Solar Charger

[AJack]

Will this (Battery Tender 15W Solar Charger 021-1165) work to charge & maintain the batteries in a 2018 SX240 with dual batteries?
https://www.amazon.com/dp/B004Q820TQ/ref=twister_B00UYBAP0K?_encoding=UTF8&psc=1

I've read many threads, but really don't see any real solutions, besides creating a system. Will this all-in-one system work? My boat is stored in a fenced-in grass area without access to power.

My batteries are hovering around 12.1 volts, and I read that below 12 volts leads to starting issues.

Advanced thanks.

 

[Jgorm]

Yeah, it will work. If you have ac power there are better and cheaper options. The cheap harbor freight panels work decent for 20 bucks. I had a norco solar and it totally sucks.

 

[Mainah]

It will work to maintain 1 battery. Keeping the batteries isolated and charging vs maintaing is a whole other matter. To actaully charge and maintain two large batteries in isolation you will need a dual battery charge controller and 100 rated watts of solar panel input into the controller. Truly charging a single large deep cycle battery requires at least 2 amps and maintaining requires at least .5 amps when cycled on. Solar panels only ouput rated watts in direct sun in the summer (northern hemisphere) and angled correctly for your location.

I recommend doing more research to meet your needs.

 

[AJack]

It will work to maintain 1 battery. Keeping the batteries isolated and charging vs maintaing is a whole other matter. To actaully charge and maintain two large batteries in isolation you will need a dual battery charge controller and 100 rated watts of solar panel input into the controller. Truly charging a single large deep cycle battery requires at least 2 amps and maintaining requires at least .5 amps when cycled on. Solar panels only ouput rated watts in direct sun in the summer (northern hemisphere) and angled correctly for your location.

I recommend doing more research to meet your needs.

Appreciate your response, and it seems that you have knowledge in this subject. This is exactly why I posted to the boards to find information because responses like this leave me without an answer. It seems to suggest that the item I hyperlinked will not suffice, so is there something similar that does? I live in Tampa, Florida, which I would assume provides a fair amount of sunlight. I do not, and will not have access to AC at the storage location, as stated, it's in a fenced-in grass yard (I live on a military base) out in the boonies of the base. It is against the regulations to keep a boat/trailer at the on-base house. Any help will be appreciated.

 

[AJack]

Yeah, it will work. If you have ac power there are better and cheaper options. The cheap harbor freight panels work decent for 20 bucks. I had a norco solar and it totally sucks.

This is why this gets confusing, you say yes, the next post says no. I am still in a situation with a boat without AC access and the batteries are getting drained, even though I've used it every weekend. I may end up having to pull the batteries prior to placing it in storage - what a PITA!

 

[Jaylex]

One thing I have seen a buddy of mine do, which is in extreme circumstances is hooked up his little generator and charge his two batteries and just let it run out of gas. Not the optimal solution I know, but sounds like this might be an extreme case, and unless you want to pull the batteries not sure what the best options are.

Sounds like the solar panels might not be robust enough to charge it, but might be the easiest option, and then you can just keep an eye on them to see if it drops significantly.

Keep in mind your start battery might be solid, and the drain would likely be mostly from the house if your running your system and have the house on all weekend...not sure how true that is, but just my hunch. So you might just need to pull one battery vs two..., anyone got some insight?

 

[Mainah]

Appreciate your response, and it seems that you have knowledge in this subject. This is exactly why I posted to the boards to find information because responses like this leave me without an answer. It seems to suggest that the item I hyperlinked will not suffice, so is there something similar that does? I live in Tampa, Florida, which I would assume provides a fair amount of sunlight. I do not, and will not have access to AC at the storage location, as stated, it's in a fenced-in grass yard (I live on a military base) out in the boonies of the base. It is against the regulations to keep a boat/trailer at the on-base house. Any help will be appreciated.

Always happy to help out a fellow brother (I am a Vet). If your are good with blind faith below is what you need. That plus a 100 watt aluminum framed solar panel and some wiring. Lots to choose from on the last two on Amazon but the controller below is a big key. You will also have to do the dvsr engine on only mod which you can find on this site. Total cost for everything should be around $200 including wiring and connectors.

