Michael, if you treat each consecutive pair of 6v batteries in a series bank as a single 12v battery, you are good to go. Just make sure no charging cables are connected to ground. The outputs of modern smart chargers are isolated. If you go with a single series of 6 6v batteries, you only need one 3 bank charger. Using GC2 size golf cart batteries as an example, you will probably have between 215 and 230 amp hours capacity at the 20hr discharge rate. That is probably no less than you have with the existing 12v batteries if they are common group 31 or whatever. So unless you want to double your capacity, just get 6 6v golf cart batteries. If you want more capacity, install a second bank but you should consider keeping them isolated, using only one bank at a time. There are also 6v batteries of higher capacity like the L16 size, for instance.
So, let's say you have 6 golf cart batteries and you number them, from the negative end of the series to the positive end, 1 through 6. Take one positive and negative pair of charging leads, connect the negative lead to the negative terminal of #1, and the positive lead to the positive terminal of #2. There. One 12v charge is going to 12v worth of cells, just as if it were connected to a single 12v battery. The second pair of charge leads has the negative lead connected to the negative terminal of battery #3, the positive to the positive terminal of #4. Finally, the last negative wire goes to the negative terminal of #5, and the positive to the positive terminal of #6. Nothing should be connected to ground.
It would be better if you had 6 separate 6v chargers, but this will work, possibly better than a single 36v charger. If you go with two separate banks, then you will use one charger for one, and one for the other.
The only real problem is that ideally the bulk charging current for a flooded cell battery is about c/5, or 20% of the capacity rating. I doubt if your 3 bank charger can make 40+ amps per pair of charge leads. Even 30 amps. Well, sometimes we make compromises. But with reduced charging current, the importance of occasionally performing a proper equalization charge is exponentially higher. This is probably best done manually, as I have never ran across a "smart charger" that delivers high enough voltage for equalizing. That will be about 7.75v for a 6v battery, or 15.5v for a 12v battery. I think the manufacturers are simply afraid people will cook their batteries to death or have an explosion or something. Well, there is something to that paranoia. You MUST carefully monitor a battery being equalized. It is not something that I personally would trust to a microchip. YMMV. An old fashioned transformer type charger fed from a Variac, with a trustworthy ammeter and voltmeter, AND a pair of eyes and hands constantly watching, will gitter done. You set it to the 12v setting, and charge one 6v battery at a time, adjusting the voltage with the variac. I don't use a charger at all for this, just a variac and a rectifier from an old stick welder. It is pretty easy to zap yourself if you are not extremely careful, possibly even fatally zap yourself, so be very serious about doing it right and using safe working practices. If you elect not to equalize, its not the end of the world, but you will probably reduce your battery lifespan.
---In electricboats@yahoogroups.com, <consultativeskills@...> wrote :
Yes, I'd like to keep the same chargers. However, they are currently configured to connect to 3 batteries [12v] each. What's your thought s on how I would take those same set of 3 charging cables on each charger and connect to the 6 six-volt batteries in the two groups?
On Tue, Jun 6, 2017 at 9:40 AM, Jeff LaCoursiere jeff@... [electricboats] <electricboats@yahoogroups.com> wrote:
That isn't correct - 12 x 6v in series would be 72v. The OP was originally correct - 2 sets of 6 x 6v, the two sets in parallel.
I'll throw out a guess that you could then keep your original chargers, and use them in the same manner - just charge each 36v bank just like before.
j
On 06/06/2017 07:33 AM, Daniel Michaels nov32394@... [electricboats] wrote:
They would all be in a series. One battery charger. Same as a golf cart.
I recently bought a 2002 Canadian electric boat Fantail Launch. It has 36v system, with two groups of three 12v batteries in series, then the two groups linked in parallel. There are two ProTournament series 3-step marine battery chargers, each dedicated to one of the 3-battery groups.
I fear the current six 12 v Interstate batteries are approaching end of life, and I'm interested in changing over to the 6v golf cart batteries with the higher amp hours capacity.
I need a 36 volt system for the current motor. So, would I be linking 12 of the 6v batteries: two series of 6 in parallel? Would I need two more charges to charge the added 6 batteries?
Thanks, and Regards.
M Kirkwood
--Mike Kirkwood
consultativeskills@...
www.InternalConsultativeSkills.com
Consultative Skills education and consulting
Sales Performance Skills training and Coaching
O: 952 472 4043
C: 612 532 7161
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a New Topic | • | Messages in this topic (21) |
No comments:
Post a Comment