one should have the battery 100% charged by another charging source first.

woody with a view - 12-6-2015 at 01:16 PM

i just checked it and it's sitting at 11.75 after 3 weeks off the charger. i must have a drain somewhere. i'm going to put it back on the http://www.amazon.com/KeyLine-Chargers-KC-75A-MP-Maintainer-... until tomorrow. i hate to disconnect the battery while the truck sits because the ECU needs to relearn all of the parameters.

landyacht318 - 12-6-2015 at 01:40 PM

That charger is only 0.75 amps. If the battery were healthy and depleted to 11.75, it would take days and days to even approach 90% charged. It depends on the max voltage the charger will seek and if it only ever seeks 13.6v it will likely never be able to fully recharge that battery, as that battery wants to be brought upto at least 14.6v and held there for hours. One day of 0.75 amps is not going to do much at all, besides perhaps tickle the battery to its grave.

11.75v is a very discharged battery. That small maintainer should be left on it while it sits, not used after the battery voltage has dropped to 11.75.

Unhealthy batteries have more self discharge than a healthy battery. 11.75v does not necessarily mean a high parasitic drain, but wireless door locks and alarm systems can fully drain a battery in 3 weeks, or less, on more modern vehicles.

There are some devices that can be used to keep the memory settings of the ECU when the battery is disconnected.

A slow draw down to 11.75v is basically batterycide. Did you get your money's worth from this battery?

It might recover some lost capacity and give some timespan more service if fully charged, but it is like a gas tank which has shrunk from 35 gallons when new, to 7 gallons now.

You can still fill the tank, but you only have 7 gallons.

The higher the state of charge a lead acid battery is stored at, the longer the gas tank remains near that 35 gallon capacity.

It is basically impossible to restretch that 7 gallon tank back up beyond a 10 gallon tank ever again, and 35gallons, is a pipe dream.

In the future, if you still want an AGM, skip the Optima. Go for Odyssey or Northstar. 25% more capacity, nearly the same price, and keep it topped off with that maintainer when parked and sitting.

Batteries+ relabels a Northstar AGM battery as X2power, and adds another year to the 4 year warranty.

Lifeline batteries are top DOG deep cycle AGM, and still have more than enough cca to be used as a starting battery, and will stand a better chance or recovering from deeper discharges/abuse.



woody with a view - 12-6-2015 at 01:55 PM

it says it

desulphate 7v-11.5v
bulk 11.5 -14.4v
absorb 14.4v floats 13.6v

i left it plugged in 3 weeks ago for overnight. i'll let it sit this time for a week and watch it. it's already 12.2 but i realize that isn't rested volts. Thanks!

so is it worthwhile to hook up a 50 watt panel and your 10amp controller so i can "maintain" it using the sun?

PaulW - 12-6-2015 at 02:33 PM

Comments:
The purpose of a battery maintainer is to maintain not charge. Like was said above eventual charging will occur if the self decay rate of the batt is less than the maintainer provides, anyway it will take a long time if the batt is less than ~95% charged. Park your rig and the battery should be sitting above 13v. If so then a 0.75A to 2A maintainer will do its job to prevent battery self discharge.

Typical maintainer (of the 110v variety) will slowly charge the batt to 14.4v then turn off, then repeat when the voltage decays below 13.2v. Buy these things at Walmart for around $20. I have one for each of my vehicles that are used part year.

A simple solar panel will charge but not maintain. It will do a great job of ruining the battery due to overcharging. Combining a maintainer with a solar source is the way to go.

The latest consumer reports has their latest battery test results.
As usual the very high quality, high performance, and low production AGM batts were not tested. They test stuff for average use.