EPever Dual Battery Solar Charge Controller 20A 12V 24V Duo-Battery Solar Controller... https://www.amazon.com/dp/B01N1ZL9EK/ref=cm_sw_r_sms_c_api_4vADBbSF4XZW9

 

[Mainah]

Almost forgot point the panel true south and and at a 25 degree angle from flat level (for location of OP) to achieve maximum output.

 

[Jgorm]

This is why this gets confusing, you say yes, the next post says no. I am still in a situation with a boat without AC access and the batteries are getting drained, even though I've used it every weekend. I may end up having to pull the batteries prior to placing it in storage - what a PITA!

100w is over 7a at 14v. Set the switch to all, or manually connect the positive terminals and it will work just fine. I've been charging multiple batteries off the same charger for years. That's exactly what the boat does when charging. It's like hooking two buckets of water together. The more full bucket will charge the less full, but then the charger will fill both of them. Yeah, it may be slightly better to have two independent chargers, but one will work fine. I charge my Yamaha Viking and waverunner on the same 3.5a 3 stage charger. The most important thing is the 13.0 float charge once the amps come down. There cheap ones will boil off the water off wet cell batteries much faster.

 

[the MfM]

I have the 10w solar battery tender.

I leave my boat on my mooring and hook up the panel to the battery. I use a rope from the port to starboard cleats to hang the panel on the outside of the mooring cover.

It’s not at the correct angle and is almost never facing south.

Yet the little indicator light goes from yellow when I plug it in Sunday afternoon to green by the time I get back to it Friday evening. Indicating the battery is fully charged.

So @AJack I say go for the solar tender, it works.

 

[AJack]

I have the 10w solar battery tender.

I leave my boat on my mooring and hook up the panel to the battery. I use a rope from the port to starboard cleats to hang the panel on the outside of the mooring cover.

It’s not at the correct angle and is almost never facing south.

Yet the little indicator light goes from yellow when I plug it in Sunday afternoon to green by the time I get back to it Friday evening. Indicating the battery is fully charged.

So @AJack I say go for the solar, it works.

First hand experience!!! I'm assuming the 15W would be quicker.

 

[the MfM]

First hand experience!!! I'm assuming the 15W would be quicker.

If you use something like the blue sea ACR to combine batteries while charging I’d get the 15w.

Or you could get a 10w for each battery. Redundant and simple. Not much difference in price in the end.

 

[Mainah]

Think of a battery like a bucket of water where the water contains electrons (electrolyte) that like to float to the top. If left to sit out the electrons will evaporate slowly off the top. A small watt charger will only keep the electrons from evaporating by supplying new ones to the top keeping the old ones forced down. The voltage that is read from a battery during and after charging is just the voltage from the top (surface charge). To truly charge a battery you have to push more electrons down with takes far more watts. Yes this is an over simplification that does not discuss the anode, cathode, cells, etc. but most of us are not electro-chemical engineers. Keep in mind I am just a guy on the internet that thinks he has a good grasp of the principles at play and is attempting to explain something complex with an oversimplified analogy.

Small all in one solar battery tenders do a great job of supplying enough electrons to the top to keep the old ones from escaping and sometime supply enough to add very slowly but not truly and fully deep. The built in circuits which prevent discharge and overcharge are very simple and in general keep the electrolyte from boiling. The small all ones are not true smart controllers which have selectable battery types and cut off the juice to the battery to get a true voltage measurement. Some all in ones with led indicators use more juice in the led than they output to the battery. The size of the battery matters as well where a larger battery will need more watts to maintain or charge than a smaller one. With no mods and plenty of mid to high range rpm run time without sucking down lots of battery juice prior to putting away two small all in one solar tenders will do the job as combining banks of batteries of different types sizes, age, and conditions should be avoided. If you have amps for a stereo and draw the batteries down more than the stators can charge back up prior to shutting off the engines and storing the boat then the batteries will need to be charged to keep their life span. In my case I have two large batteries with huge demand on them from everything that I have added to my boat (amps, ballast pumps, inverter for kegerator and blender, hi amp inflator) . My batteries require charging every time after I pull it into its slip which I accomplish with a dual bank plug in charger.

