Trojan 27TMH Batteries

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richardbrennan

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Having not got any replies tacking this question onto another thread; I am posting it as a new one. I am thinking of replacing my Domestic Batteries which are Lifeline AGMs but the cost is rather putting me off doing a like for like replacement. Obviously the Trojan T105s seem to be the "Bees Knees" but I would have difficulty fitting these in my current battery boxes. I am thinking of the Trojan 27TMH 12 volt batteries; does anyone have experience of these?
 
I considered a wide range of batteries in 2012 and T105s came out as the best value for my needs. Unfortunately, that meant rebuilding my battery box as T105s were just slightly too big to fit. As it happened, they were a few mm smaller than the size quoted and would just have fitted. Worth rebuilding the box though as I could fit forced ventilation more easily.

I also considered Trojan 12V as an alternative and actually asked Trojan for how well they performed vs. T105s. They sent back a graph showing that their 12V range only had 50%the expected life of the 6V range. I think the graph showed T105s vs. 27TMH (and also 24TMX, 27TMX & 30XHS). I checked again and asked specifically "you mean that the T105s should last twice as long in same type of use vs. the 12V battery?" and they answered "yes".

So it was a no brainer as the 12V Trojan batteries were actually more expensive as well a only half the expected life of T105s.
 
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Thank you Mistroma for your very helpful reply. I will go down and measure my boxes again and see if the T105s would fit. The additional width is just 10 mm which should not be a problem, but the additional height of 28 mm may be more difficult. I find it hard to understand why there should be such a difference between the 6V and 12V types.
 
I saw your question on my thread.
I have just measured for T105's and was going to buy them. Plenty of room for the footprint, unfortunately they are too high, and the lid of my large battery box is the seat at the chart table.
I was considering 2 x 12 volt 27TMH, but I decided that the extra cost as well as changing all the terminals was getting too much.
Having now read what Mistroma had to say I am glad I decided on two Numax, not my first choice but I'm sure they will do for what I need.
 
Fitting a 12V Trojan would have avoided any problems with the battery box. It would have been reasonable to pay slightly more to avoid having to alter my battery box, so I was disappointed to find the difference I mentioned.

TrojanCycles.png


The graphs are based on an optimised charge/discharge cycle and batteries are returned to 100% during every cycle. You won't achieve these numbers in real life but about 50% seems to be a common assumption. However, the graphs are a useful way to compare different battery models.

Trojan "Smart Carbon Technology" gives 15% more cycles for T105 RE than normal T105s when heavily cycled at partial state of charge. So T105 RE should last quite a bit longer than older T105s in normal yacht usage cycling mainly in 50%-80% charge range.
 
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richardbrennan said:
You ave lost me a bit; what's the difference between a T105 and a T105 RE?
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Sorry, had to cut post short before I'd finished. I meant to add that Trojan seem to have come up with a "new improved" version of T105 and call it T105 RE. They refer to it as "Smart Carbon Technology" and you can read about it on their website.

I'd guess Numax ought to give about half the life you'd get from Trojan 27TMH but at a much lower cost. So not a bad choice if you can't fit T105s.
 
richardbrennan said:
Thank you Mistroma for your very helpful reply. I will go down and measure my boxes again and see if the T105s would fit. The additional width is just 10 mm which should not be a problem, but the additional height of 28 mm may be more difficult. I find it hard to understand why there should be such a difference between the 6V and 12V types.
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A word of caution... I replaced my engine start battery this year with a battery that has the same overall dimensions, as both quoted in the tech specs and measured by me (Old engine start was Odyssey, and I was replacing it with an AGM the same as my domestics). The battery box is quite tight, but the old one came out easy, but I had to enlarge the box to get the new one in... I think maybe the main difference was the handles on the old were one and each end and the new was a single centre handle
 
For anyone thinking of buying T105s and are worried about footprint, suggest they physically measure them first. In common with Mistoma, I found them to be slightly smaller than quoted and they just fitted the width in my boxes which were designed for leisure.
 
GrahamM376 said:
For anyone thinking of buying T105s and are worried about footprint, suggest they physically measure them first. In common with Mistoma, I found them to be slightly smaller than quoted and they just fitted the width in my boxes which were designed for leisure.
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In general the T105's footprint should not be any bigger than most leisure batteries which seem to run at about 175 x 300, but at 281ml high it is by far one of the tallest. Good job I double checked before ordering.
 
I've always used Numax - normal vented wet cell type. Still available at £60 inc vat and delivery - for the 75 amp ( the old ones were 85amp - open fillers )
Mine are still hanging in there @ 9 years old - but dropping now under any heavy load.
Engine is at least 6 years old and will still show its green light.
Am about to buy two more while I can still get them !
 
KREW2 said:
In general the T105's footprint should not be any bigger than most leisure batteries which seem to run at about 175 x 300, but at 281ml high it is by far one of the tallest. Good job I double checked before ordering.
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My T105s weren't as high as shown in the spec. either. Length and width should have made them a couple of mm too big to fit but they would have had 1mm to spare per battery. I could just have managed with height as well but there was an aluminium support across the top of the box at one end. I wasn't happy to just fit insulation. Checking and filling would also have been a problem because I'd have to remove 2 batteries in order to slide the others forward by 40mm to access the last caps.

I moved a bulkhead by 25mm, lowered the floor quite a bit, glassed bottom sections and fitted ducting at the top for forced ventilation. A bit of a pain but better than squeezing in the T105s. I just assumed that Trojan gave height with largest posts and I had the ultra-low version.
 
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