Battery charge status after resting for 12 hours:
Based of many test results from the batt literature
This table is just the general rule to determine how many amps should be used to try to bring the batt back.
12.6-12.8v 100% charged
12.4-12.6 75-100%
12.2-12.4 50-75%
12.0-12.2 25-50%
11.7-12.0 0-25%

Your car, truck, or boat should have battery voltage while running between ~14. and ~14.5. Then decay soon to just above 13v then after 12 hours rest the table above applies.

woody with a view - 12-6-2015 at 03:22 PM

the CHARGE side of this controller is for an inverter to connect to, i'm guessing. if so, i could hook up a 400watt inverter to the 100watt flex panel/10amp controller then plug in my maintainer to the inverter and have a worthwhile system, right?:?:

edit: foto

[Edited on 12-6-2015 by woody with a view]

41ceTp7Xy8L.jpg - 29kB

[Edited on 12-6-2015 by woody with a view]

landyacht318 - 12-6-2015 at 04:54 PM

No, hook the inverter directly to the battery over a short length of thick copper. Use AC extension cords to reach distant appliances.

Ignore the charge+- terminals in that diagram, that controller could never provide 400 watts through those load terminals. They probably have a 2 or 3 amp limit( 40 watts perhaps)

A good solar controller can maintain a battery at full charge, but there are some ideals possible in this regard that can greatly affect the outcome.

proper float voltage is temperature dependent.

Most AGM batteries want higher float voltages up to 13.6, where 13.6 on a hot fully charged wet battery will cause excessive water usage and destroy it if it is not watered in time.

the ability to set/adjust a float voltage is a huge factor in how well a solar controller maintains a battery.

a 5$ controller might not allow any adjustments at all, and its 'happy medium' one size fits all might not agree with the battery its usage, average temperature health or usage.

As a deeply cycled battery needs something different to reach full charge, than one lightly cycled.

Your optima's capacity has shrunk from chronic undercharging and sitting depleted.
Get it fully charged somehow, and then keep that maintainer on it during periods of rest, and it might give you a few more years of usage, or perhaps just a few weeks before that dreaded starter click.

my part man

captkw - 12-6-2015 at 05:34 PM

Who is boat owner (2) and has worked at the same place for 30 something years,, stopped selling optima's batts to RV and marine guys as he had Soo much trouble with them... when I inspect a vessel I will not procede till the batts are replaced with the correct batt/s and controller.. and as landyacht stated battery temp is very critical...One of the most misunderstood and often neglected things around is a battery IMO... deep clycle batts are used in smaller boats,, Sooo much that its a bad joke !! and should NEVER be used with a outboard !! Read the OWNER'S manual..Not what you cousin "Billy Bob" tells Ya !!

woody with a view - 12-7-2015 at 06:38 PM

i borrowed the neoghbors charger and set it on 10 amps for the past 24 hours. when i got home its floating so i unplugged it and set it to 2amp. i'll leave it there until the weekend and see what happens over the weekend. then i'll plug the maintainer in after i give back the charger.

thanks for the replies!

[Edited on 12-8-2015 by woody with a view]

brewer - 12-7-2015 at 07:56 PM

I'm looking for something similar. Just a solar powered battery charger I can take camping in remote areas and trickle charge my Dodge diesel batteries.

You know, if a kid leaves a light on and drains the batts. I also had my alternator go out last trip on the way home. I didn't shut it down until it was parked in my driveway. Batteries went pretty much dead.

I'm looking for some kind of solar charger that could charge me back up in the sticks if it happened again.

Thanks for any suggestions.

landyacht318 - 12-7-2015 at 08:34 PM

Expect about 5 amps of charging current when faced at the sun midday from this suitcase style portable 100 watt kit:

http://www.amazon.com/Renogy-Watts-Monocrystalline-Foldable-...

One could likely harvest about 45 Amp hours on an Equinox day if the panel is moved to face the sun morning, midday and afternoon.

A group27 battery ~12.5" long x 6.75"wide x 9.25" tall, 54 to 62 LB has 100 to 115 AH capacity at the standard 20 hour rate.

It is really difficult to have too much solar wattage, the only penalty is the size required to store it, and the initial price.