A two year old 100 amp hr deep cycle battery will lose roughly .5 amp hours per day if not hooked up to a charger. A solar panel rated at 15 watts in near ideal conditions will really only convey .25 amp hours to 2 amp hours per day depending on many factors. With two batteries the need of course doubles. To truly deeply charge a battery that was not fully charged when put away multiply by 2 to 3x depending on type, age, size, condition etc. That is how I came to my recommendation for the OP.

Putting a small watt all in one solar tenders on two banks that are combined but sit for long periods of time is far better than doing nothing. Putting two small watt all in one solar tenders (one per bank) and keeping the batteries isolated is far better than the latter. Putting a true two bank smart solar controller on a two bank system and providing enough watts to deeply charge the batteries is even better. My recommendation of 100 watts assumes deeply charging the both batteries at the same time. They can be set to charge one then the other in which case a 50 watt panel would suffice but may be a bit less than ideal in winter which is still boating season in Florida for some. I am the type that always airs on the side of caution with anything electrical so I say for a 25% price difference and a 100 watt panel only costing about 100 bucks why not go for the one that will output twice as much and never have to worry.

In order to accomplish isolation with the stock DVSR on late model yamaha's one must cut the small red loop and put a switch in line or connect the switched end to an engine on wire. There is already a thread on that here. Yes the DVSR combines the batteries when it turns on but with this engine on mod ~ 20 amps of juice is flowing from the stators which significantly offsets the harm of combining them.

Last part I promise. Electrical current is dangerous. Make sure to cover solar panels with something to block the sun from getting to it when making connections.

Happy battery charging.

 

[the MfM]

I don’t know about that fancy mathing.

But I can tell you when I bought the boat the engines wouldn’t turn over without a jump pack. Hooked up the 10w solar tender. Figured I was going to need a new battery. It took 6 weeks but the led indicator turned green. Never had to use a jump pack again or real charger. :dunno:

 

[Mainah]

I don’t know about that fancy mathing.

But I can tell you when I bought the boat the engines wouldn’t turn over without a jump pack. Hooked up the 10w solar tender. Figured I was going to need a new battery. It took 6 weeks but the led indicator turned green. Never had to use a jump pack again or real charger. :dunno:

That is awesome. Please post what brand/model 10 watt you got. Sounds like a budget winner.

 

[the MfM]

That is awesome. Please post what brand/model 10 watt you got. Sounds like a budget winner.

The 10w version of what a jack posted

Deltran solar battery tender

https://www.amazon.com/dp/B004Q86JJ8/ref=twister_B00UYBAP0K?_encoding=UTF8&psc=1

The battery is a type 24 deep cycle marine from Walmart.

 

[AJack]

I've been browsing even more of the threads on this forum, and I think I'm understanding the charging situation. The 15W will charge the batteries, but not necessarily to a "deep" state due to the low wattage while the 100W panels can provide the needed requirements to charge the two batteries.


In comparison:

15W Solar charger/maintainer by Battery Tender ($104.65)
This all-in-one is a 15W solar panel providing about 1.25 amperes, requiring about 160 hours of optimal sunlight to effectively charge the two batteries.

The combination of ($180.95) is a 100W solar panel, providing 8.3 amperes during optimal sunlight, requiring about 24 hours of sunlight needed to charge the two batteries.
*EPever Dual Battery Solar Charge Controller 20A 12V 24V Duo-Battery ($42.99)
*Newpowa 100 Watts 12 Volts Polycrystalline Solar Panel ($98.70)
*BougeRV 20 Feet 10AWG Solar Extension Cable MC4 ($29.98)
*Ancor Marine Grade Primary Wire 16AWG 18 Feet ($9.28)
*DVSR Engine On Mod (Relatively free, needs marine grade wire)

If so, I'll begin ordering the 100W "kit" and try to document this, so someone else doesn't have to in the future.

 

[Zizzou 192]

I use the battery tender 15w solar panel charge controller combo connected through the 12v cig lighter plug in my wet slipped boat. It maintains both boat batteries with no issue while placed on the boat windsheild roped to the center cleats.

