news Rolls Surette

[Megunticook]

I'm a little concerned about this new Rolls-Surette 24 M 85 battery I got for my sailboat (https://www.rollsbattery.com/wp-cont...ries/24M85.pdf). I'd been using an Exide Nautilus deep cycle that the previous owner bought, I hooked it up to a 40W portable solar panel with a MorningStar Sunsaver 6L charge controller. Worked great, don't think the battery status light was ever anything but green. Since that battery had seen 5 seasons, I figured why not play it save and invest in a high-quality deep-cycle FLA battery?

So I chose the Rolls, which is not cheap at $186. As soon as I got home with the Rolls, which had an April manufacture date, I checked the voltage (12.5), checked the water (about 1/2-1/4" below), and put it in on a Deltran "smart" charger (the Battery Tender 800). It stayed on the charger overnight, in the morning it was floating at 13V (and I noticed the water level was now right up to the bottom of the opening holes, though I didn't test s.g.) I kept it floating for a few days, then took it off and checked the voltage a few hours later: 12.7.

I just put the battery in the boat and my charge controller's amber battery status light went on immediately (according to the Morningstar Sunsaver the cutoff is 12.1 volts for the amber light). I didn't have my voltmeter with me so I couldn't double check but that was worrying. I have to admit I don't trust this battery so far and I'm not too keen on going out on a trip with it. It's now hooked up to a 40W solar panel on the boat that runs through the charge controller, we'll see what it does, but something's not right. After 3 days on the deltran charger at home it should've been topped right off. Am going on a trip in the boat tomorrow, will take a voltmeter and check it out, but something's not right and I'm worried this might be a defective battery. Or maybe the Battery Mate didn't push it up to the absorbtion voltage or it didn't absorb long enough, but why would a brand new battery be so low voltage?

[Mike90250]

New batteries sit on a shelf until they are sold. If fresh stock is placed in front of old stock ....
You may want to get a couple cycles on it and check the SG, and see if it's right or not. In fact, do that now.

Best to return a dud now, instead of AFTER the holiday, least it looks like a battery rental !

[Megunticook]

New batteries sit on a shelf until they are sold. If fresh stock is placed in front of old stock ....
You may want to get a couple cycles on it and check the SG, and see if it's right or not. In fact, do that now.

Battery date code indicates it was manufactured in April. And Rolls just shipped it to the dealer 2 weeks ago.

Best to return a dud now, instead of AFTER the holiday, least it looks like a battery rental !

Unfortunately I'm taking the boat on a trip today, dealer is 2 hours away, and I don't have a spare batter (gave him the old one). I probably better call him and see what he says.

[PNjunction]

At a minimum, your charger / maintainer should be capable of at least .05C, which in this case for an 85ah battery would be about 4.25A, not something dinky like the 800ma Deltran maintainer.

Part of that reason is that batteries that have been sitting around or are stationary for long periods of time, will stratify the electrolyte. You need a little bit of bubbling to make sure the electrolyte is um, not separating like oil and vinegar (differing amounts of water and acid in this case). Your usage will be in a sailboat which will help mechanically do this mixing, but if they have sat around for awhile, you'll want to recharge with at least .05C and then drop into float.

Part of the reason is that as a safety measure, the Deltran will time out and drop to float too early if it cant reach the proper absorb voltage and stay there in time. It assumes you have a bad battery. You may want to disconnect, and reconnect it again and see what happens.

Also note that most Deltrans are designed for AGM voltages, unless you specify a specific model. I'd double check the Deltran voltage spec against what Rolls recommends for that battery.

If it's ok, I'd be sorely tempted to recommend that you upgrade to one of the 5A models, and not these little tenders to make sure you aren't stratifying the electrolyte.

[Sunking]

No mystery what is going on here. You may think the Battery Tender is a charger, but it is not. It is a over priced Trickle Charger which is made to keep a fully charged battery charged up and is not capable of charging a battery in any meaningful amount of time. It is only a 800 ma Trickle Charger. It would take it a week or more to charge your battery. Your battery requires a 10 amp charger or 12 times more current than the Battery Tender can supply.


Even with your 40 watt panel is way under powered as it can only charge at 2 to 3 amps (need 10 amps) and could take a few days to fully charge your battery. You need at least a 150 to 200 watt panel or a 10 amp AC powered charger. You can use the 40 watt panel or battery Tender for now, but it could take a few days. No worries about the battery for now, but you need to get it charged up and put several cycles on it to form the plates. But be warned if you were to discharge it to say 50% DOD, even with your 40 watt panel is going to take a few days to recharge.

If your boat has an auxiliary engine with an alternator, start it up and use the alternator to get charged up. Bottom line here is you are way under powered in chargers and solar. Even your 40 watt panel is basically a Trickle Charger. It will keep a fully charged battery charged up while docked, but a piss poor under powered charger. It will take 10 amps to cause agitation of the electrolyte and charge in a meaningful amount of time.

Amp Hours = Amps x Hours
Hours = Amp Hours / Amps.

So you have a 85 AH battery and a 0.8 Amp Charger So assume your battery is at 50% DOD or 40 AH. How many hours to recharge using a 0.8 amp charger and efficiency of 80%??

40 AH / .8 Ah x 1.2 = 60 hours

Even with the panel will take a long time because you only get roughly 4 Sun hours and at 2 amps is 8 AH per day or 3 to 6 days using the above example.