The linked kit above, well one pays extra for the portability factor, but could make one for less that is as, or more capable.

Thick copper is your friend when designing a system.

ncampion - 12-7-2015 at 10:01 PM

A good camping setup is a 100 watt panel with a small charge controller (sufficient capacity to handle the panel output) attached and wired to the back of the panel. A couple of alligator clips to attach to the battery and you will be fine. You just have to find a place to store the panel when not in use.

Whale-ista - 12-8-2015 at 11:00 AM

Would something like this help?

I use GoalZero products for multi-day off-grid camping trips to keep electronics charged. I have a Guardian, have not needed to use it (yet)

http://www.goalzero.com/guardian/

From website:

Keep 12V batteries charged and ready to go for when you need them most. The Guardian 12V Charge Controller plus Goal Zero Solar Panel is the perfect system to protect your batteries when they're not in use..

Maintain 12V Batteries
Trickle, recharge and maintain 12V batteries
Easy to Use
Small and easy to use
Plug it and Forget
Pair with a Goal Zero Solar Panel for a self-sustaining charging cycle

landyacht318 - 12-8-2015 at 11:15 AM

Do note that many charge controllers say not to disconnect from battery while panel is still in the sunlight making power, so a Simple easy peazy alligator clamp set up coming from a charge controller might release the magic smoke inside the charge controller.

Disconnect panel from controller first, or cover the panel if still light outside. Some charge controllers will not be bothered if removed from the battery while the solar is still providing current, but others WILL release their magic smoke.

There are all sorts of products with excellent marketing, their claims are misleading and sometimes just outright outlandish, especially when aimed at a niche market and those with thick wallets burning a hole in their pockets.

There is a huge difference in the wattage needed to maintain a battery at full, compared to recharging a battery to full from 50%. The latter should get significantly more wattage, and if more than needed, the solar controller prevents overcharge, but then one has the capacity to run more things.

About 60 watts can run a 12v compressor fridge indefinitely in a sunny environment, but obviously more wattage gives a higher buffer.

Hook - 12-8-2015 at 01:27 PM

Quote: Originally posted by brewer  
I'm looking for something similar. Just a solar powered battery charger I can take camping in remote areas and trickle charge my Dodge diesel batteries.

You know, if a kid leaves a light on and drains the batts. I also had my alternator go out last trip on the way home. I didn't shut it down until it was parked in my driveway. Batteries went pretty much dead.

I'm looking for some kind of solar charger that could charge me back up in the sticks if it happened again.

Thanks for any suggestions.


You're really asking for two things here. If all you really wanted was a trickle charge to prevent discharge while the truck sits for long periods, then a solar panel that puts out about 1.5a MAX doesnt even need a charge controller, IF the battery is ~ a standard 100ah battery.

But then you mentioned needing to charge the battery back up in the case of a significant discharge and to accomplish this with solar, you need AT LEAST a 100 watt panel (ideally more than that) and that means a charge controller as well. This setup WILL trickle but charge controllers are so smart now that they will first top off the battery if it determines it needs it. Most wont allow you to set it on straight trickle.

To get the most life out of any permutation of a lead/acid battery, they really prefer a bulk/absorption rate that is about 20% of their amp/hour capacity. Charging at lower rates runs the risk of slow death by sulfation. So, a 20amp rate somewhere north of 14.2v (depending on the type of battery) is ideal for a 100ah battery. That's a lot more than a single 100w panel can deliver.

But this is a description of the IDEAL setup. Many of us, including myself, just dont have the convenient space to be dealing with ~200+ watts of solar panel in a portable setup. So, I have a 130w panel that I have seen put out as much as 11amps at ~14.2-14.4 volts. My group 31 Lifeline battery is now 3-4 years old and seems fine. I actually disconnect it from the solar panel for a month or so and then let it go through the whole process of bulk/absorption/trickle when I re-connect it. I have read that that is better for an AGM than a constant trickle.