 

[Compatico]

I use an 80w panel with an electronic charge controller to keep my 12v marine battery topped up during the winter months. I really only need a 15-20w (over 1A current) to keep it topped up, but it was on sale for just $10 more and I keep it on the boat in the summer to help keep the battery topped up when anchored and listening to tunes. My next boat will have dual batteries, but 80w is more than enough to keep them both topped up all winter (80w is over 5A of current on a bright sunny day). I'll just connect them in parallel with battery cables.

 

[TiMaH]

Think of a battery like a bucket of water where the water contains electrons (electrolyte) that like to float to the top. If left to sit out the electrons will evaporate slowly off the top. A small watt charger will only keep the electrons from evaporating by supplying new ones to the top keeping the old ones forced down. The voltage that is read from a battery during and after charging is just the voltage from the top (surface charge). To truly charge a battery you have to push more electrons down with takes far more watts. Yes this is an over simplification that does not discuss the anode, cathode, cells, etc. but most of us are not electro-chemical engineers. Keep in mind I am just a guy on the internet that thinks he has a good grasp of the principles at play and is attempting to explain something complex with an oversimplified analogy.

Small all in one solar battery tenders do a great job of supplying enough electrons to the top to keep the old ones from escaping and sometime supply enough to add very slowly but not truly and fully deep. The built in circuits which prevent discharge and overcharge are very simple and in general keep the electrolyte from boiling. The small all ones are not true smart controllers which have selectable battery types and cut off the juice to the battery to get a true voltage measurement. Some all in ones with led indicators use more juice in the led than they output to the battery. The size of the battery matters as well where a larger battery will need more watts to maintain or charge than a smaller one. With no mods and plenty of mid to high range rpm run time without sucking down lots of battery juice prior to putting away two small all in one solar tenders will do the job as combining banks of batteries of different types sizes, age, and conditions should be avoided. If you have amps for a stereo and draw the batteries down more than the stators can charge back up prior to shutting off the engines and storing the boat then the batteries will need to be charged to keep their life span. In my case I have two large batteries with huge demand on them from everything that I have added to my boat (amps, ballast pumps, inverter for kegerator and blender, hi amp inflator) . My batteries require charging every time after I pull it into its slip which I accomplish with a dual bank plug in charger.

A two year old 100 amp hr deep cycle battery will lose roughly .5 amp hours per day if not hooked up to a charger. A solar panel rated at 15 watts in near ideal conditions will really only convey .25 amp hours to 2 amp hours per day depending on many factors. With two batteries the need of course doubles. To truly deeply charge a battery that was not fully charged when put away multiply by 2 to 3x depending on type, age, size, condition etc. That is how I came to my recommendation for the OP.

Putting a small watt all in one solar tenders on two banks that are combined but sit for long periods of time is far better than doing nothing. Putting two small watt all in one solar tenders (one per bank) and keeping the batteries isolated is far better than the latter. Putting a true two bank smart solar controller on a two bank system and providing enough watts to deeply charge the batteries is even better. My recommendation of 100 watts assumes deeply charging the both batteries at the same time. They can be set to charge one then the other in which case a 50 watt panel would suffice but may be a bit less than ideal in winter which is still boating season in Florida for some. I am the type that always airs on the side of caution with anything electrical so I say for a 25% price difference and a 100 watt panel only costing about 100 bucks why not go for the one that will output twice as much and never have to worry.

In order to accomplish isolation with the stock DVSR on late model yamaha's one must cut the small red loop and put a switch in line or connect the switched end to an engine on wire. There is already a thread on that here. Yes the DVSR combines the batteries when it turns on but with this engine on mod ~ 20 amps of juice is flowing from the stators which significantly offsets the harm of combining them.

Last part I promise. Electrical current is dangerous. Make sure to cover solar panels with something to block the sun from getting to it when making connections.

Happy battery charging.

Based on research I (think) have decided to purchase 100 Watt ETFE flex panel with a DUAL solar controller as my 2016 SX190 has X2 12V 75A batteries. I do not have access to shore power at my wet slip and cannot install any permanent panel to the dock. I plan on simply attaching the flex panel to my mooring cover as weight is the biggest issue.
CAN SOME PLZ help me out with this DVSR MOD I keep reading about.... I do have both batteries on a DVSR at present -

Thank you ....