usual battery conundrum

Scillypete

Scillypete

Well-Known Member
Joined
11 Jun 2003
Messages
1,927
Location
Isles of Scilly
www.peteandspamgosailing.blogspot.com
I currently have a domestic bank of 3 x 100AH batteries all are wet lead acid type. These were bought five years ago and since then they have had a fairly hard life (no mains plug in here) and needless to say that their performance has noticeably dwindled this season. I currently have two large solar panels (both 120w) for charging which usually does the job, previously it was a combo of wind and solar but the wind genny met with an untimely end a couple of years ago, so since then it has been solar only.
Now as the current (no pun intended) bank are clearly dying and need replacing I'm totally undecided on what I should be getting. The budget is obviously limited but I would like to get the best for the job. Question is, do I plump for similar wet lead acid possibly slightly higher AH with all the maintenance and potential leakage issues, or spend nearly double for a set of gel ones with no maintenance, or do I spend like I've won the lottery and buy a set of AGM batteries . . . . . are they really worth it?


I've been searching through and checking and re-checking prices and sizes and there are just so many I am now well and truly confused about which way to go.


It would be nice to have some extra wiggly amps than before but 300AH seemed to cope with most of the daily demands without having to run the engine to top up, for the first couple of years anyway. Then there's the weight issue are Gel and AGM's roughly comparable weight wise with lead acid?
 
Gel batteries generally are more expensive than AGMs. AGMs accept charge quickly, and are "sealed" so they're clean with no leaks, and no maintenance needed.

I use Exide Stop-Start AGMs, designed for the demands of modern cars. They're reasonably priced, the EK950 is 95Ah and is around £150.

If you want perhaps the longest life, consider a bank of 4 Trojan T105s - this will give you 450Ah but will cost around £600. They need regular maintenance, but should give good service for 8-10 years though.
 
Agree re gel batteries: safe, expensive, maintenance free but require accurate and controlled charging regimes. In a sophisticated installation, fair enough, but in normal yottie use it is possible to damage them beyond repair. Defo avoid.

Also agree with Trojan T105's if they fit, but being lead antimony they can have a 15% monthly self-discharge rate. However, if one can look after them they shld work out cheaper on a lifetime cost per amp basis compared to the so-called 'leisure batteries'
 
Scillypete said:
I currently have a domestic bank of 3 x 100AH batteries all are wet lead acid type. These were bought five years ago and since then they have had a fairly hard life (no mains plug in here) and needless to say that their performance has noticeably dwindled this season. I currently have two large solar panels (both 120w) for charging which usually does the job, previously it was a combo of wind and solar but the wind genny met with an untimely end a couple of years ago, so since then it has been solar only.
Now as the current (no pun intended) bank are clearly dying and need replacing I'm totally undecided on what I should be getting. The budget is obviously limited but I would like to get the best for the job. Question is, do I plump for similar wet lead acid possibly slightly higher AH with all the maintenance and potential leakage issues, or spend nearly double for a set of gel ones with no maintenance, or do I spend like I've won the lottery and buy a set of AGM batteries . . . . . are they really worth it?


I've been searching through and checking and re-checking prices and sizes and there are just so many I am now well and truly confused about which way to go.


It would be nice to have some extra wiggly amps than before but 300AH seemed to cope with most of the daily demands without having to run the engine to top up, for the first couple of years anyway. Then there's the weight issue are Gel and AGM's roughly comparable weight wise with lead acid?
Click to expand...

Since you do not have access to mains charging and have to rely on solar it will be very difficult to ensure your batteries are properly fully charged on a regular basis so you would be better of getting cheap and cheerful wet lead acid batteries similar to what you already have. If you get 5 years out of them that is pretty good for your charging regime.

Failing to charge any sort of Lead Acid battery (wet, gel or AGM) to 100% SOC on a fairly regular basis will result in shorter life and a gradual reduction in AH capacity over time.

I think you will be wasting your money going for Gel or AGM, firstly because you do not have the charging capacity to take advantage of the increased charge acceptance rates, secondly you are likely to find them knackered after 5 years because they will not be fully charged often enough.
 
I have T105s and no mains charging, and they have been as good as gold for 9 years now.

I guess the"best answer" for you is probably a Lithium battery, but they a chuffing expensive.

I would vote for 4 x T105s.
 
I would go for cheap and cheerful but partly because the boat is now in multiple ownership and some owners or their untrained crew are sure to damage expensive ones.
It is a more difficult decision for you as you are pretty battery dependant and presumably able to care for expensive batteries as they should be!
 
another vote for 4XT105 here, but in the Med and with 600W solar and no shore power, they barely sweat. Expect to last for 10yrs...

cheers

V.
 
You must log in or register to reply here.

Share this page

Top