BTW, from what I have read, 13.6 is too HIGH a voltage to be trickling many AGMs. Check with your battery mfgr.

I dont know why we are on the subject of AGMs. For the scenarios described by Woody and others, it sounds like they want charging/maintaining for a starting battery and AGMs are ill suited for that.

But if there is ANY way to configure your vehicle so that it has a starting battery and a second "house" battery, consider doing it. If isolated properly and with a switch to combine the two when needed, your worries about discharging one or the other are greatly reduced. They make two-bank charge controllers that you can assign a percentage of the generated panel current to one or both of the batteries. And when one is finished charging, the other gets the rest of the available juice, automatically.

There are companies that make battery holders that attach to the chassis. It doesnt have to go in the hood, where there is usually no room in todays vehicles. But you will have to run some serious battery leads to it.

woody with a view - 12-8-2015 at 05:58 PM

24 hours at 2amps produced a 12.97v when i unhooked the charger and added the maintainer it is now 12.62 after an hour. the battery starts the truck strong as ever although i haven't started it in 3 weeks. is the consensus that since it isn't sitting north of 13v its compromised?

from the optima site, i'm confused:
However, if you store the vehicle for long periods with the alarm system engaged without maintaining the battery, you should use an OPTIMA YELLOWTOP® since the amperage drain over several weeks would damage a REDTOP® and reduce its life. (no alarm engaged on my truck)

Yes, and you can use any charger on an OPTIMA Battery as long as the voltage is regulated properly. If your charger will remain on indefinitely, the voltage should be at 13.8 volts maximum with a one-amp maximum current. (but i'm sitting at 12.6ish after two days of charging.)

:?::?::?:

wessongroup - 12-8-2015 at 07:01 PM

Sure glad I don't have to worry about it ... :biggrin::biggrin:

Have an Optima Red Top ... just sits in the Bronco

With both the positive and negative off

Has been fine for right at 5 years, but, I haven't ever put a VOM on it ... It just starts

Did have it taken out by my kid and put in on the bench ... and put a charger on it ... trickle charge for a few days ... till all green ... the kid had used it and left the ground connected and it went dead

Its back in the Bronco ... disconnected ... when I start it ... just put the connectors back on it ... and it fires right up

Have gotten a new "jump starter" with Lithium Ion battery ... my old Xantrax's battery's wore out ... and this was cheaper and lighter than the Xantrax battery .. .replaced a couple over 10 years

Has nothing to do with the question of the thread ... for a solar charger ... I do have one panel which I have set up for that ... but, it is not "mobile" and either am I ... :biggrin::biggrin:

Energy Power Jumper(TM)P6, 12000 mph, ... said it wouldn't work on a 5.0L engine .. started up the Bronco just fine

Good luck on the solar application



[Edited on 12-9-2015 by wessongroup]

msteve1014 - 12-8-2015 at 08:48 PM

Quote: Originally posted by woody with a view  
24 hours at 2amps produced a 12.97v when i unhooked the charger and added the maintainer it is now 12.62 after an hour. the battery starts the truck strong as ever although i haven't started it in 3 weeks. is the consensus that since it isn't sitting north of 13v its compromised?

from the optima site, i'm confused:
However, if you store the vehicle for long periods with the alarm system engaged without maintaining the battery, you should use an OPTIMA YELLOWTOP® since the amperage drain over several weeks would damage a REDTOP® and reduce its life. (no alarm engaged on my truck)

Yes, and you can use any charger on an OPTIMA Battery as long as the voltage is regulated properly. If your charger will remain on indefinitely, the voltage should be at 13.8 volts maximum with a one-amp maximum current. (but i'm sitting at 12.6ish after two days of charging.)

:?::?::?:


Buy a new battery before you really need it, like now.

Those numbers are not good.

landyacht318 - 12-9-2015 at 12:59 AM

I could likely get the battery to rest at a higher voltage with my adjustable voltage power supply, but the effects might only be temporary.

