compact starter batteries

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oldvarnish

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I've always thought biggest was best when it came to batteries; but these new compact ones look attractive - and I could make use of the space I save.

Any experiences to share.

I'm hanging it off a 38HP Volvo.
 
Excellent product. I have one (Red Flash) and it does what is claimed. If you only use it for starting then a capacity of around 40 ah is enough. Best used with a VSR to split charge. I have a BEP Marine switch cluster which includes a VSR. Only downside is cost, but potentially very long lived. I also have one in my Morgan which is now 10 years old.
 
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Red Flash High Rate are excellent batteries for the job with huge start current capability.
What you lose is the reserve capacity, i.e. the low rate ampere hours, so it's important to keep it just to engine starting, and keep it well charged.
For technical info on them go to http://www.dmstech.co.uk/product_details.php?type=15&brand=6&flag=3&pro_id=15
DMS are the master distributor and technical authority for UK, some of their sub-distributors put out over optimistic figures.
You can also buy direct from them http://www.dmsshop.co.uk/red-flash-high-rate-batteries-9-c.asp that way you will get the freshest stock and I don't think anyone undercuts them.
An alternative is Odyssey, also available through DMS http://www.dmsshop.co.uk/odyssey-batteries-44-c.asp

Disclosure - years ago I was responsible for supplying these batteries to DMS when I worked for the manufacturer. No connection now.
 
It certainly sounds like a good idea. I reckon we have a fairly typical cruising layout with 3 house batteries and a truck battery for starting. I am sure we could squeeze in one of those Red Start batteries somewhere which would leave space for 4 deep discharge ones.

I will have to keep away from this forum. Every day the wish list gets longer and longer.
 
I have used a Red Flash 1000 as the starter for my 28HP Volvo2003. It has done 7 seasons so far with no problems. I keep it topped up in the winter with a 10w solar panel.
I use on of those antiquated 1/2/both switches without any problems as well.
 
I also use a red flash to start a volvo D1-30. It's separated from the domestics and charged by a Stirling alternator to battery charger. It's worked well for 3 years and has allowed me to use the two battery boxes for 2 domestic batteries.
 
I fitted an optima redtop 4.2 to start my 50HP Perkins 4108. CCA of 850 and 50AH. Works well, and actually has plenty in reserve - I have struggled bleeding the engine and have taken numerous attempts to start the engine and the battery has shown no signs being unable to spin the engine. Highly recommended.

Neil
 
oldvarnish said:
I've always thought biggest was best when it came to batteries; but these new compact ones look attractive - and I could make use of the space I save....
Click to expand...
I've have a 27Ah RedFlash for 10 years lying on its side in the bilges. Only used for starting a 56Hp Yanmar. Charged by a 5 watt Solar panel in the Med - occasionally paralleled with the service batteries when motoring via a switchable on/off/manual BEP VSR.
 
I have a Red Top 25 for starting my 1GM10 - works fine. One advantage of the AGM batteries is that they can be located anywhere, in any orientation - the ventilation requirements associated with vented batteries don't apply - coupled with their compactness it opens up more possibilities for locating them. Mine is wired through an off - 1- both - 2 switch, I run with just the starter battery connected for 10 minutes or so, then switch to charge the domestic battery. I don't run with both connected other than when switching over. I have a charge controller [Adverc].
 
The batteries themselves are great - but when I looked into this it was suggested that the voltage needed to charge a wet-acid house bank at its maximum rate would be too high for the sealed starter battery. Current is shared according to need, but the voltage is the same throughout the system unless you're using a clever charger box like DuncanHall above.

I think it was DMS who told me this - certainly it was a battery supplier, on the phone - but maybe there was a misunderstanding somewhere? I'm not fully convinced.

Pete
 
prv said:
The batteries themselves are great - but when I looked into this it was suggested that the voltage needed to charge a wet-acid house bank at its maximum rate would be too high for the sealed starter battery. Current is shared according to need, but the voltage is the same throughout the system unless you're using a clever charger box like DuncanHall above.

I think it was DMS who told me this - certainly it was a battery supplier, on the phone - but maybe there was a misunderstanding somewhere? I'm not fully convinced.

Pete
Click to expand...

I contacted both DMS and Adverc when I was planning this. If my recollection is correct, the voltages that the Adverc delivers are not as high as some of the other higher rate controllers, so it was not a problem with my set-up. But it was a good idea not to leave the starter battery in parallel with the domestic bank for long periods while charging.
 
rgarside said:
But it was a good idea not to leave the starter battery in parallel with the domestic bank for long periods while charging.
Click to expand...

Right, I think that's what they told me too. It's jogged my memory :). The problem wasn't that the bulk charging rates were so different, but that once it was fully charged (very quickly), the starter battery would prefer to be held at float voltage. However, as long as the house bank still needed topping up, the voltage in the system would remain at bulk levels, to the detriment of the starter battery.

Maybe it's one of those things where the manufacturer is concerned about ideal treatment, but in practice the effects of less-than-ideal are not too bad?

Pete
 
prv said:
Right, I think that's what they told me too. It's jogged my memory :). The problem wasn't that the bulk charging rates were so different, but that once it was fully charged (very quickly), the starter battery would prefer to be held at float voltage. However, as long as the house bank still needed topping up, the voltage in the system would remain at bulk levels, to the detriment of the starter battery.

Maybe it's one of those things where the manufacturer is concerned about ideal treatment, but in practice the effects of less-than-ideal are not too bad?

Pete
Click to expand...
But if you had a traditional One Both Two switch could you not just wire the small starter battery to One, charge for 10 minutes and then switch to Two and isolate it from the charger ?
 
Storyline said:
But if you had a traditional One Both Two switch could you not just wire the small starter battery to One, charge for 10 minutes and then switch to Two and isolate it from the charger ?
Click to expand...

You can, but if you are going to the trouble of buying an expensive battery then worth installing a VSR and independent switching so you don't have remember to change over. The setup I describe in post#2 also has a paralleling switch for emergency starting using the house bank.
 
rgarside said:
But it was a good idea not to leave the starter battery in parallel with the domestic bank for long periods while charging.
Click to expand...

I also have a VSR set up, whereby the engine starter battery is charged first, then VSR closes to allow house batteries to be charged. But with this arrangement, the starter battery will see the higher charging voltage to the house batteries, rather than a float voltage for potentially a longer period until house batteries are charged. So, are sealed starter batteries vulnerable to damage in this situation?
 
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