AGM & TPPL - CHARGING TEST

[Canuckjetboater]

As promised, here is some data on TPPL battery charging with a single engine Yamaha (2020 SX195). The challenge was to find a battery that the single engine (SVHO 1.8L) Yamaha with OEM stator charging system could charge to 100% without the help of a 110V shore powered charger or charging on a trailer at home. That is, a wet slipped Yamaha jet boat deliberately slipped at docks with no shore power. Early days results: I have anchored 5 times now using the Yamaha OEM stereo for hours at a time. I have run it down to 12.2 volts several times. This would indicate a +/_ 40% discharge. There was no trouble starting the boat although I always travel with a mini lithium-based battery booster capable of 1000 charging amps - just in case as IMO -40% discharge is "getting down there". At idle (1250 RPM +/-) the charging voltage on the boat's voltmeter and on an independent meter is 13.9/14 volts. Also good news is that with as little as 30 minutes underway at 5000 RPM the boat's stator charger powers the boat's needs AND returns the battery to 100% charge (12.8v - 12.9v) as indicated by a meter. This is the same charge that it leaves the dock with. I have been told by a friend at the marina a local owner's 2020 195 Yamaha shows a maximum charge at 1250 RPM 12.4/12.5 amps. That is a significant difference and I would love to put the same meter on both boats. If there is indeed a difference of .5+ volts charging between the two boats, that IMO would be significant difference. IF this is accurate I attribute the difference not to a difference in the charging out-put of the stators (although possible) but to the charging "acceptance" of the TPPL battery chemistry. A huge benefit of TPPLs is that they "accept" more amperage AND do so dramatically faster than a flooded, gel or even their AGM brothers. A forum member wisely suggested a solar charger (with controller) could be helpful for me, as a wet slip boater (with no shore power). I think that was a wise suggestion, however, at the moment, the OEM stator is working perfectly. I realize my comments are directed at wet slip boaters. I must say that having our boat in a wet slip is waaay better than the daily launching we did last year - and that was only our Yamaha SVHO PWC. It is so much better to just drive to the slip, remove the bow and cockpit covers, warm the engine and take off - no waiting and launch ramp drama. Where IMO TPPL technology would benefit single or dual engine Yamaha jet boats (who can use 110v chargers to daily charge) would be for a member who had a massive stereo or other draw-downs such as a 12v on board refrigerator etc. In that case a couple of TPPLs would be awesome, particularly if they were group/series 31s. My battery is a Northstar TPPL group 24.....(you may remember I deliberately chose a group 24 as that was the biggest IMO battery that a single engine OEM Yamaha stator could charge to 100%) As of today, my OEM Yamaha stator (unaided) can run my stereo at anchor and with a short trip at reasonable RPMs power the boat's needs AND charge the battery at the same time. More to come, if relevant! Also time will tell if the stator is actually NOT fully charging the battery as it will accept less and less charge. In which case - solar charger or back to the drawing board for me!

 

[212s]

As of today, my OEM Yamaha stator (unaided) can run my stereo at anchor and with a short trip at reasonable RPMs power the boat's needs AND charge the battery at the same time.

Hey @Canuckjetboater was looking for posts about batteries and stumbled on this from July...missed it previously. By the end of the season, were you still happy with the charging ability of the stator?

We didn't have any issues all summer with our House battery running the Connext screen, Fusion stereo with a digital amp pushing around 50-100w while floating (can't crank it or we can't hear anybody!). Most days we have a 20-30 minute or more ride back to the ramp so never had any issues not getting a full charge either.

 

[Canuckjetboater]

Hey @Canuckjetboater was looking for posts about batteries and stumbled on this from July...missed it previously. By the end of the season, were you still happy with the charging ability of the stator?

We didn't have any issues all summer with our House battery running the Connext screen, Fusion stereo with a digital amp pushing around 50-100w while floating (can't crank it or we can't hear anybody!). Most days we have a 20-30 minute or more ride back to the ramp so never had any issues not getting a full charge either.

@212s......yes, the stator charged the battery fully on each trip out. Once the boat sat in its slip for nine days without anything (solar or shore) charging the battery. The next time we were back to the slip and I turned on the gauges the battery showed full charge, then fired right up. I first bought AGMs (4) for a 32 foot cruiser I had and realized how much faster they charged, how much longer they lasted before discharge while in use (Ah and Res. Min.) and how long they maintained full (within a few percent) charge when left for lengthy periods. The next cruiser we had had 6 AGM batteries. About a year after I bought those the TPPLs became widely available. I just missed getting them! So when we bought the 2020 195S I gave the HD Interstate group 24 that came with the boat to a friend and bought a group 24 TPPL (Northstar). That TPPL (as I expected) was quite a bit better than even the "regular" AGMs that have I used. For my type of situation it was (luckily) the perfect answer.