I would not necessarily assume your trickle charger actually fully charged the battery.

I am not sure I would count on that battery if in a locations where its sudden failure were going to cause a serious issue.


Put a digital voltmeter directly on the battery terminals when cranking the engine. If it cranks for less than 2 seconds and the voltage stays above 10.2 or so, I'd keep it and just carry jumper cables.

Its capacity is compromised, to some unknown degree. But if kept on a maintainer, and never discharged except what is used to start the engine, it could last a lot longer.

Any battery in a 3 week slow discharge situation is not going to be a happy battery. but a larger battery will have less of its capacity slowly used over those 3 weeks.
And optima batteries have ~25% less capacity than a rectangular AGM.

Hook - 12-9-2015 at 07:35 AM

Agree with the other posters. If that battery wasnt pulled north of even 13.2 while on the trickle charger, then something is likely wrong with the battery. Failure by the charger is possible; what voltage is it putting out without any load?

And the decay rate of the voltage, after charging, is not good. That leads me to believe it is the battery.

As landyacht mentioned, the capacity of all the Optimas is significantly less than a conventional rectangular battery. So if you are counting on using the battery to start a car AND run appliances of some kind, you'd be better off with a rectangular AGM hybrid battery. Something to think about if you need a new one. Of course, sizing in a Toyota engine compartment can limit what you can buy. A group 31 size is probably too tall.

msteve1014 - 12-9-2015 at 09:24 AM

Quote: Originally posted by woody with a view  
the battery starts the truck strong as ever although i haven't started it in 3 weeks.


FWIW. I thought my truck cranked over the same as always, but when I had some other work done the mechanic noted that it cranked somewhat slow, and since my batteries were 6 years old maybe I should think about changing them.

Disconnected the batteries. One rested at 12.9, the other at 12.4.
New batteries. The starter sounds like it has been turbocharged. :light:
Seriously, You would not believe the change.
That guy sees lots of Ford diesels. I only drive one, and it changed so slowly I never noticed a difference.

woody with a view - 12-9-2015 at 06:25 PM

i don't use it for anything but starting the truck. all my other stuff in Baja is run off a stand alone solar system. i may just swap this into my daily driver and spring for one of the batteries mentioned here if i can get a decent refund under warranty.

assuming my truck sits for weeks at a time in the future i should always put the maintainer on the new battery, eh? my truck sits unlocked and un-alarmed.

brewer - 12-9-2015 at 07:27 PM

Sounds like you have some kind of a draw or a short somewhere. My Mex truck sits for up to 3 weeks at home and nothing changes. Consistent volts. Batteries are a little over a year old.

Alm - 12-9-2015 at 08:09 PM

Quote: Originally posted by motoged  
Nomads,
What recommendations do you have for a portable solar (trickle) charger for deep cycle car/boat battery that won't overload battery that costs under $100?

You need to be more specific.

"Car" battery??? Like starter? Like, keeping it topped up when not in use?

There are panels on Amazon starting from $20 and up to $60. Getting more expensive won't make sense, since they all are just panels with night diode, no controller to limit overload. OTH, 2.5W panel won't overload an average starter battery.

The second part of the question is where it gets confusing.

Car batteries are not deep cycle. Boat batteries are (usually) hybrids, can be called "deep cycle", alright. So... What exactly do you need, and what for?

Assuming all the missing info (not read all the 30 posts that might have contained those missing bits) - what you need is a fulltime "solar system" complete with "controller". Check solarblvd.com -> controllers. Also, check their panels.

It is NOT possible to suggest anything further because there is not enough data. Depth of daily discharge (your energy usage, in other words) is the biggest unknown.

Start with energy audit - estimate how many watt-hours or amp-hours you use daily. Multiply this by 1.5, to err on caution side. Then report back and I'm sure somebody will tell you required size of panel and controller. There is nothing to it.