Charging deep cycle batteries on the hook

[kamikater]

hello everybody,

we are currently cruising in central america and live on the hook.
we never go to marinas and fully rely on our solarpanels for electricity (no genset,no windgen)

we have a older solarboost 2512i that came with the boat (the one without equalizing function) the unit shuts at 14.2V

the xantrex link20 battery monitor shows 12.8/12.7V at night and 12.6v sometimes 12.5v in the mornings.

if the sun is shining we are usually full before noon (or whenever the solarboost decides to shut at 14.2v)

question: can i bypass the solar charge controller and hook the panels directly to the battery for equalizing if i watch the temp. and the voltage?

ps: we have a desulfator rigged aswell.

[thomm225]

Originally Posted by kamikater

hello everybody,

we are currently cruising in central america and live on the hook.
we never go to marinas and fully rely on our solarpanels for electricity (no genset,no windgen)

we have a older solarboost 2512i that came with the boat (the one without equalizing function) the unit shuts at 14.2V

the xantrex link20 battery monitor shows 12.8/12.7V at night and 12.6v sometimes 12.5v in the mornings.

if the sun is shining we are usually full before noon (or whenever the solarboost decides to shut at 14.2v)

question: can i bypass the solar charge controller and hook the panels directly to the battery for equalizing if i watch the temp. and the voltage?

ps: we have a desulfator rigged aswell.

You can always hook the panels directly to the batteries just watch the voltage.

I do it quite a bit with an extra panel I have that isn't going thru a controller. (but I do have an MPPT Victron Controller also)

Voltage on the panel may be 21- 22 volts or so without a load, but once connected to the batteries, it will drop to that voltage then you can monitor it as it rises

[john61ct]

Ideally one day replace the SC with one that lets you configure its charging profile to user-custom setpoints

Equalizing really should be done according to the mfg specific protocol for your batteries, and that requires some precision.

Victron' SmartSolar MPPT line is good value, depending on how many panels and total watts actually produced in your context.

[kamikater]

thanks for the replys.

we have two 125w panels.
any inputs on a affordable solar charger with maybe a equalizing function or user defined settings would be highly appreciated!

(so far we looking at epever and outback,but the outback is a bit too pricey)

[boatpoker]

Blue Sky SB3000i

[john61ct]

One Victron SmartSolar MPPT 75/15 would handle both just fine, maybe $120 delivered.

(For them that don't believe in overpaneling, a 100/20 would (in theory) be needed to capture every last amp in very rare peak conditions, likely only if tilted directly facing the bright sun on a very cold day.)

But **best** of all would be a 75/10 SC on each panel, given that the two panels are likely partially shaded in use, or especially if ever well-shaded at different moments.

[john61ct]

Originally Posted by boatpoker

Blue Sky SB3000i

Excellent tech!

For a pricey / fussy bank chemistry, add their IPN-Remote and get a full BM with explicit endAmps stop-charge control, similar to Bogart Trimetric and Midnight's WhizBang Jr

[john61ct]

Originally Posted by kamikater

looking at epever and outback,but the outback is a bit too pricey

Latter good stuff too, but Epever's not much of a step up, kind of units included with cheap mass-market kits.

MorningStar's another good marque.

[kamikater]

i don't know much about solar charge controllers,
can you tell me why a Victron SmartSolar MPPT 75/15 is better than a 75/30 or 75/20?

i don't mind a couple extra bucks,the price seems right and i like the blootooth option.

thanks you for your kind help!

[thomm225]

Originally Posted by kamikater

i don't know much about solar charge controllers,
can you tell me why a Victron SmartSolar MPPT 75/15 is better than a 75/30 or 75/20?

i don't mind a couple extra bucks,the price seems right and i like the blootooth option.

thanks you for your kind help!

The 75/20 (100/20) and the 75/30 (100/30) can handle more current than the 75/15 so if you plan to add more Panels etc then you might consider going with a controller rated for a higher current.

Go to downloads for explanations on each.

https://www.victronenergy.com/solar-...-20#datasheets

I have the 75/15 and am running just two 12 volt batteries in parallel with 155 watts worth of panels when all are connected with no fridge etc just lights, autopilot, inverters, depth, vhf, etc

[noelex 77]

I, too, live on the hook, relying virtually 100% on solar power and have done so for over a decade. For this to work you need an efficient solar charging system. The Victron 75/15 is a great controller, but it is too small for your 250w of solar. The advice that this would be a good choice is wrong. The Victron 100/20 or two Victron 75/10 units would be much better.

If you have the panels wired in series, double check the Voc for each panel is below about 42v for the Victron 100/20. Nearly all 125w panels will be below this voltage so it unlikely to be a problem, but it will damage the controller if this criterion is not met. There will be a sticker on the back of the panel listing the specifications.

A bulk/absorption voltage of 14.2v is too low so you do need to buy a new controller. and the adjustable voltage on the Victron will make equalisation much easier and safer than directly connecting the panels.

[daletournier]

I use two of these https://www.ecodirect.com/Blue-Sky-S...oost-2512i.htm

I divide 480w between them.

As the previous poster said 14.2v isnt enough to get your batteries full, they are walking down everyday. A charger such as the above is very adjustable and will serve your needs. I live fulltime on the hook and leave mine in absorb all day. They sit between 14.5v and 14.8v in the afternoon, I keep an eye on trailing amps.

[kamikater]

well,i got exactly that controler,the sb2512i...but i cant adjust much since i dont have the external remote wich costs another 210$.

for that price i'm rather buying a new unit,like victron or morningstar
and have my old solarboost as a backup.
(it's 10years old anyways,will probably break over the pacific

thanks anyways!

[daletournier]

Originally Posted by kamikater

well,i got exactly that controler,the sb2512i...but i cant adjust much since i dont have the external remote wich costs another 210$.

for that price i'm rather buying a new unit,like victron or morningstar
and have my old solarboost as a backup.
(it's 10years old anyways,will probably break over the pacific

thanks anyways!

Yep, forgot that. I added one after I bought my regs as I found the default inadequate.

Not sure how I forgot that as I look at it everyday. .lol.

[john61ct]

Originally Posted by noelex 77

The Victron 75/15 is a great controller, but it is too small for your 250w of solar. The advice that this would be a good choice is wrong.

Only mentioned for keeping things inexpensive.

Going for the more expensive options - which I stated were better - would yield in real life conditions only marginally better.

The single SC at 100/20 maybe 2-5% and then **only** in peak conditions, with a tilting mechanism.

The doubling up 75/15s maybe 10-20% improvement, in all conditions, but of course doubles the incremental cost.

Which of course is not an important factor for the wealthy, but I inferred the OP was not.